NSW Corvettes
Technical Tips => Brakes, Suspensions, Steering, Wheels & Tyres => Topic started by: jimandemma on February 26, 2018, 05:23:09 PM
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Hi all, I have fitted new Wilwood 4 pot calipers, discs and braided lines to my 75 C3. I tried bleeding the system with a hand pump to no avail, just kept pumping through air bubbles. The master cylinder has not run dry and currently have passed around a liter and a half through the system. Tried again today using the pump the pedal and hold, crack the nipple and tighten. No air appears to be in the system now but the pedal is still spongy to the floor. Can't work it out, can someone offer some advice. I have done bleeding before on the car with no problems, this has me stumped.
Cheers, Jim
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tell me about it Jim
I spent to days last week doing the same thing .
and could not get a peddle .
Are you starting at the further calliper first and working back to the closest
Did you bench bleed the master cylinder
try opening the farther bleeder and just let it gravity free for a few hours, that's how I had to do it last time to clear all the air.
then work towards the master cylinder.
if all else fails get a set of quick bleeders
This time I what and bought a vacuum bleeder, sorted it out in 20 minuets
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Yes, started at furthest rear, inside and outside top nipples and worked my way forward to the caliper closest to the master cylinder. Have not bled the master because it hasn't run dry. Vacuum bleeder is not helping and draws air, where pedal pumping appears better with solid fluid when cracking the nipple. I have done this 3 times today in succession with still no pedal.
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You haven't mentioned if you have new pads as well.
Either way, check that the pads are flat, true and properly seated. If they are even slightly cocked, the caliper will be able to distort the pad backing plate to conform to the disk but the extra pedal travel to do so will be long, soft and squishy.
This is a common racing problem I've had where the pads get tapered by use.
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Yes, pads are new and appear properly seated and true to the disc
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If you have rubber lines, clamp all 4. If the pedal is still soft = master cylinder.
If it is hard, get a helper and release each corner one at a time. The pedal should only move a small amount if it is ok. Re-clamp and do the next corner - if a corner you release moves the pedal a lot then that is your culprit.
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if you have a second person .
crack the fitting at the master cylinder and then get the helper to slowing depress the brake see if any bubbles are present start with the rear brake line first then the front.
Bfit
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OK, tried gravity bleeding to no avail. Tried the helper depressing the pedal again and now got a whistle from underneath when cracking the nipple and brake warning light came on. Tried again, whistle gone but brake warning light on. Fluids are normal front and rear of master cylinder. Starting to give me the sh#ts. Pedal is spongy to an inch off the floor. Pumping does nothing to the height of the pedal, hold, crack the nipple, no bubbles, pedal to floor, tighten nipple. No change with all 4 corners. I'll try the master next, cracking the lines.
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Remove the switch sender and reset the valve,
That can be the problem, I have not seen it but I have read that others have had this as the problem
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No worries, will try tomorrow.
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Cracked the lines at the master cylinder and a few bubbles came out of the front line. Reset the proportioning valve cylinder and have no brake warning light now. Bled brakes again with some air coming out of the front calipers inner nipples. Did all this with the master cylinder line on and clamped. Rear boot sucks down but front doesn't. No difference in pedal!!! I give up!! Have to get someone out to fix this as I'm beyond my capabilities
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Correction, master cylinder cap on and clamped.
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Don’t give up if it worked before you changed calipers then it will work again.
May be some one has a pressure bleeder.
Members anyone have one.
Bfit
Ps what Sudurb are you in
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North Arm Cove, 45km north of Newcastle. I'll buy a pressure bleeder and try that Friday
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I suspect you still have air in the front half , hence it’s not pulling the oil down in that chamber.
Do you have assess to gear to make a brake line.
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I have access to gear to make a brake line. It's pulling the fluid down in the front cylinder but not the front boot on the cap as the rear.
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but not the front boot on the cap as the rear
not sure what you mean by the above
BFit
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Inside the master cylinder cap there are 2 expandable rubber boots that stop fluid swishing around when the level is down. When using the pump the pedal method bleeding the rear calipers, the rear master cylinder cap boot will get sucked down with the level bled from that rear section of the master cylinder. When bleeding the fronts, the front master cylinder cap boot does not expand with the fluid drop in the front section. I have also been bleeding with the engine running, so going to try again with the engine off, no booster.
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Seriously, try and clamp all 4 lines. If you pedal is hard then it's not the master cylinder. Granted, I've only ever done this on cars with a booster but should produce the same result.
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If you can make up a line with about enough tubing that you can loop over the top and back into the reservoir below the fluid then you can see what’s happening
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I've got a hard pedal with engine off, soft to floor when running. Thinking maybe a booster problem now or vacuum
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That’s interesting,
Have to think about that
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I'm wondering if that noise you heard was the booster?
I think you need to block the master cylinder at the master cylinder, and see if you can get a peddle with and with out the engine running.
a couple of dummy lines with the tube silver soldered closed.
T prove that section is working correctly.
Bfit
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Noise seemed to come from underneath the car, maybe the proportional valve. What I can't understand is the system was perfect before the brake change. I'll try another bleed this time with engine off, then also check for vacuum leaks at the booster. It's looking like I'll require a professional to come out and diagnose.
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1 when you have a good pedal, hold the brake hard down with your foot, and start the engine
the peddle should push back against your foot as the vacuum builds up. but not drop .
let us know
2 what brake hoses did you use? you said earlier they are braded but what kind and what size.
3 what was your pedal like before you changed the callipers ( what was the travel short or go nearly all the way to the floor)
4 something else to check
loosen the master cylinder push it forward a little and see if there is a fluid leak back into the master cylinder.
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Started car with foot on the pedal, straight to the floor.
3/8" external diameter braided lines all corners as supplied with the Wilwood brake package
Pedal was good before I started with short to half way travel
Will try moving the master cylinder Sunday to see if there is a fluid leak
I reckon another bleed with the engine off with no booster is in order. Will do that Sunday as well.
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Brake line
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Brake line rear
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Disc and caliper rear before
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Disc and caliper after
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Good quality brake lines they won’t expand to any noticeable extent.
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Another thought:
Go to a hydraulic shop and buy fittings/bleeders to close the end of the lines to the caliper. That will totally eliminate the caliper from the equation. You are then only dealing with the master cylinder and plumbing.
Bleed the lines as you would a caliper and see if there is any difference. If none, then the fault is entirely in the plumbing and nothing to do with the calipers. If the pedal is hard this way, then the fault is within the caliper. You can then by trial and error figure out which caliper is at fault.
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The fitting on the caliper end of the brake hose is AN3 ( 3/8 24 JIC ) these are not a common hydraulic fitting ,
Aeroquip 900599-3S is the plug if you need them.
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Bled the system again, this time with the engine off. First, I bled the bottom nipples and was surprised that air and old brake fluid came out of the nipples, especially when I have put nearly 2 litres of new fluid through. I then bled the top nipples and then top and bottom again. Little difference in pedal feel. Guys, I'm just going to get somebody around with more knowledge to fix this, I've had enough of dicking around with this for 8 days.
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What was wrong with the old one - except for the fact that they are G.M.
Are they still serviceable?
Have they been s/s sleeved & overhauled. I can see the paint.
You most likely know where I'm going here.
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Discs had a slight warp and was not sure if the calipers were rebuilt in the past with SS sleeves. Wanted to upgrade to drilled discs and lighter calipers as well as improve aesthetics. No, not going to put the old ones back on, gone too far for that.
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I understand the frustration
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I haven't read the whole post but I am guessing your having problems bleeding the brakes.
The only way I could bleed my brakes with Wilwood and standard calipers was to use a pressure bleeder. I tried for weeks doing pump and hold, gravity and a vacuum pump with no luck.
Using the pressure bleeder it took about half an hour to get a rock hard pedal.
(https://imagizer.imageshack.com/v2/150x100q90/923/kOiCWu.jpg) (https://imageshack.com/i/pnkOiCWuj)
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Yes, thinking the same mate. Pressure bleeders are damn expensive though for 1 job. Got a mechanic coming out this afternoon, so will see how we go.
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Yes, thinking the same mate. Pressure bleeders are damn expensive though for 1 job. Got a mechanic coming out this afternoon, so will see how we go.
good luck
I hope he sorts it for you quickly .
For my part I would buy a pressure bleeder it always useful even if you never use it again. A pressure bleeder was my next purchase after the vacuum bleed I purchased.
the vacuum unit I got worked a treat
Vacuum Brake Bleeding Kit T&E Tools QS-2119K
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Yes, thinking the same mate. Pressure bleeders are damn expensive though for 1 job. Got a mechanic coming out this afternoon, so will see how we go.
I can't remember how much it cost but I don't think it was that much. It gets used often enough (not just on the Vette) to justify it.
You could make one easy enough. When I use the pressure bleeder I don't put any brake fluid in the pressure tank. I just keep the master cylinder topped up. I clamp the top plate onto the master cylinder and then pump 10 psi into the tank.
10 psi head pressure on the MC is more then enough to force any air out of the system. It's then just a matter of opening the nipples in order to bleed. Because I don't put fluid in the bleeder tank, after each caliper I release the air pressure and remove the top plate off the MC to top it up with fluid again.
A cheap garden sprayer from Bunnings, a flat steel plate (with a rubber gasket) clamped to the top of the master cylinder and a nipple on the plate to join the hose from the sprayer will do the same thing.
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I’ve seem a how to on a us forum to make one of these out of a weed sprayer .
Google it
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no luck with mechanic, pressure bleeder next
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It's not fancy but it's cheap.
Doesn't need a gauge as 10 psi is only about ten pumps. The master cylinder top plate can just be a flat steel plate held on with a large G clamp.
https://www.corvetteforum.com/forums/c3-general/2905428-homemade-motive-type-power-bleeder-for-14-a.html
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^ The last time my Vette brakes were bled, that sort of bleed device was used.
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This is the one I’d make it out of
http://www.hardwareshoptoyou.com/h2u-ebay_wordpress/wp-content/uploads/2017/05/FireShot-Capture-51-Hardware-To-You_-http___www.hardwareshoptoyou.com_h-e1494652679631.png
When your finished use it I’m the garden
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Got a brake specialist coming out Thursday, so will keep you guys in the loop.
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I have seen the brakes on a vette test the best of mechanic's.
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How did it go
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He never turned up! Had to re-book for Tuesday. In the meantime, I tried forcing fluid through the bottom nipples to the top with an oil can and hose. Got some bubbles out, but the oil can died. Getting another today and will continue. Pedal still the same though.
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I get very very p==sed off when tradesman don’t turn up .
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I get very very p==sed off when tradesman don’t turn up .
Who doesn't?
And to not take the trouble to call and reschedule simply says that we don't matter.
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Brake guy came out this afternoon. Clamped the lines and still a soft pedal, engine off. He checked the system and with clamps off, everything working, calipers moving front and rear. He believes it could be the proportioning valve, if not, master cylinder but 9/10 the valve. I pulled the master cylinder last night to check for leaks, nothing. So the question is, could it be the valve and if so, where to get one here in Australia or NSW?
No brake light is showing on the dash.
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Ponti world tel:02 4257 1230
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Thanks Bfit. What do you think, the valve maybe?
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Did he use a pressure bleeder?
I've been through the same thing thinking it's the valve, master cylinder etc.
The problem with C3 brakes is there are too many places for air to get trapped.
I had the same problem with standard calipers as with Wilwood calipers.
10 psi of head pressure on the MC sorts out the problem.
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No pressure bleeder mate, it all comes back to that though doesn't it. I"m going to buy one and try it first I think. Problem is, where in Australia do you get one???
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Just make one as stated in a previous post.
Garden sprayer and a flat plate to clamp onto the MC.
The plate can be a piece of steel, aluminium or maybe even wood. Just use a thin sheet of rubber as a gasket between the plate and MC. Hold it in place with a large G clamp. Then join the hose from the garden spray to a nipple on top of the plate. The nipple does not have to protrude into the reservoirs. You only need to be able to seal air pressure between the top of the fluid and the flat plate.
About 10 pumps of the sprayer should be enough for sufficient head pressure. Just keep a eye on the fluid level and don't let it run dry.
I will see if I have any pictures I can post.
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Thanks Bfit. What do you think, the valve maybe?
I have read that the proportioning valve can cause these sort of problem , I personally can’t see how.
I have not striped a valve out of a 75 model , I’m familiar with the earlier models.
Which control rear whell pressure with what I would call a modulation valve.
The spool moves to restrict the port area to the rear hence reducing the pressure.
I’m thinking do you have any line pressure valves fitted , your original calipers should have springs behind the pistons to keep the pads out .
If you have no line valve to hold residual pressure in the lines , then that can cause this problem.
What I don’t get , if I read your post correctly .
With the line clamps , soft pedal yes
Removed clamps and hard pedal . If that’s right it is odd to say the least.
I have to say I do not agree with clamping brake lines.
Now when I had wilwood calipers I did not have line valves, I always had to two tap the brakes the get a full pedal
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Pedal feel is the same with or without clamps
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Mate I would start are the beginning again.
I know you will say it’s all be done, but it’s not working and they are a simple hydraulic system , and air is the most likely cause of a soft pedal
Try taking the bleed nipples out and grease the threads to restrict air passing through the threads when bleeding with a vacuum blender
I forgot to ask did you block the outlet ports at the master cyl, to prove the cyl is not bypassing inturnally
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Normally brake fluid goes into the pressure bottle to keep the master cylinder full, however I find this to messy. I just keep the master cylinder topped up.
(https://imagizer.imageshack.com/v2/xq90/923/lviLG3.jpg) (https://imageshack.com/i/pnlviLG3j)
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I'm going to get that Motive pressure bleeder. I can make one, but for the sake of $100, I'll buy it.
Bfit, didn't block the master outlet ports.
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There is a company in WA selling the Motive , I may still have the info I’ll look
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Just make sure you get the correct plate for your master cylinder.
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https://www.gumtree.com.au/s-ad/theodore/other-parts-accessories/brake-bleeder-motive-products-power-bleeder-model-0252-new-/1177999531
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That’s a good price with the aluminum top plate Bob :thumb:
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Yes for that price it won’t last , most of the scams on gumtree seem to be out of Melbourne .
Hopefully this is legit
He has other car gear for sale which is a good fell thing
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Just rang and bought it. He thinks the problem is the valve as well, so I'll get both.
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Thanks for that Bfit, owe you a beer or 10 one day
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Beers Ok, but dont offer Honey, esp from a full bottle.
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Thanks for that Bfit, owe you a beer or 10 one day
Mate ,looking forward to seeing you and your vett on a run soon, Peter C has one on in the near future
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I can’t find a photo of a sectioned 75 model valve, it does appear from photos that the 75 has a proportioning spool in the rear line.
I do not see how the valve could cause the soft pedal, unless the fail section has shuttled and has trapped air in the line. If this was the case one set of calipers will not bleed any volume of oil.
If you remove the valve . I’d pull it apart to investigate how it functions.
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OK, will do. Might be a while though.
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I can’t find a photo of a sectioned 75 model valve, it does appear from photos that the 75 has a proportioning spool in the rear line.
I do not see how the valve could cause the soft pedal, unless the fail section has shuttled and has trapped air in the line. If this was the case one set of calipers will not bleed any volume of oil.
If you remove the valve . I’d pull it apart to investigate how it functions.
I agree Bob, if the valve has failed then the front or rear circuit should not bleed any fluid. If the switch piston has moved it should also bring up the brake warning light.
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In the older cars pre 73, the original valve, people call a proportioning valve>
Is just a manifold with a spool to trigger the switch, in those bodies the oil will pass through, with the spool shuttled either way.
later vehicles have what looks to be a proportionating valve in rear and a metering valve in the front distribution port
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OK, so I've got the pressure bleeder kit
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I've pressure bled all top nipples at 12 PSI, solid fluid from all nipples front and back. Pedal the same!!!
Looking at changing the Master Cylinder as I think I have torn the seal with the pump and hold method of bleeding pushing the pedal to the floor.
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Was the master cylinder new or the original?
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New in 2009, 5000 miles on it since. No problems prior to the upgrade.
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I don't think it's the proportional valve as I have fluid from all calipers and calipers are working
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Sounds like that's all it can be then!!!
Did you bleed the master cylinder?
Another thing you can try is gently tapping the calipers with a rubber mallet when bleeding to dislodge any air.
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Master Cylinder
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Haven't bled the master on advice
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Why not bleed the master cylinder
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Did you fit wilwood front and rear calipers sets
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I was told by the brake specialist that bleeding the master cylinder was only necessary if it has run dry, which it had not. Yes, front and rear caliper sets, discs, lines and pads, all Wilwood.
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Well there is some truth, if the new calipers were fitted and lines connected at the same time as old calipers were removed .
The set up,you are fitting is gre same I have just taken of my car.
I had a hell of a job bleeding them , it was alway ain’t in my system , and when I did get a peddle it was 1’’ off the floor, hence I mensioned earlier I had to two tap the brakes every time .
I had no booster and 1’’ master .
What master do you have 1’’ or 1.125’’ (1 1/8’’ )
If you are still soft on the peddle bleed it again
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They were fitted new for old straight away
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Ok I would think the problem is in the rear calipers.
Remove the front mounting bolt on each rear caliper and lift it as far as you can .to get ther air to the bleeders. You may have to take both out to tilt enough to bleed. Make sure you keep caliper on rotor.
That’s how I bleed my rears to get a peddle.
You can stand the fronts up more as well if needed
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Have already done that mate
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Well rock and a hard place
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Have you bleed from the fitting on the rear of the calipers 3/8’’ JIC fitting , I’m thinking to,isolate all,4 calipers with a male 3/8’’ Mic plug bleed each fitting and see if you have peddle.
If yes
Start engine and see if peddle is still good
Then connect one caliper at a time and see what you find
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We clamped all 4 lines to the calipers and still soft pedal, so that has taken the calipers out of the equation. This was after bleeding vertical, top and bottom nipples. It has to be either the master or proportional valve. I'm taking the valve out of the equation as all calipers are working and bleeding solid fluid at the same rate, also no brake light activated on the dash. But, wouldn't be the first time I was wrong.
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I’m running out of ideas,
my background training says start all over again, take it all apart inspect everything and assess everything.
Including the new parts
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Ha, I've already given up mate. First time I've been stumped with a relatively simple hydraulic system. Just waiting on Wilwood for a recommended Master Cylinder. That's the next step in the saga.
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I just fitted one of these wilwood 261-13270-P master cylinders
And two full days to get the air out of the system
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At least with a new master, I can bench bleed then use the pressure bleeder for the rest of the system. 2 days ain't bad, I'm at 3 1/2 weeks and still going, lol.
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I guess you have to try it.
The next question is what bore size to get
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Going to go 1 1/8". Just waiting on advice from Wilwood.
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I went that size as well
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great minds think alike
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I got mine here on ebay
http://stores.ebay.com.au/surplussalesaustralia/_i.html?_nkw=Wil&submit=Search&_sid=1016250459
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I am using the same Wilwood calipers, 1 1/8" bore Wilwood master cylinder and replaced all hard and flexible brake lines.
Once I have the pressure bleeder setup it takes less then half an hour to bleed the complete system and to get a rock hard pedal quite high up on its travel.
I didn't bother to bench bleed the master cylinder and figured if need be I could do it on the car.
Looks like the last thing it could be is your master cylinder.
Other thing is the system takes quite a bit of fluid. When I use the pressure bleeder I don't fill the actual bleeder tank I just keep the master cylinder topped up. This means I have to release the pressure from the tank, remove the top plate and top up the master cylinder at least six times for each of the front and rear circuits (making sure I don't run them dry).
Doing this I then know that the first master cylinder full of fluid is getting bled through the system and any air that may be high up in the system is getting forced out.
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Are you using the standard proportional valve?
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Are you using the standard proportional valve?
Yes, I am using the standard 71 valve, however in that year it's more of a distribution block.
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This is a common problem every one changes calipers & master cylinder when i did my C3 years ago I removed the proportion valve disassembled cleaned & re-assembled with rubber grease. Had to blow it apart with compressed air. Have never had a problem since pedal is rock hard. I cleaned all lines with compressed air separately. Then flushed with metho used a bottle each for front & rear. I used a caulking gun nozzle on the bottle & squeezed bottle to force metho thru lines. Then compressed air let air dry for a day then reinstalled prop valve with new hoses, calipers, m/cylinder. Have been on car now for 15years have changed fluid a couple of times since with no problem.I also bled with back up in air furthest to nearest calipers
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Well, got in the Wilwood master cylinder and bench bled it first
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Set the push rod to the right length on the booster so it was touching the piston and attached the master cylinder, fluid still in it from the bench bleed
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Had to bleed the brakes using the pump and hold method as the pressure bleeder master cylinder attachment was too short. Solid fluid from nipples, no air?? Will have to make another pressure bleeder attachment to fit the Wilwood master cylinder. Pedal still goes to the bloody floor!!!
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Should I start now on the proportional valve?
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If you pm me your address, I will send my larger pressure bleeder cover that fits the wilwood MC.
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PM sent, thanks mate.
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Sounds like you need to have a barbecue working bee at your place one weekend soon
Bfit
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With a sleep over Bfit, he is at NCLE.
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Anytime, welcome anyone on here
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If the situation is the same after Easter, invites are going out. Plenty to do here when the weather is nice.
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Looks like Lake Macquarie. Very nice, now very enviouse.
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North Arm Cove
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Oh! Nth Arm Cove in Port Stephens opposite Soldiers Point.
Very nice spot.
Used to be good fishing out and around the Islands.
Good scuba sites, esp the deep trench infront of the port and marina at Nelson Bay.
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Took the proportional valve out as thought the switch had locked it out, nup, centered (well, didn't hear a click when I removed the switch). I'm going to get a new one anyways.
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Looking like the proportional valve piston is stuck. Took it apart today and could not move the piston. In the picture it looked centered, but have found that the switch pin is supposed to sit in a divot. When looking down the switch hole, you can see the shaft of the piston, not the divot. Must have done this when bleeding using the pump and hold method. Also found out that a bleeder tool is to be placed into the switch hole to stop the piston moving during the bleeding process. New one on the way, will keep everyone updated on the 'saga'. Jim
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You look like becoming the clubs brake expert!!!!!!...
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Looking like the proportional valve piston is stuck. Took it apart today and could not move the piston. In the picture it looked centered, but have found that the switch pin is supposed to sit in a divot. When looking down the switch hole, you can see the shaft of the piston, not the divot. Must have done this when bleeding using the pump and hold method. Also found out that a bleeder tool is to be placed into the switch hole to stop the piston moving during the bleeding process. New one on the way, will keep everyone updated on the 'saga'. Jim
Progress , BUT wait till it’s actually working before the party.
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No party yet until all is working for sure.
Am an expert in these brakes now though, plus have every possible tool to do the job as well now.
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Good tools a useful even if you never use them. Oh what do you do for a crust
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A man can never have enough tools in the garage, especially people like us that like to do our own work avoiding the so called "specialists", knowing it's done properly.
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Will be interesting to see if the proportioning valve is the culprit
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Will be interesting to see if the proportioning valve is the culprit
I’m sceptical , but you never know until you give it a go.
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Changed the proportional valve, pressure bled the system with 2 1/2 liters of fluid in the bottle. Got a small amount of air from the front right, solid fluid from the rest of the caliper nipples. I have taken around a liter from each top nipple, all solid fluid, no bubbles. Pedal still to the floor. I give up!!
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Changed the proportional valve, pressure bled the system with 2 1/2 liters of fluid in the bottle. Got a small amount of air from the front right, solid fluid from the rest of the caliper nipples. I have taken around a liter from each top nipple, all solid fluid, no bubbles. Pedal still to the floor. I give up!!
Mmm
You now have wilwood master yes?
What year booster Do you have?
Did you have booster out of the car ?
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Have a Wilwood Master Cylinder correct to the caliper setup
Not sure on the brake booster year but looks relatively newish
Booster hasn't been out out the car.
Might look at the push rod length as I think I made it a mm longer to piston contact when fitting the Master Cylinder to the booster. This could be closing off the compensating port.
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Did you fit the aluminium adapter in the master cyl. That is used in the later booster set ups.
The booster push rod should only just touch the spool in the master cylinder ,
It’s a fell thing, only just enough to keep the plunger/spool of the cir clip in the rear of the master cyl
What happens when you pump up the brakes to get a peddle , hold it down and start the engine.
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Did not fit the alloy adapter, push rod was long enough. It was pushing the piston 1 to 1.5mm when tightened to the booster.
Pumping brakes to get pedal with engine off goes half pedal and doesn't improve
Holding down and starting engine, goes straight to the floor.
I've taken the master off, will take accurate measurements with a digital vernier, adjust the push rod and bench bleed the master cylinder and try again Tuesday.
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If you can get an assistance measure the stroke you are getter at the booster.
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ok
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Make sure there is no vacuum in the system
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Master Cylinder has approximately 23mm of piston travel
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Correction. Master cylinder has 28.5mm of piston travel
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That should work ok
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I know. I'll re-adjust Tuesday when I have digital verniers to get absolute correct measurements
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Perhaps check for a buckled pad which isn't sitting flat against disk
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Pads are good and parallel to the discs. Clamped the lines to the calipers and had the same problem which discounted them from the equation
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Have you replaced the master cylinder its the only thing it could be. The other thing i have seen is the caliper put on upside down putting the bleed nipple facing down............ I have to ask the dumb questions IT is facing up?
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"Clamped the lines to the calipers and had the same problem which discounted them from the equation "
Then it is the master cylinder.
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Yes, replaced the Master Cylinder with a compatible Wilwood one. Calipers are in the correct orientation.
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77CVT, clamped the lines with the old master cylinder. Got a new one, same problem, ARGH!!
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Try this; bleed brakes. clamp all 4 brake lines. if pedal is rock hard master is in working order. if not master is problem. if master is ok take clamp off 1 caliper at a time testing each time till you find when it goes soft. your master can also be wrong size to piston size of caliper.
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Paul
I think he has don't all that,
something is not working correctly
and may be its the new flexible brake hoses.
Jim can you make up some blanks to block of the lines at the chassis brackets
and see if you can get a full pedal
Bfit
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Thats cool but at what point then did the pedal go soft?
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Boshie what do you know about going soft .!!!!!!!
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Soft only goes with those in NURSING homes or do they now call them Senior Resort style living.
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Boshie what do you know about going soft .!!!!!!!
''Soft''! its an age thing, its what's know a cyclic fatigue. caused by a long exposure to repetitive condition.
usually closely followed by oldtimes ( Alzheimer's )
Now
re read, so you remember what we are discussing
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Soft only goes with those in NURSING homes or do they now call them Senior Resort style living.
I thought is was called, The waiting room.
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Update on the Wilwood Brake Saga. So far I have:-
Fitted Wilwood D8-4 Front and Rear Replacement Caliper Kit, BP-10 compound "Smart Pads", Wilwood vented and cross drilled discs, Braided lines
Vacuum bled the system with a hand vacuum, but was getting air past the threads on the nipples
Pump and hold method, solid fluid from top 2 nipples with no air bubbles
Gravity bled each top nipple x8 for an hour each
Pressure bled the system with no fluid in the Pressure Bleeder tank at 12 to 15PSI
Replaced the master cylinder with a Wilwood 260-8556-BK Master Cylinder Alloy Black Anodized 1.12 in. Bore
Bench bled the master cylinder and fitted with the bleeding kit installed, Booster push rod at 1.5mm longer
Pressure bled the system, air pressure again only on the fluid in the master cylinder.
Pressure bled the system with 3 litres of fluid in the holding tank, a litre from each top nipple x8
Used an oil can and hose on the bottom nipples forcing fluid through the tops, some bubbles
Removed master cylinder, adjusted push rod to have 0.5mm clearance to piston, bench bled and refitted.
Pressure bled the system again, 0.5 litres from each top nipple, solid fluid.
Replaced the standard proportioning valve with a Proflow Disc/Disc Brass Brake Proportioning Valve
Pinned the proportioning valve piston at the switch point and pressure bled the system, solid fluid from all nipples
Put the system under 15PSI of pressure, cracked each union working from the master cylinder, proportional valve to the calipers. Little to no air.
Bled the master cylinder on the car, small amount of bubbles.
Bled the system using the pump and hold method, small amount of bubbles. At times pedal would not go to the floor when bleeding the rears unless you completely released the pedal and then started again.
*** Still a spongy pedal with engine off***
*** Pedal to an inch off the floor when the engine is running using the booster***
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Been watching.
This has gone from a quick Forum story to the "Never Ending Story".
I now have new found respect for you. I absolutely hate being beat by a machine.
But by this point I would have spat the dummy and burnt the car to the water line.
I suppose the only question now is - What to do next ?????...
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Have you checked the seals in the calipers.
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I have no idea!! I'm going to get blanks and block off the caliper lines and work from there. Thought once or twice to burn it to the ground, eh.
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Seals appear to be fine in the calipers, but I could be wrong.
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Just use vice grips and clamp all the lines. Take one clamp off at a time and check pedal before you take the next clamp off.
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Hard to clamp the lines as they are all hard lines or braided. When we clamped the lines before, actually dented the braid.
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put the rubber hoses back on and do the tests if you are still having the problem then its not in a hose. If you are not having a problem replace one hose at a time until you find the offending hose.
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Don't think it's the hoses, has to be a fault in the calipers maybe.
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Hello I know that you are in Newcastle --but before you burn your car loaded on a trailer and bring it to Sydney to SR Performance at 15 argyle at Wolli Creek Steve sharky will fix it ( corvette experts) 0439901560 --regards Jorge-vette club 🍻🍻
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Just use vice grips and clamp all the lines. Take one clamp off at a time and check pedal before you take the next clamp off.
If you still have these wildwood lines fitted make some blanks to block the lines at the hard line on the chassis mount.
this is what you need if you can`t make some thing up
Edelmann Inverted Flare Plug Fittings 120300.
they are probably available from Aeroquip as well.
if you are carful you can use a 3/8" unf bolt for this and a O-ring one for each fitting you want a BS010 o-ring
put the o-ring in the fitting and nip the bolt down onto it . do not over tighten .
bleed by loosing the bolt.
any questions PM me for a contact number,
eliminate the cheep parts first.
you can try taking the callipers off each disc fit a block of wood in each 2mm smaller that the disc width and pump the pistons out and push back by hand to bleed air , then refit.
you can do this with caliper on, if you have an old set of pads. but don't pump the pistons out of the calipers
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Do I crack the nipple to bleed air when pushing the caliper pistons in?
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put a little weight on the pistons and crack the bleeder
do one side of each calliper at a time.
MP me your contact number and Il ring you tonight .
bfit
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PM sent BFIT
Jim
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No luck, going to take the car to Steve Sharky at SR Performance the weekend after next. Thanks Jorge.
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No luck, going to take the car to Steve Sharky at SR Performance the weekend after next. Thanks Jorge.
that's sad Jim
Im sure you wanted to sort it your self , but some times one just has to bit it bullet.
Bfit
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Yeah, after 2 months of trying, had to call it. Frustrating for a problem solver to not solve the problem.
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Well, put the wheels on yesterday afternoon after adjusting the handbrake. Off the jacks and a couple of to and fro's in the garage to see what little braking effort I had. Brakes effective enough an inch off the floor. Hand brake was good, so took the car for a drive to bed the pads in. Pedal slowly getting better as the bedding procedure went on. Still spongy, but a better feel now. Still going to take the car down to Sydney Saturday to get it looked at, but appears to be getting better. Reckon it needs another bleed, but I'm over bleeding now, time for someone else to have a go.
Jim
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just a thought .
did you fit Residual Pressure Valves
Bfit
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I did not fit Residual Pressure Valves as the Master is higher than the caliper pistons
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they are advertised for that purpose however they help with knock back problems and also bleeding the system.
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Ah, ok. See what happens with SR Performance next week and I'll let them know.
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Any updates for us? I would love to know the cause of your issues.
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Sorry guys, away with work. Bedded the brakes in again, gravity bled the system, found a bit of weeping at the hose connections to the calipers, 0.020" gaps at the piston to pads which, after bedding in, starting to close up with the piston seals getting some use. Also raised the brake pedal at the booster 14mm. I honestly think the problem was not bedding in the brakes and then re-bleeding, as every time the pedal was getting better. Then dynoed at 254RWHP with 375 ftlbs of torque. Happy again.
Jim
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Hey Jim glad that the boys at SR Performance helped you with the brake problems -enjoy your ride--regards Jorge --vette club 👍👍👍
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Yeah, thanks Jorge, always the small things that get over looked.
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Hi Jim, what was the final problem found by SR Perf? My brakes went soft last week (no components changed) and they sound like exactly the same problem. I have speed bleeders, and my trusty Mityvac, however still same 1” off the floor. Did the pump and hold bleed which found a small hard line to braided flex line leak (FRS), tightened up and bled again for solid fluid, same 1” pedal again. Master cylinder is about 8 years old, but very low miles. I get a small spirt up through my front brake system when the pedal is pressed quickly. I assume that my front pot piston seal is worn, but before I go through the whole component change out test, re-test, re-test, etc, etc exercise of this 15 page (and many months exercise), I figured that I’d ask what the problem was before repairing or upgrading...
Thanks, Matt
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Quick update on this. Pressure bleeders are the bomb. Made a hell of mess until I got the seal right, but brakes are hard as a rock now. EVERYONE NEEDS TO BUY ONE 👊