NSW Corvettes
Technical Tips => Brakes, Suspensions, Steering, Wheels & Tyres => Topic started by: anychevy on March 21, 2012, 04:49:31 PM
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Before I start pulling things apart and ordering parts, I though I should get some advice first.
#1 Get in the car and the brake pedal goes straight to the floor, but will pump up and hold, but sometimes slowly drops to the floor again.
Inspected all brake lines, hoses and calipers for obvious leaks, but all dry.
Haven't noticed any loss of fluid in the resevior, but it's only been a day.
#2 Brakes pull hard to the right and again, nothing jumps out as obvious, calipers look o.k. no leaks and the hoses look good on the outside.
It feels like the right caliper grabs the rotor and a split second later the left grabs. Very scary !
I think there's air in the system and the piston cups in the MC are probably gone, but it's the pulling to the right that has me baffled.
The previous owner said "it's always been like that"
Any ideas if (like I suspect) bleeding does nothing ?
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Probably the flexible hose on L/hand side is collapsed/blocked inside. Replace all four if one has gone. Use a bottle of fluid on front & another for rear to flush out all old fluid.
Maybee a siezed piston in l/hand caliper? Mixed set of disc pads, different composition.
A new master cylinder is only about $150 probably the old one has rust in the bore down past where it would normally operate when pedal goes to floor causes small scores in seals which allows fluid past seal
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Grab a mate, clamp all 4 lines and press on the pedal while your mate releases one corner at a time. You should feel the pedal move slightly when the clamp is released (normal) and when you get to the dodgy corner the pedal will move a lot.
If the pedal moves a lot when all of them are clamped, it is the master cylinder.
If you have a dodgy caliper, get online and buy some new ones! I've never had any real success reconditioning old calipers. I had a similar problem with my 71 and bought new ones - no problem since! (and it cost less than getting them reco'd)
May as well get new rubber lines while you are at it. For $100 for 4 it sure beats $40 each to get made up here in Aus.
:beer:
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If you have a dodgy caliper, get online and buy some new ones!
May as well get new rubber lines while you are at it. For $100 for 4 it sure beats $40 each to get made up here in Aus.
Thanks sirfixalot & 77CVT
Do you guys know a good US source for brake components ?
I'll definately get pads, hoses and maybe front calipers (the back look pretty new)
The MC is just the single outlet type, so I'm guessing that won't be too hard to get fixed locally ?
LHF caliper looks newer than the RHF and the pads are different brands, so it looks like "Bubba" had a go at it.
I'll bleed it first, just in case there's air. Then start start testing things.
Thanks again
Cheers
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Mate can you post of photo of the master cyl.
single out let does not sound rite But I am not up on variations on your model
IN any case a single out let would not supply adequate volume to all four calipers.
Bfit
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Mate can you post of photo of the master cyl.
Same as this, single outlet in front.
http://www.cssbinc.com/1965-1966-corvette-master-cylinder-non-power-brakes.aspx
The dual oulet MC was standard with power brakes from 65 and non power brakes from 67
I just had another look over the brakes and the LHF calliper is now leaking from somewhere (it wasn't before I drove it yesterday)
So, I'm now thinking a complete front brake kit is what's I'll need, 2 callipers, 4 hoses, 4 pads and a master cylinder.
The back looks all pretty recent, so I might just get hoses just to be safe.
Where is the place place and which type of calliper ? SS O ring or "LIP" seals ?
Thanks guys.
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Clamp the LH line and see if you have pedal - if not keep going around until you do. If you don't then start with a new MC.
Any flex in a rubber line will cause a slight pedal drop.
If you can get o ring caliper go for those. I got mine from Ecklers but shop around (freight will be heaps!). Not sure if your club gets a discount.
:beer:
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Ponti world in wollongong https://pontiworld.com.au/usgmsp/index.php?cPath=239_242&sort=2a&page=2has the calipers recoed no exchange I have a single system master cylinder off a 65 which was working when removed for upgrade to power brake dual system, you could get that one recoed to save time
Ponti world booster & master cylinder $357, Caliper front $237 & includes a set of pads. Hoses for 68-82 $73 for 4 not sure what the difference is for 65.Ecklers lists them for 63-82
You would also need the proportioning valve & a couple of new hard lines
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I have a single system master cylinder off a 65 which was working when removed for upgrade to power brake dual system, you could get that one recoed to save time
Mate, that would be a huge help. I'll U2U
I don't think I need a proportioning valve, the single system uses a smaller diameter front line from the distribution block (I think)
But I'll check the AIM and hard lines appear all o.k.
Dave has the calipers (with pads) and hoses (same) in stock, so I might get this thing to stop this weekend, with any luck.
And I have to drive through Sutherland to get to Dave :drink:
So please give me a call.
Cheers
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I've bought lots of stuff from VBandP including braided flexi lines and o-ring overhaul kits. They have specials all the time, which helps. Shipping can hurt though.
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Replaced both front calipers, pads and new flexi hoses all round.
Still got a little air in one rear caliper (inside bleed nipple frozen solid) but it stops straight and I have a hard pedal now.
Looks like the master cylinder is reasonably new and not causing any issues.
But all 4 rear bleed nipples are rounded, so I need to replace them and bleed the back again.
And man, they hold alot of fluid, used 2 litres !
Does anyone know where I can buy bleed nipples here ? (I like saying nipples) :rolleyes:
Cheers
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I'll have to check, but I think I have a set of new stainless ones to suit C3 calipers that are in my left over parts box.
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I'll have to check, but I think I have a set of new stainless ones to suit C3 calipers that are in my left over parts box.
Thanks Scott
Same caliper from 65-82 (so I'm told) I need the 4 rears, if you have them ?
Would like to get rego next week and take it down to the nationals if possible.
I sent a U2 with my number so we can work something out.
Cheers
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I'll have a look when I get home tonight and get back to you.
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I'll have a look when I get home tonight and get back to you.
Thanks Scott
VB&P list the same part from 65-82 front & back, so I guess they're all the same ?
http://www.vbandp.com/C2-C3-Corvettes/C2-C3-Brake-Products/C2-C3-Brake-Components/1965-82-6-SS-Bleeder-Screws.html
Cheers
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Same same.
:beer:
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I only have 2 nipples. :grin:
I also have 2 of the stainless plugs to go in the bottom holes of the caliper. I'm not sure why I only have enough for 1 caliper though. Strange.
You should be able to get them from any decent parts store though, or any brake place. Just take one in if they aren't sure.
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You should be able to get them from any decent parts store though, or any brake place.
No worries Scott
I'll try the 2 bleeders out of the old front calipers if all else fails
That should work.
Thanks for having a look anyway.
Cheers
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If you are desperate I have got some from Hopper Stoppers before.
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Drowned them with WD40 for a couple of days, a big pair of vise grips, a bigger hammer and alot of sweat and foul language.
I swaped the front 2 (which were still good) onto the LHR
I'm sure Bubba had a go at this and just gave up. :shake: Anyway, I'll bleed them later and hopefully that's it !
Thanks all for the advice
Cheers
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Mate it may sound odd
but wet them up with the WD
leave for a time
get a hammer not to large and give the end of the nipple a wack straight in
like a nail.
the compression will have the tenancy to loosen it then just screw it out.
You might be surprised just how easy it will come out
that is if the hex has not already been rounded off.
only use a single hex spanner. on them.
another useful tool is an impact screw driver
you can take the driver socket of and fit normal impact socket on, good for loosening difficult fittings.
Bfit
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Mate it may sound odd
but wet them up with the WD
^ You could do the same and heat it. The expansion and contraction can also loosen it.
s
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Mate it may sound odd
but wet them up with the WD
leave for a time
get a hammer not to large and give the end of the nipple a wack straight in
like a nail.
the compression will have the tenancy to loosen it then just screw it out.
Yep, that did the trick, they were completely rounded, so had to squash them flat to get the vise grips to hold, but they came undone eventually.
Yeah, Steve, I almost went and bought some freeze spray, (which shrinks it) but didn't need it in the end.
The pedal is alot harder now but still alot of travel ? I know the non boosted system uses more leverage via the upper hole in the pedal, but it still feels like it might have a little air in there, I'm not not sure.
I'll take it for a drive tomorrow and see how it feels.
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Mate it may sound odd
but wet them up with the WD
^ You could do the same and heat it. The expansion and contraction can also loosen it.
s
Yes heat is a wonderful tool
and heat and quenching can loosen up things that seen impossible to move
One must be mindful of the materials being worked on
the repercussions can give a result that is expensive.
A commercial hair dryer is handy for general heating.
good for fitting bearings etc
be careful with one of these they can turn a bearing blue in a very short time
When fitting the new nipples make sure to use a good anti-seize on the threads
Lub the seat with a little brake fluid
Bfit
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Yes heat is a wonderful tool and heat and quenching can loosen up things that seen impossible to move
When fitting the new nipples make sure to use a good anti-seize on the threads
That would have been my last resort.
I put a little grease around the thread, seemed to work o.k.
Cheers guys.
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Yes heat is a wonderful tool
and heat and quenching can loosen up things that seen impossible to move
One must be mindful of the materials being worked on
the repercussions can give a result that is expensive.
I learned that trick heating the screws in a guitar, the wood expands then the screw shrinks.
A commercial hair dryer is handy for general heating.
I used a soldering iron to heat the screws.
s