Author Topic: Bled new Wilwood brakes but still spongy pedal (Read 124078 times)

jimandemma · « **Reply #120 on:** March 25, 2018, 05:54:45 PM »

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.

jimandemma · « **Reply #121 on:** March 26, 2018, 07:53:50 PM »

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

Vettech · « **Reply #122 on:** March 26, 2018, 08:05:59 PM »

You look like becoming the clubs brake expert!!!!!!...

bfit · « **Reply #123 on:** March 26, 2018, 08:08:58 PM »

Quote from: jimandemma on March 26, 2018, 07:53:50 PM

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.

jimandemma · « **Reply #124 on:** March 26, 2018, 08:16:29 PM »

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.

bfit · « **Reply #125 on:** March 26, 2018, 08:19:10 PM »

Good tools a useful even if you never use them. Oh what do you do for a crust

jimandemma · « **Reply #126 on:** March 26, 2018, 08:23:14 PM »

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.

sirfixalot · « **Reply #127 on:** March 31, 2018, 11:06:46 AM »

Will be interesting to see if the proportioning valve is the culprit

bfit · « **Reply #128 on:** March 31, 2018, 03:12:41 PM »

Quote from: sirfixalot on March 31, 2018, 11:06:46 AM

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.

jimandemma · « **Reply #129 on:** April 08, 2018, 11:04:10 AM »

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!!

bfit · « **Reply #130 on:** April 08, 2018, 11:22:28 AM »

Quote from: jimandemma on April 08, 2018, 11:04:10 AM

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 ?

jimandemma · « **Reply #131 on:** April 08, 2018, 12:03:10 PM »

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.

bfit · « **Reply #132 on:** April 08, 2018, 12:43:02 PM »

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.

jimandemma · « **Reply #133 on:** April 08, 2018, 01:33:23 PM »

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.

bfit · « **Reply #134 on:** April 08, 2018, 02:48:45 PM »

If you can get an assistance measure the stroke you are getter at the booster.

jimandemma · « **Reply #135 on:** April 08, 2018, 02:50:26 PM »

bfit · « **Reply #136 on:** April 08, 2018, 03:05:07 PM »

Make sure there is no vacuum in the system

jimandemma · « **Reply #137 on:** April 08, 2018, 03:47:12 PM »

Master Cylinder has approximately 23mm of piston travel

jimandemma · « **Reply #138 on:** April 08, 2018, 03:49:45 PM »

Correction. Master cylinder has 28.5mm of piston travel

bfit · « **Reply #139 on:** April 08, 2018, 04:09:34 PM »

That should work ok