Brakes

[Amon]

We can't get any pedal pressure nor is the pedal returning all the way once released from pressure. We've done the following:

1.) bled them many times.
2.) Found two small leaks and fixed them.
3.) Loosened the nuts by the pedal base to allow them to move freely.
4.) Readjusted the brake pedal so that it leans toward the driver.

We're wondering if the master cylinders are bad or maybe one is bad which doesn't allow
for it to return due to scoring in the cylinder? I have no idea why we have no pressure since all the air has been bled out of the system....

Thanks for your recommendations!

Mark

[Steve Davis]

Mark,
"No Pressure" is .. unclear in what you mean. Does the pedal ever STOP when you push it.. or just go to the floor? Does the pedal STOP, but the wheels don't?

My first guess would be the MC's need to be rebuilt. If you have a bias bar, it should be easy to see which one is 'floating down' if that be the case. However, if either is an issue, you should probably rebuild or replace BOTH at the same time.

I make a routine of rebuilding the MC's and either rebuilding or replacing the WC's at least every other year. If it's been longer than that.. just start over and replace ALL MC's and WC's and then try again. WC's are only ~$8 each and MC's can be rebuilt for about the same .. or replaced for ~$75 each.

Brakes are pretty important in racing

[Amon]

Steve,

Thanks for replying! The pedal goes nearly to the floor (1" from the beam)and it doesn't
want to return to the original position. We're taking the masters off our parts car to see if they're the problem and hopefully correct the issue. I do have some new WC's that I can use if needed.

Mark

[Steve Davis]

Remove 1 drum at a time and slowly depress the pedal while watching the WC action (2 person job) (DON'T push too hard to blow out the WC) - release the pedal while watching the WC. If the WC stays extended (likely), then open the WC bleed screw. If the WC then retracts, the problem is in the MC - if not, then it's in the WC. Check all 4 before taking any action .. act appropriately .

[kea]

You stated you have bleed the brakes numerous times.
Did you get the same fluid flow/volume from the bleeder on both ends of the car ?

[WNYVeeRacer]

Now this might sound condescending --and I know you're worked on vees for years -- but did you adjust all your brake shoes out to near race position before bleeding ? I once chased a problem like this for days, looking at the hydraulics, until I realized that the shoes were backed way off the drums and bleed 'em as much as I did & it still seemed like I had no pedal.
Once adjusted correctly, things seemed fine. It may be something as simple as that.
Dennis
( BTW looks like things at Nelson Ledges have been cleaned up Considerably-- I'll be there in Sept. Hope to see ya.)

[budawe]

Looks like folks have a lot of good ideas. I like to disconnect each end, one at a time and see if the problem is with one end of the car. Many times, one end will inhibit bleeding of the other end. This makes sure your balance beam is working ok as well.

[Amon]

We replaced the Master cylinders (with used one's), wheel cylinders with new one's and the brake lines without any effect. In response to Dennis, the brake shoes are dragging and we still have no pedal. I think we need new master cylinders or a rebuild at the least but Brian is a scratch for Pocono this weekend since we can't whoa his car!

Mark

[Chris Elwell]

I make a routine of rebuilding the MC's and either rebuilding or replacing the WC's at least every other year. If it's been longer than that.. just start over and replace ALL MC's and WC's and then try again. WC's are only ~$8 each and MC's can be rebuilt for about the same .. or replaced for ~$75 each.

Steve,

Where do you get the $75 master cylinders from? The one I need for my car is listed at $130 from Pegasus.

Thanks,

Chris

[Jphoenix]

Steve,

Where do you get the $75 master cylinders from? The one I need for my car is listed at $130 from Pegasus.

Thanks,

Chris

Summit: http://www.summitracing.com/parts/wi...0372/overview/

Sorry, that's a clutch MC, here's a brake MC from summit: http://www.summitracing.com/parts/wi...3376/overview/

[grapefarmeral]

Are you getting fluid to the master cylinder. I had the same problem a few years ago and it was like the master wouldn't prime. I loosened all fittings , pumped like crazy and finally got pressure at the wheel cylinders. You might try a slight bit of pressure at the reservoir and or suction at the wheel cylinder... don't want to see Brian scratched...

[BLS]

Chris, if you have the girling type, $50. including shipping:

http://www.jegs.com/p/Wilwood/Wilwoo...rPage=90&pno=1

[Steve Davis]

Steve,

Where do you get the $75 master cylinders from? The one I need for my car is listed at $130 from Pegasus.

Thanks,

Chris

http://www.spruellmotorsport.com/til...it-p-2191.html

[problemchild]

Sounds like you just have some dirt/debris around the wave washer at the end of the piston assembly and rebuild kits would solve the problem. I've just disassembled, cleaned, and reassembled cylinders to fix this problem many times, usually without missing a session.

[budawe]

I make it a practice to bench bleed master cylnders before installation. You can do the same on wheel cylinders as well. Make sure the bleed valves are at 12 oclock to avoid air pockets.l

[Chris Elwell]

Chris, if you have the girling type, $50. including shipping:

http://www.jegs.com/p/Wilwood/Wilwoo...rPage=90&pno=1

Thanks! That is the type I need.

[kea]

Remember, the Wilwood master is a "Girling type" and not a Girling.
As a side note, Girling prices went up after the company were acquired by the American company TRW.
My UK supplier wasn't very happy (maybe he thought it was my fault).
I will always trust a Girling unit over any copy !

[B Farnham]

Well we changed the brake cylinders, brake lines and master cylinders and nothing helped. The master cylinders we put on were old so I'm just going to order some new ones. It just wasn't meant to be this weekend, thanks to everyone for the advice