Clutch issue with new BDR

[vref120]

Guys, just wanted to get your input on an issue I just started having with my clutch. Been in contact with my builder, but just want to see what some of you think or suggestions before I start ordering parts and which one to try first.

The clutch pedal started losing pressure. To best describe it, it seems that sometimes the pedal gets soft and as such, the engagement of the clutch is all over the place and not in the normal spot that I was used too when releasing it. Tonight however, I had the clutch in at a red light and the car started to lurch forward with the clutch engaging and died. Almost rear ended a Vette.
I have no visible leaks anywhere and fluid level remains the same. With the car off, if I depress the clutch (more like lightly push it, the distance to get pressure is either immediately or almost to the floor or somewhere in between. Very random) I can hear a squirting sound (when I don't get resistance) which I'm assuming is the master cylinder. I've bled this clutch 4 times with no effect. The clutch engaging at the red light was a first tonight.

The slave cylinder seems fairly common in these cars and should be easy to fix. The master cylinder looks to be a royal PITA.

As a side note to better help ya with your thought process, I've had the slave cylinder and transmission off the car 4 times for another problem I'm working on, but we never disconnected the lines, just laid it and the bracket up on the frame to get the tranny off. Not sure if it's related or not.

Master Cylinder or Slave? Neither.

Talk amongst yourselves but let me know.

[madmaxx]

i assume you checked the clutch fluid level? strange no leaks but you are loosing hydraulic pressure. slave cylinder super cheap. don't let clutch reservoir run empty when you replace use cling wrap under the clutch master cylinder cap, if not you will have to bench bleed the clutch master cylinder, in other words remove it. I would check level, if level is good than bleen the slave cylinder just like a wheel cylinder on brakes very easy and quick with two people if that doest work post and i am sure somebody has another idea. I had an old triumph spitfire that leaked internally on the master cylinder but than again it was 20 years old.

[vref120]

Thanks Madd. Yea, I've bled the slave 4 times so far with no effect or making the situation better.

[GLS-BDR226]

What kind of movement in the slave shaft are you getting when you depress the pedal? It sounds like a bad master cylinder or the master needs to be bled as madmaxx suggests.

My BDR has 12,000 miles and I've never had to replace the master, only a couple of slaves. But I never had the problem you are having. When my first slave went out the pedal went to the floor and the clutch wouldn't disengage. And it was leaking around the rubber boot.

[RICK LAKE]

vref120 This is going to cost you a first name. Start with Clois Harlan Great guy, knows alot about cobras and fixes. Lives in your town.
Your sound is air in the system. Is the master cylinder below the slave? We need to vacuum the system or manual bleed with 2 people. Does your slave have a bleeder valve or scharder?
Best why without a machine is too push rod at slave to full depress postion and crack valve. pump up pedal and repeat this about 6 times. Run a clear tube that will seal over the scharder valve and keep this in fluid after the first opening. Make sure the brake pedal stay compressed and valve is closed before releasing pedal.
Last note, what color is the fluid? I know the new fluid is clear but was the old fluid black? Gravity bleeding doesn't work on all systems. Pressure bleeds work most times. If you do this and have the same problem looking at a slave cylinder. The clear tube will tell you if your system has a sealing problem. 99% of the guys don't have this but having a pressure gauge in the line will help tell you if you have the correct pressure and the system is not bleeding down. Good luck. If my explaination is hard to under stand call me and I will walk you through this easy repair. Rick L. 732-254-3536.

[cbreez]

Unlike what was previously posted, a slave cylinder going bad WILL lose hydraulic pressure with plenty of fluid showing in the master cylinder. They leak internally. Don't bother with the master cylinder at all, change out the slave, bleed all of the overheated fluid out and be done with it. With a clutch system use either silicone, dot 3, 4 or 5 fluid, it doesn't matter as you don't have extreme braking heat just engine heat.
I just changed my 4th or 5th in 8 years last week. Crappy system.

[Cashburn]

Sounds like a defective Master Cylinder. You don't see evidence of fluid on the floor mat or running down the inside foot box? We see them from time to time here right from the factory. On most of our current builds we are losing them for a remote setup anyhow.

[Cashburn]

BTW does your master have a white cap?

[Grey 65]

Sounds like the master cylinder.... Mine went out @ about 3,000 miles....

Kevin....

[vref120]

Yes, mine has a white cap on it.

[vref120]

Ordered a new Wilwood unit from Summit. Gonna try that and see. The unit in the car is not a Wilwood. Not sure what it is.

[Kobura]

How did you know what replacement part to get? Is it covered under the Backdraft warranty?

[vref120]

Kobura: I just asked James at Radical Roadsters which part number i needed. I'm unsure what kind of part I would get if I ordered it from Backdraft as it does not describe it and didnt want this same unit, so I just ordered it from Summit. The Part number is 260-1304 for the Wilwood Master Cylinder off Summit. The slave cylinder is from a 88 Mazda B2000 in case you need to reference it later.

Waiting for the part to come in, then me and Clois (thanks buddy)will stick it in hopefully this weekend if he finishes his big project.

James at RR is on vacation or he would have sent me one overnight. Wanted to get the parts sent my way so I'm not sure. It was only $58 including shipping.

[GLS-BDR226]

Originally Posted by Cashburn

Sounds like a defective Master Cylinder. You don't see evidence of fluid on the floor mat or running down the inside foot box? We see them from time to time here right from the factory. On most of our current builds we are losing them for a remote setup anyhow.

Jay, on the BDR parts site I saw where they sell a remote mount clutch master.

Backdraft Parts - clutch master cylinder

Is this what is going on the new builds? It looks good but where does the reservoir mount? From one of the pictures it looks like it mounts to the top of the firewall over the steering column but I can't see where I have the room to do this or a place to attach the bracket. I have an early build. Thanks for your continuing advice to BDR owners.

[vref120]

Looks like it's on the opposite side of the brake booster from its current location.

[Cashburn]

Originally Posted by vref120

Kobura: I just asked James at Radical Roadsters which part number i needed. I'm unsure what kind of part I would get if I ordered it from Backdraft as it does not describe it and didnt want this same unit, so I just ordered it from Summit. The Part number is 260-1304 for the Wilwood Master Cylinder off Summit. The slave cylinder is from a 88 Mazda B2000 in case you need to reference it later.

Waiting for the part to come in, then me and Clois (thanks buddy)will stick it in hopefully this weekend if he finishes his big project.

James at RR is on vacation or he would have sent me one overnight. Wanted to get the parts sent my way so I'm not sure. It was only $58 including shipping.

Hmmmm ...

[Cashburn]

Originally Posted by GLS-BDR226

Jay, on the BDR parts site I saw where they sell a remote mount clutch master.

Backdraft Parts - clutch master cylinder

Is this what is going on the new builds? It looks good but where does the reservoir mount? From one of the pictures it looks like it mounts to the top of the firewall over the steering column but I can't see where I have the room to do this or a place to attach the bracket. I have an early build. Thanks for your continuing advice to BDR owners.

Shoot me an email. We have a full kit with bracket and reservoir. Next year I hope to have our real parts site up.

[vref120]

Cars fixed. Turned out to be the slave. Leaking into the rubber boot, but not enough to leak on the ground. Glad it wasn't the MC. I'll keep the Wilwood for later.
Thanks to everyone for their insight and help.

[ront49]

Originally Posted by Cashburn

Sounds like a defective Master Cylinder. You don't see evidence of fluid on the floor mat or running down the inside foot box? We see them from time to time here right from the factory. On most of our current builds we are losing them for a remote setup anyhow.

My slave had no leaks or seeps...couldn't find and on the master either until I looked inside and there, was fluid (more like graphite) oozing down the firewall, down in back of the carpet and crapping up underneath the car...ordered from Iconic Parts a new wilwood master and slave. hopefully all connections will fit. Big issue is getting to the master clutch cylinder...side vent off??? any suggestions???

[spdbrake]

Ron,

Take a look at the last post in this thread.
Clutch or ??
and a parts list in the this thread
Backdraft slave cylinder