Hey guys, recently I bought a 1987 Coupe that had tranny problems. I quickly diagnosed the rusted slave cylinder to be the problem that they described on the window as "Bad Clutch". Much to my dismay, after I replaced the slave, I couldn't bleed the system. I started it in gear and gave it a test run to see if there were actual clutch problems, and there definitely were. It would slip pretty noticeably when any throttle was applied. So 3 months later I'm sitting here after I've changed the clutch, and still can't get the hydraulic system to bleed. I have replaced the slave cylinder, and am thinking of doing the same to the master cylinder. The problem that happens when we bleed the clutch is that we can't get any pressure to the peddle. When we pump the clutch up, and release it, it just kind of splu, and we've gone through at least 2 bottles of brake fluid. If one of the seals in the master cylinder is bad, could it possibly be letting pressure pass by and therefore not pressurize the system? That's about all I can think of now. It's kind of irritating when you can replace a clutch, but bleeding the line completely stumps you. Not to mention it's sitting outside just waiting to be driven
Here are a couple pics from when I first got the car to now. As soon as the car's driveable I'll probly either have it repainted black or try to take off all the clearcoat and either re-clear it or try to keep it waxed enough so that it doesn't get nasty.
The day we picked it up
The engine bay that day
Problem found
Engine compartment after (needs to be cleaned.... again)
I bench bled the slave before I installed it, that way I got most of the air out even before I bleed the system. To do this all you do is pour fluid in it where the clucth line would hook up. You then push in where the rod would go with your finger to work the air out. Once the slave cylinder is full of fluid you are done. You can then hook it up to the hydraulic clutch line and install it on the tranny. Open the top on the master cylinder and make sure it is topped off and kep it topped off during the procedure, then crack open the bleed valve on the slave. You could also jack the front of the car up a bit to help. This will gravity bleed your system. I used a rag on the tranny to catch the overflow but you can attach a plastic tube to the bleed nipple and let it flow into a jar. To make sure you get all the air out you can push the slave rod into the slave body but make sure you close the bleed valve before you release it or it will suck air back in. Once you are sure no more air is in your line you can close the bleed valve and finish toping off the master cylinder.
If this didn't work you might have a faulty master cylinder. Try looking under the carpet where the banjo connects to the master cylinder for leaks. In my car the slave was leaking air in and didn't show any external signs of leakage. I noticed it had trouble going into first gear and I had to press the pedal to the floor to get the clutch to disengage. The clucth pedal feel had changed from one day to the next. Now that I replaced the slave cylinder, it feels like new again. Hope this helps. :salute:
thx for the help aveng! I recently bled the master by pushing in on the clutch, holding my finger over the clutch line hole, and letting fluid seep back in. One thing to note is that it felt like it was trying pretty hard to implode my finger to suck it in that hole. I got some air bubbles out, and now I have more pressure to the clutch peddle, and about 1/2" to 1" of movement at the clutch arm, but still no go. I even tried further assisting the clutch arm with a large screwdriver, but to no avail. Any ideas?
I gave you a link to V8 V8Archie in old Europe. He has some troubleshooting info on is website. If you are getting an inch of travel out of your slave and you still can't disengage the clutch, you have other problems and might have to remove the tranny to examine your clutch components. Good luck. :salute:
Even new parts can suck air. I went through 4 slaves before I got a good one. All the otehrs sucked air.
Invest in a vacuum type bleeder thingie. You can get them at autozone and such. What I do is fill the master, and use the vacuum pump to suck the fluid through the line. This will also pull the air in the line too. Once I go through a bit of fluid and am confident that I got all the air out of the line, I bleed the slave.
The way I do that is I hook up the line to the slave and compress the slave rod before I hook the line up. THen after I hook up the line I release the rod slowly. This pulls fluid into the slave. I then hook up my vacuum pump again and then crack the bleeder and suck the fluid from the slave and line into the pump.
If I push the clutch pedal a few times and then go to vacuum more fluid fromthe slave and more air comes out as well, I know I have a leak.
I found the slaves go bad first. The heat cycling in the engine bay wears down the internal seals in the slave till they let air in.
A thing I did to test my slaves if they were sucking air was to hook up a clear hose about 2 feet long and the diameter of the bleeder screw. I would crack the bleeder screw and use the slave rod to push fluid up into the hose. I would then close the bleeder. When the rod would go back out it woudl suck fluid from the master. Now keep in mind I am not moving my clutch pedal at all so the master rod isnt' moving int he bore so it won't be sucking air unless the seal is really bad.
Now I would then open the bleeder screw again and push the rod in allowing the fluid to go up into the clear tube again. If air comes out you know its sucking air. Especially if you do this like 10-15 times and each time the same or close to the same amount of air comes out. Or if you can actually feel where its not sealing when you push the slave rod in a difference in resistance and more air comes out at hte same spot of the travel of the slave rod.
After trying to get my 88 formula clutch system to work on and off for 2 months, I became an expert at diagnosing and bleeding/reparing the system.
dirty sanchez, I just replaced the clutch & to bearing, did you actually look at the pictures in the post? haha. I am getting alot more pressure today after I got the master bled, so I'll give it my best shot tomorrow and see what I can come up with. Oh yeah, I know that the pedal isn't bent, that's the first thing I looked at.
What I meant by examining the clutch parts was that you need to make sure that they were installed correctly. Your forks could be off the throw out bearing (I pretty much doubt that is the case) or your clutch disk could be on backwards (more likely scenario). If you are getting a full inch of travel out of the slave when it is installed, the clutch should disengage. Did your clutch disk have a sticker on it telling you which direction to mount it on? You still could have a bad master or slave cylinder as mentioned above. You could also try a longer rod in the slave to give you some preload on the clutch fork. The clutch fork arm has about an inch of free play before you install the slave cylinder. If your arm still has some free play when the slave is installed, you can try a longer slave rod to get rid of this free play. Good luck I know you should be able to fix the problem.
There is no free play in the clutch arm, I can guarantee that the flywheel side went to the flywheel side, and the to bearing was clipped in there just like it came off. I am 99.9% sure that everything was assembled inside there just fine. If it comes down to it though I guess I could drop the tranny.
If the seals in your slave are good it wont' pull air. However I dont' normally vacuum the slave. I install the hose to the bleeder to catch overflow, then push the rod in, then close the bleeder, and allow the piston moving otuward to pull fluid into the slave.
well, i don't know about all that, but I went out and inspected the master cylinder to see if it was leaking today. I found that the banjo is bent pretty bad, which would lead to all the problems i'm having, correct?
Shaun41178(2) wrote:If the seals in your slave are good it wont' pull air. However I dont' normally vacuum the slave. I install the hose to the bleeder to catch overflow, then push the rod in, then close the bleeder, and allow the piston moving otuward to pull fluid into the slave.
it often will becuse the slave seal is an ubrella style - only meant to hold pressure not capable of holding much vaccum
haveing a bent rod at the master will cause problems. You aren't getting the fuel range of motion. Put in a straight banjo rod, or get rodneys. I suggest getting rodneys anyways, but to just get by you can use a spare laying around
With the new rod on there it should work perfectly.
I have a good banjo here from a bad master cylinder from an 88 gt, I'll have to see if they're the same length. We have a press here that we're going to try straightening it out with. How hard is it to replace the banjo?
There is a circlip and washer that retains the banjo in the master cylinder body. Make sure you install the banjo with the loop at the end pointing up. You will need a circlip compressing tool to remove it.
