The cap for my slave cylinder is cracked and needs to be replaced. My concern is that air is now in the hydraulic system and if I simply replace the cap, that the slave cylinder will explode when I depress the clutch. Is there any other adverse side effects I should be looking for? I went to the dealer to get a replacement part, but they only have the whole slave/master setup for $120 Any idea on where to get just the cap? Thanks, Joe

 

well, If you really think air is in there bleed it. you can find the cap at a junk yard easy. look for manual grand ams, s-10s, f-bodys, sunbirds ect. they all have the same cap

 

Is it necessary to bleed the system? I mean, the top of the cap has separated from the rest of it, so I know it's not an air tight seal. I'm not real familiar with transmissions, so I wasn't sure if air would get into the system and if it would be a problem (I had read that an unbled system was likely to blow a slave cylinder upon operation.) Is there anywhere I could just get a brand new one? Thanks for the response.

 

As long as the brake fluid in the reservoir hasn't run low, there should not be any air in the system.
The only real way to 'blow' the slave cylinder, would be to operate it if it were disconnected from the bellhousing. If there were any air air in the line, it simply wouldn't have as much throw as it normally would.

Pete

 

O.k., I replaced the cap, and it did the same thing

When I replaced the cap, all of my clutch noise went away. A day later, I noticed the cap was kind of bubbled at the top, like it was under pressure. The next day, the clutch noise returned. Today, I found the new cap damaged just like the old one.

Any idea what could be causing this? Did I just get a bad cap, or is there something causing my clutch hydraulics to be under to much pressure?

Thanks, Joe

The old cap:

 

The new one:

 

Are you filling the reservoir up as high as possible and then sticking the cap on?

When you place the cap on there, the rubber diaphragm will displace some brake fluid, usually spitting out when you secure the cap. I usually just fill the reservoir a bit less to allow for the diaphragm. My cap is black, from a 91 RS, not a huge deal im sure but just something i noticed.

I have dealt with the slave setup about 4 times now...involuntarily of course. Sounds like too much pressure if its "bubbling the lid."

To cause physical damage like that..there is only 2 ways....from heat or pressure....and even though something under pressure will become hotter, it is unlikely that this is your problem...i would just say faulty cap or too much pressure...try a bit less fluid.

 

Thanks for the response! This pic shows my fluid level, does this look too high? What would be the best way to remove some of the fluid? Thanks, Joe

 

I wonder if you have something in the fluid. water, ps fluid ect. is the rubber insert swollen up? how does the fluid look? I have had people come in with there brakes draging so bad the car would not move only to find out they put p/s fluid in the master for there brakes. not only will the seals swell up but, when they get hot at all the fluid expands and locks up the brakes.

I doubt the fluid level is the cause because the rubber diaphram will push out the extra fluid when you put it in the res.

 

I doubt there's anything in the fluid b/c I haven't touched since I got the car in 2001, and this problem has only been recent. Could a lack of fluid cause this problem? I.E. if there is air between the fluid level and the diaphram, could it cause a problem?

Thanks for the help guys!

 

The recommended fluid level is to the 'step' in the reservoir, just above where it's shown in the picture above. Air between the top of the fluid and the diaphragm won't hurt anything.
There should be a small hole in the top of the cap to equalize the pressure between the two sides of the diaphragm; make sure it is cleaned out.
To me, the two damaged caps look like they have just been tightened down to far. Finger tight is all they need.

Pete

 

The hole in the top of the cap was clear on both caps. I thoroughly cleaned the new cap before I installed it. That's why I was so surprised that it was bubbling and eventually cracked because I assumed any excess pressure would escape out the hole or the little valve on the side.

I'll see if I can get a new cap tomorrow and just lightly tighten it (I made sure the new one got on good and tight )