3fingersalute

Ok, I have an 87 2WD PU that's rock solid other than clutch issues I've seem to been dealing with on/off now for a year or two. Originally it was losing fluid and I replaced the slave cylinder with a cheap one I bought from the local auto parts store. That didn't help with the leaking and I couldn't ever find where the fluid was going so I came here and got some great advice and found that it was actually leaking out the master cylinder, back through the firewall so I replaced that with whatever my local auto parts store had in stock. That took care of my issues for a while but now I'm having issues again.

So now what it is doing is not leaking, but seems to lose pressure. If the truck sits for a while (while at work or overnight or when not driven for a few days) I can hop in it and pushing the clutch goes right to the floor with no resistance and I have no clutch. If I sit and pump it for a while it will slowly build back up to where I can use it. I tried bleeding it, that worked to get it going but the problem still remained the next time. I went online and ordered an Aisin slave cylinder and replaced it, but that made no difference either.

So what should I try next? Should I replace the master with a better quality one? Should I look at replacing the line? It's not leaking/losing any fluid at all but it acts as if it gets air in the line all the time.

Any help/suggestions would be GREATLY appreciated!

kdgolds

Man I hope you figure this out. I have an 88 doing the exact same thing. My only idea right now is to replace the master and the slave again and all the tubing just in case there is a small pin hole somewhere. Best of luck

3fingersalute

Well, I guess I'll give the master a go first with a better quality one since it was a white box special I used last time. It's fairly easy to replace and not expensive at all. If that doesn't work then I'll try the line, but like I said I'm not losing fluid at all.

Romans117

I get most of my stuff from autozone. Including master cylinders, brake and clutch, slave as well. Only once has the part not preformed the way it should. That was a 99 chevy fuel pump.


If you have to pump it up it is not bled correctly or is letting air in. You didn't say if you were adding fluid this go around. The clutch system is very very simple. Bleed , add fluid, bleed, add fluid. Don't run the master cylinder dry or you have to begin from square one. No short cuts.

92yoterDD

Do you by any chance have a vaccuum pump? I have one that works great for diagnosing a leak. I attach it to the top of the matter cylinder and pump it up then see if it holds vacuum. If it doesn't then you have s leak somewhere. It is very possible to be sticking in air from one of the fittings and not lose fluid. You should run about 2 qts through the system to ensure its bleed all the way.

3fingersalute

Thanks for the replies. I'm not adding/losing fluid at all this time. I'll give it another go at bleeding first and see if that helps, I definitely didn't put anywhere near 2 quarts through it...

Bills86e

I had same issue, leaking.

DAMPENER HOSE : it jumps from fender to engine to take the vibration stress a metal pipe can't.
That pinhole had me scratching my balls for a year!

Bills86e