Master/Slave Cylinder Reliability

[88911coupe]

Replaced my master and slave cylinder late early last year with parts from our host. Thoroughly flushed system and they are already failing...again. If I put pressure on pedal it will slowly sink and I can pull it back up and then drive without too much trouble, so long as clutch not depressed too long. No leaks...I've seen this situation before. Is there any option to buying a new set that may be more reliable that whatever is being made and sold these days? Possibly more robust seals from a rebuild kit? Changing these is a total PITA, even if the parts aren't too pricey. The first ones lasted about 15-20 years as I recall.

[88911coupe]

OK....follow up question...it appears there are now more than one manufacturer of these two parts...anyone have any opinions on who makes the better one?

[manbridge 74]

I buy these from Porsche. Yeah you pay a lot more to have some guy check for quality assurance but rarely do I have a come back on these. Like you said, a difficult r&r.

[88911coupe]

Yes, that may be best...I just noticed these have a 2 year warranty. I've never returned anything to Pelican for warranty, not sure how that would work since I can't say for sure which one has failed. Although when I replaced these they had both begun to fail so that may be the case now as well.

[steely]

Buck,

Just a dumb question, but did one of them happen to start leaking or did they just fail?
I replaced the Brake Master because it was leaking.
Brand ATe from PP.
I also replaced the master and slave clutch cylinders while I was in there. (torn boots, age, difficulty during operation, but no obvious leaks that I could find).
It's been about 4 years now fyi.

[88911coupe]

In my case, this has now happened twice since I've owned the car (nearly 17-18 years) the pedal will slowly drop when depress if I put pressure on it and just hold it there, no leaking at all. Then I can just grab it with my toe, pull it back up and it will work fine but I can't just depress the pedal and hold it. What appears to be happening is the fluid is getting past the seals but not leaking anywhere. I rarely drive the car any more so it's frustrating that the seals are not lasting too long. I flushed out the line the last time and there was some "dirt" which actually looked more like really old seal material that has broken down over the years.

[Chuck.H]

Just curious, is your clutch pedal stop on the floorboard adjusted correctly? I could see over extending the cylinder causing premature failure.

I like my stop adjusted just a little past full clutch release, and I make sure I hit it each time I shift. (I'm one of those that treat my shifter lever like it has a raw egg for a handle).

I'm still on my original M/S cylinders FWIW.

Chuck.H
'89 TurboLookTarga, 433k miles

[88911coupe]

Chuck, that is a very good point, I have wondered if maybe I have it adjusted to where its going down too far. The method to set it in the Bentley manual, IIRC, is a little hard to implement accurately. I'll have to try again when I replace them this time. Thanks