I Keep Replacing the Slave Cylinder - It Keeps Leaking

[samandw]

Hello Everybody,

I've replaced the entire hydraulic clutch system (master-line-slave) in my D100 (slant-6, 3-on-tree) several times now, and every time, after a few months, it starts dumping fluid. Is this a problem anyone else has experienced with a rarely driven Sweptline?

* Are there fluid additives that may help, or perhaps someone knows where to get a cylinder sleeved with Stainless Steel?
* Is it possible I've got it adjusted improperly, and I'm damaging the cylinder through normal use?

I'm pretty handy with automotive projects, but this one has me STUMPED. Any help/ideas/suggestions much appreciated!

[WAWII]

Funny you should post this.



Well, I went into the shop, and noticed this little puddle of fluid under the M37 (re-powered with a 1968 W200 engine/trans). Checked it out, and it wasn't anti-freeze, engine oil or fuel. It was dripping from the passenger side exhaust pipe flex joint.

Touched, smelled and checked out the fluid, kind of oily, not water, so what was leaking? Wasn't from the previous bath, and was odd to appear to be coming out of what is supposed to be a sealed stainless steel braided exhaust flex pipe. Looked again, and well, I found the source.

The clutch slave cylinder had decided to suddenly start leaking. Guess these re-built slave cylinders just don't last, at least under a warranty.

Pulled it out, and the master cylinder leaked out the rest of the fluid. Checked it out and well, it's starting to leak into the cab side, so I will have to replace/rebuild it as well. Guess even new Wilwood MC's don't last either.

I'll now be on my third master and slave cylinders, guess I should expect the clutch to go next, so I'll be on the third clutch as well. All in only 2,500 miles on the M since I built it!

The slave cylinder push rod is showing a lot of hole wear (original), so I'll build a new one to take out some of the clutch slop, and put everything back together and get Frankie back on the road for Iowa.

[wally426ci]

Everyone should just get them stainless lined through john geidl

[samandw]

Still at (six-five-one) six-five-three zero-one-four-seven? I should give him a call this afternoon . . .

[howard37]

I am having same problem , my clutch master cylinder and slave cylinder don't last 2000 miles.. ??

[wally426ci]

I think its china...

[dodgeboykim]

And my 66 had an NOS master clutch cyl put in probably 15 years back and slave not sure when I rebuilt that last time. Been years for sure. No problems for me yet.

[Hobcobble]

The re-manufactured masters and slaves from auto parts stores are hit or miss.
I've been problem free with a couple of my Sweptlines but did just recently replace
a clutch master cylinder on another one. The next brake or clutch master or slave
I buy will be from John Geidl.
John

[68fish]

i would go through slave cylinders about every 2 years. With my last one, I swapped to DOT 5 silicone. That was 3 years ago. Im one year ahead so far!!!!! I figured that if I could keep out all moisture I would be ahead. My slaves were showing rust inside.

[RussRoth]

i would go through slave cylinders about every 2 years. With my last one, I swapped to DOT 5 silicone. That was 3 years ago. Im one year ahead so far!!!!! I figured that if I could keep out all moisture I would be ahead. My slaves were showing rust inside.

I had about 5 years on my last set I replaced late September and it looked like crap in the master. Loaded with water. I think the design of the cab and the master lend itself to ingesting water besides brake fluid normally absorbing it. I think if you were to change it fairly often that would help and maybe eliminate regular replacement. I swear I am going to keep up on it this time.

[Hobcobble]

Everyone should just get them stainless lined through john geidl

Yep. X2.....
John