Wilwood clutch master cylinder leaking.

12430 Views 15 Replies 7 Participants Last post by AutoGear, 15 d ago

roger1

Discussion Starter · Sep 16, 2012

I've got a '55 Chevy with a T56 and I'm using My Wilwood clutch master cylinder and it is seeping a little.
Probably just a few drops a day underneath car.

The mounting bracket I'm using for the master is angle adjustable so the shaft is perfectly straight into the master coming from the clutch pedal.

I installed this master more than a year ago but haven't even driven the car 200 miles yet. However, it's been seeping like this since not long after I first installed it and got the system bled. Might have been from the very start but went unnoticed for a little while. The reservoir has only dropped about 1/4" over this amount of time and I've never put any more fluid in since I originally bled it.

Other than this little issue my hydraulic clutch system is absolutely perfect. It's the best feeling clutch I've ever owned.

I guess I need to get a rebuild kit for it. I'm just confused why it is giving me any trouble in the first place. Anybody else had this kind of trouble? Are these things prone to leaking?

It's leaking towards the rear of the master where the shaft enters the plunger.

Here's a pic to see how it's mounted on my firewall and it shows my adjustable angle bracket.

Here's what it looks like out of the box that also shows the remote reservoir kit I got with it.

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1 - 16 of 16 Posts

bigdog7373

· #2 · Sep 19, 2012

I would have sent it back as soon as you spotted the leak. Not every new part is perfect. Sometimes you get a bad part and have to send it back. Since it's over a year old you should just rebuild it.

Reactions: 1

roger1

Discussion Starter · #3 · Sep 19, 2012

bigdog7373 said:
I would have sent it back as soon as you spotted the leak. Not every new part is perfect. Sometimes you get a bad part and have to send it back. Since it's over a year old you should just rebuild it.

Thanks. That's what I decided to do. I ordered a rebuild kit for it last night from Summit. It was just $21.

I googled a bunch on "leaking Wilwood master cylinder" and did find a guy that reported a problem with one where he put a couple of kits in it and finally found that the bore had porosity in it and was eating up the plungers. So, I'll try this one kit and if it doesn't last, I'll replace the whole thing. This same guy went with a Tilton 76 series and he thought they were made better.

Reactions: 1

AutoGear

· #4 · Sep 19, 2012

Wilwood and McLeod seem to have their fair share of issues. I imagine its a bore that doesn't have the proper surface finish, or the seal is a little crimped. Either way, it should be replaced immediately.

roger1

Discussion Starter · #5 · Sep 19, 2012

AutoGear said:
Wilwood and McLeod seem to have their fair share of issues. I imagine its a bore that doesn't have the proper surface finish, or the seal is a little crimped. Either way, it should be replaced immediately.

Thanks. My perception was that Wilwood made top quality stuff. But maybe not.

Like I say I'll give this one shot of fixing with a kit and see what happens. I'll go with another brand if it gives me issues after that.

Here's a statement from a guy in another forum. Realize it's just his opinion though.

"One of my 3 Wilwoods leaked after 500 miles....took it apart, the cylinder wall internally was full of pits and holes, porosity in the casting. Machining on the inside wasn't very smooth either. I replace it with a Tilton 76 series, about $50 more. The quality difference of the inner bore on the Tilton is obvious, smooth and hard anodized. For $50 it is worth it since they are such a joy to replace after the body is on."

lmsport

· #6 · Sep 19, 2012

I have replaced many of the Tilton, Wilwood and Howe cylinders over the years. When racing stock cars regularly, we keep spare cylinders at all times and replaced them as soon as a leak was detected. Most would last 20-30 races, but we replaced them every winter no matter how long they had been installed. I have never really noticed a difference among the brands, but none seem to last very long. I wonder if it has something to do with the quality or type of rubber used for the cups and its compatibility with modern brake fluids.

roger1

Discussion Starter · #7 · Sep 19, 2012

lmsport said:
I have replaced many of the Tilton, Wilwood and Howe cylinders over the years. When racing stock cars regularly, we keep spare cylinders at all times and replaced them as soon as a leak was detected. Most would last 20-30 races, but we replaced them every winter no matter how long they had been installed. I have never really noticed a difference among the brands, but none seem to last very long. I wonder if it has something to do with the quality or type of rubber used for the cups and its compatibility with modern brake fluids.

Man, that doesn't sound very encouraging!

At least mine when mine leaks it drips straight down to the ground and doesn't damage anything. Sure glad I didn't go with a design that puts the master inside of the firewall behind the dash. My carpet was custom made and pretty expensive.

AutoGear

· #8 · Sep 19, 2012 (Edited)

I run into this a lot. Its our belief that these 'hot rod retrofit' Hyd. clutch setups are repackaged circle track setups, where a tiny drip isn't an issue apparently. I also think the bore corrodes from lack of use, as we don't drive our musclecars often enough. To be honest; I haven't heard of a HYD clutch kit, that has OEM build quality. Personally, Id like to see a stainless liner in the cylinder; and something that can be rebuilt.

Does anyone know of an OEM Hyd clutch system that retrofits well???? I know in 1998 GM went to a concentric slave, inside the gearbox, opposed to the externally mounted slave used up to approx 1997 (End of the LT1 Camaros/Firebirds). But even these are hard to bleed and have a host of contamination issues.

We see the same problems with Hyd. throw out bearings too.

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Joer5000

· #9 · Mar 1, 2014

Roger its Joe over in Phx with the 57 Chevy, i am scanning the Hot Rod site because i just had to replace my McLeod Hydraulic Master cylinder that lost pressure after 2000 miles of driving. They sent me a totally redesigned kit which i just installed. I am having a tough time getting the system bleed, i cant get any pressure. I did a vacuum bleed but no luck after pulling 3 full reservoir out. Just wonder what you ended up using and is it still working

roger1

Discussion Starter · #10 · Mar 1, 2014

I dismantled my Wilwood master and inspected it. The cylinder was scored and it was not rebuildable. The only way the cylinder can get scored is from misalignment. I must have done this during the initial setup and adjusting of the linkage geometry.

I did double check to make sure the final geometry was good and it was perfect. So, I bought another identical Wilwood master and installed it and it's been perfect since. No leaks and it's been over a year.

So, my conclusion is that a lot of care needs to be taken during the initial adjustment of these. I thought I was careful but evidently not enough.

Joer5000

· #11 · Mar 1, 2014

Clutch master cylinder

I going to rip it out and see if it will bench bleed and build pressure so here goes another Saturday

bsagreg

· #12 · Mar 16, 2021

roger1 said:
I've got a '55 Chevy with a T56 and I'm using My Wilwood clutch master cylinder and it is seeping a little.
Probably just a few drops a day underneath car.

The mounting bracket I'm using for the master is angle adjustable so the shaft is perfectly straight into the master coming from the clutch pedal.

I installed this master more than a year ago but haven't even driven the car 200 miles yet. However, it's been seeping like this since not long after I first installed it and got the system bled. Might have been from the very start but went unnoticed for a little while. The reservoir has only dropped about 1/4" over this amount of time and I've never put any more fluid in since I originally bled it.

Other than this little issue my hydraulic clutch system is absolutely perfect. It's the best feeling clutch I've ever owned.

I guess I need to get a rebuild kit for it. I'm just confused why it is giving me any trouble in the first place. Anybody else had this kind of trouble? Are these things prone to leaking?

It's leaking towards the rear of the master where the shaft enters the plunger.

Here's a pic to see how it's mounted on my firewall and it shows my adjustable angle bracket.

Here's what it looks like out of the box that also shows the remote reservoir kit I got with it.

Ii am confused as to how a leaking wilwood master cylinder can be absolutely perfect. I have a wilwood brake single master cylinder that started leaking at about 200 miles and I find it far from perfect.

acgallagher08

· #13 · 22 d ago

I realize it has been a long time since this occurred, but I have the same issue with a wilwood master leaking out the back of the cylinder (where the pushrod and rubber boot connect). It seems to be leaking even when not under pressure since it will simply drip while my car sits without anyone pushing on the pedals.

What did you end up doing to resolve this?

roger1

Discussion Starter · #14 · 22 d ago

Replaced it and it's never had a problem again.
The scoring of the bore happened during my initial setup as mentioned above.

acgallagher08

· #15 · 22 d ago

I have had 3 master cylinders leak out the rear of them (one has not), disassembled and cant find anything wrong with the bore so I am trying to figure out what I could be doing or what others have run into. I may just try a tilton set up.

AutoGear

· #16 · 15 d ago

Make sure that the amount of force generated by your pressure plate can be handled by your hyd system, or you'll blow seals

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