Wilwood Master Cylinder Premature Failure - hydraulic clutch

[FF33rod]

Looking to hear if anyone else has seen or heard of premature wear/failure of a Wilwood Master Cylinder?

This is a '33 setup but pretty sure it applies to anyone that has a hydraulic clutch setup. The complete setup is wilwood - reverse swing mount brake and clutch pedal assembly with mount locations for dual master brakes and a clutch master. Therefore, all geometries should be correct. This is the master style: https://wilwood.com/MasterCylinders/...ter%20Cylinder

Long story short, at 1800 miles the clutch master went on my way to the first long distance car show. One side of the piston had worn enough that the seals no longer worked properly, as soon as any pressure built it blew past the seals due to the wear.

I had to work with a local shop in the city I was in to replace the cylinder and the interesting part is that he said this is the 3rd Wilwood master that he's seen fail in the same way in the last 2 years. This seems really weird, is anyone else experiencing or seeing something similar?

Steve

P.S. I will be reaching out to Wilwood to see what they say but would like to hear from the FFR community as well

[MVTV]

I went through it the hard way as well. ~250 miles and a leak started. Found out this is actually somewhat common. Wilwood will say the angle is off causing the pistons to leak but it can’t be if you’re using a Wilwood pedal box (at least I believe). Wilwood sent me (and others) new master cylinders. They make you send in yours for inspection then send you a new one. About a month long. Many have gone with Tilton cylinders as they are supposedly better. I stuck with Wilwood.

[edwardb]

Hear about failures of those occasionally. But not sure it's a huge issue. Fortunately, neither the rebuild kit or all new MC is all that expensive. Had to rebuild one on my Coupe due to a defective O-ring on the piston. Wilwood Master Cylinder Rebuild Kit 260-10514 is for the .75 MC. Includes all the parts except the housing itself. < $30. All new MC is < $100. Not sure what Wilwood's position on it will be, since their literature seems to go of its way to say no warranty. I've also heard of some using Tilton parts. But no personal experience and not sure if they're bolt-in compatible.

[FF33rod]

Thanks guys. True, the parts aren't expensive, that's not the issue. The big issue is a) failure in the middle of no where and b) trying to replace this sucker in a gen 1 hot rod with the body on is a nightmare! I was a bit lucky in my choice of AC vent location in the dash - disconnected the hose, took out the vent and was able to access the hard line to the master which helped a bit....

Another Wilwood went in but if it fails again I'll be looking at alternatives

Steve

[Fman]

I had the same failure at around 2000 miles, started leaking and almost left me stranded for the tow of shame but fortunately I was able to just make it home. Wildwood ended up replacing it for me under warranty after I sent the old one in. They claimed it was side loaded but had no explanation how this happened with there own pedal box. There are no side to side adjustments (that I am aware of). It was a complete PIA to swap out on a roadster with the body on, knock on wood right at 2000 miles now on the new one and so far it is holding up. If this one ends up failing I will try the Tilton, I have heard they are better quality.

If you ever feel your clutch pedal get a little "slippery" you have a leak, I had noticed this a couple drives prior to almost not making it home. Lesson learned for me.

[Caddy Dad]

I have 3 Wilwood master cylinders on my MK IV (front rear brakes, clutch) all 0.75 diameter. The rear master cylinder developed a leak at about ~2200 miles. Wilwood said no warranty and must have been side loaded. I'm using their setup so almost impossible to side load it. FFR replaced it for free. If the clutch master cylinder develops a leak, it'll be a real PIA to replace that!

[RBachman]

The Wildwood warranty can be reduce to these three words: "PAY UP SUCKER!"

As a licensed engineer, I am not a fan of the Wilwoods for this very "warranty" reason and will always strongly recommend against them. If they themselves have no confidence in their products to function, or even come out of the box without manufacturing defects, why should we? No warranty also means there is no incentive to produce a decent product. Wilwoods "policy" is that once purchased it is yours. If you open the brand new box and it's busted, it's all on you. Obvious manufacturing problems? That's all on you also.

Considering that Wilwood themselves have ZERO confidence in their own products (as is clearly shown by their "warranty") why should anyone else trust them? No one wants to deal with a company who's warranty is a big "FU!" This also leads into the subject of safety. Brakes should work, but Wildwood policy doesn't seem to reflect this. In fact, working brakes and viable/reliable components isn't even in the realm of discussion with them. Professionally I strongly recommend against them. There are better choices with companies that are not ashamed to stand behind their customers when there is an issue, and do not leave their customers abused and out of pocket with Wildwood manufacturing and design failures.

[MyBucketList]

Looking to hear if anyone else has seen or heard of premature wear/failure of a Wilwood Master Cylinder?

This is a '33 setup but pretty sure it applies to anyone that has a hydraulic clutch setup. The complete setup is wilwood - reverse swing mount brake and clutch pedal assembly with mount locations for dual master brakes and a clutch master. Therefore, all geometries should be correct. This is the master style: https://wilwood.com/MasterCylinders/...ter%20Cylinder

Long story short, at 1800 miles the clutch master went on my way to the first long distance car show. One side of the piston had worn enough that the seals no longer worked properly, as soon as any pressure built it blew past the seals due to the wear.

I had to work with a local shop in the city I was in to replace the cylinder and the interesting part is that he said this is the 3rd Wilwood master that he's seen fail in the same way in the last 2 years. This seems really weird, is anyone else experiencing or seeing something similar?

Steve

P.S. I will be reaching out to Wilwood to see what they say but would like to hear from the FFR community as well

I now it has been a while since this post. I ran across this in searching for similar experience to my recent issue. Again... same Wilwood Brake Master cylinder being used for a clutch cylinder. I am running the kit supplied Wilwood pedal box, so alignment/side loading should not be an issue. Eerily, my cylinder also failed around ~1800 miles. Pedal started getting soft on a drive home and ended up going all the way to the floor. System lost all pressure and I had no fluid leaks. Luckily, I was not far from home. I do have an extra cylinder from upgrading to power brakes so outside of being a pain to change (and a towing bill), this was not catastrophic.

I was wondering if the fluid was getting overheated with the line running through the back side of the engine compartment and down into the tunnel. Tough to verify though. I did read that high fluid temps can cause seal degradation and premature failure. Don't know whether that was from a reputable source or not, so I am doing some insulation wrap wrap to reduce the risk as a possible cause as I put it back together. Longer term, I am just going to keep and eye on it and hope the second cylinder has a longer effective life.

How has you replacement been performing? Any follow up issues?

[MyBucketList]

The Wildwood warranty can be reduce to these three words: "PAY UP SUCKER!"

As a licensed engineer, I am not a fan of the Wilwoods for this very "warranty" reason and will always strongly recommend against them. If they themselves have no confidence in their products to function, or even come out of the box without manufacturing defects, why should we? No warranty also means there is no incentive to produce a decent product. Wilwoods "policy" is that once purchased it is yours. If you open the brand new box and it's busted, it's all on you. Obvious manufacturing problems? That's all on you also.

Considering that Wilwood themselves have ZERO confidence in their own products (as is clearly shown by their "warranty") why should anyone else trust them? No one wants to deal with a company who's warranty is a big "FU!" This also leads into the subject of safety. Brakes should work, but Wildwood policy doesn't seem to reflect this. In fact, working brakes and viable/reliable components isn't even in the realm of discussion with them. Professionally I strongly recommend against them. There are better choices with companies that are not ashamed to stand behind their customers when there is an issue, and do not leave their customers abused and out of pocket with Wildwood manufacturing and design failures.

Any direct recommendations for a better cylinder that is a direct replacement to fit the Wilwood pedal box? Interested, having trouble finding something so far.

[F500guy]

I just ordered 3 tilton 75 series to replace mine before I button up the driver foot box.

[Alec]

I now it has been a while since this post. I ran across this in searching for similar experience to my recent issue. Again... same Wilwood Brake Master cylinder being used for a clutch cylinder. I am running the kit supplied Wilwood pedal box, so alignment/side loading should not be an issue. Eerily, my cylinder also failed around ~1800 miles. Pedal started getting soft on a drive home and ended up going all the way to the floor. System lost all pressure and I had no fluid leaks. Luckily, I was not far from home. I do have an extra cylinder from upgrading to power brakes so outside of being a pain to change (and a towing bill), this was not catastrophic.

I was wondering if the fluid was getting overheated with the line running through the back side of the engine compartment and down into the tunnel. Tough to verify though. I did read that high fluid temps can cause seal degradation and premature failure. Don't know whether that was from a reputable source or not, so I am doing some insulation wrap wrap to reduce the risk as a possible cause as I put it back together. Longer term, I am just going to keep and eye on it and hope the second cylinder has a longer effective life.

How has you replacement been performing? Any follow up issues?

I just had my wilwood .75 rear brake MC fail at 2000 miles. I replaced it on my own dime and sent the failed one to wilwood with an RMA several weeks ago. So far they haven't reached back out. This isn't nearly as rare as it SHOULD BE! And they already told me that it was likely side-loading (it wasn't) and that since I bought the replacement from Summit (so that I could get back on the road quickly), they wouldn't reimburse me but just rebuild it and send it back to me. Thanks, but I no longer need it, rather have my $100 back.

[MyBucketList]

I just ordered 3 tilton 75 series to replace mine before I button up the driver foot box.

I went ahead and ordered one as well off Amazon. Should be here Friday so I can get the replacement in this weekend and be back up and running.

I just don't trust the Wilwood at this point after reading all the history. Glad I upgraded to a power brake system that did not use the other Wilwood masters there. No clutch is annoying. No brakes... well, a bit more of an issue.

Thanks again. Once again the forum comes through. This community is a God send.

Happy motoring!

[burchfieldb]

Based on this thread, I will likley be proactive and replace mine before they even hit the road. The first set was bad out of the box for me, but FFR replaced them since I had just got them.

20221002_132538.jpg

[FF33rod]

I just ordered 3 tilton 75 series to replace mine before I button up the driver foot box.

Yes, the Tilton ones were the only likely compatible ones I could find. My replacement Wilwood is still functioning 2 yrs later BUT its the pedal is starting to feel a little different so I'm wary....

Steve

[Alec]

I just had my wilwood .75 rear brake MC fail at 2000 miles. I replaced it on my own dime and sent the failed one to wilwood with an RMA several weeks ago. So far they haven't reached back out. This isn't nearly as rare as it SHOULD BE! And they already told me that it was likely side-loading (it wasn't) and that since I bought the replacement from Summit (so that I could get back on the road quickly), they wouldn't reimburse me but just rebuild it and send it back to me. Thanks, but I no longer need it, rather have my $100 back.

- UPDATE -

I received a (my) rebuilt MC from Wilwood Engineering after about 5-6 weeks (See my previous post quoted above for a recap).
It came with no communication, meaning:
*No acknowledgment that it was manufacturer error, or apology/acknowledgment that I could have died having lost brakes while driving.
*No indication that it failed due to side loading which is what they said was likely prior to me sending it in. BTW I followed all instructions and those pushrods were parallel to each other and straight-on to the MC body.
*No offer to reimburse the $110 I spent to get a replacement quickly at Summit.

Occasional part failure is fine, but perhaps this is a bit too common? Anecdotal, of course, with these posts on FFR forums. But I'm most concerned about the lack of transparency on what caused the failure, the total lack of communication from them, and their unwillingness to make it right by reimbursing me. They could have just kept the MC, I didn't want it back. If I had followed their instructions to mail it in for diagnosis and potential rebuild, I would have had my car off the road for 6 weeks at least while I waited on them. Nope.