Hydraulic throw-out bearing failure??? BRAND NEW!!!

So I bought a Fiat 500 with a bad throw-out bearing and after install the damn thing is spraying all inside the bellhousing.

I didn't pressurize the system until it was all bolted in place.

I used a vaccum bleeder before applying pedal pressure to the system. It started to get pedal feel after a few minutes and then I heard a gurgle. Looked under the car to find a puddle.

I don't know if it cracked when installing it or it was already damaged?

Any installation tips for these that I should know? Seems like a pretty simple system other than the bleeding hose setup. Just don't want to pull it out and have the same thing happen again due to error.

Ug. That's the worst.

I had a jeep xj that I replaced like 4-5 hydraulic slaves on (I got pretty good at dropping the trans). Parts store parts sucked, even the dealership part I bought after the 4th or whatever quickly failed. 

The first one was basically failed right out of the box, or failed within 25 clutch swings iirc.

All that said, I think in my case other than the first one, my issue was actually failed trans mounts letting the trans flip around and then putting too much movement strain on the lines and the o-rings. Can't confirm because I didn't think that up until long after I got rid of the Jeep lol.

All I can say is I don't think it is you. Unfortunately.

In reply to Robbie (Forum Supporter) :

Dang, I think I would have set the Jeep on fire after the second one failed. Really hoping this doesn't happen again cause the room to install the trans isn't exactly spacious, but also a E36 M3ty game of Tetris to get it in.

I'm curious what brand TOB you used .. OEM, aftermarket, ???

In reply to einy (Forum Supporter) :

It's a Sachs clutch kit but not sure who manufactures the part in the kit. PP and disc both have Sachs stamps. It didn't have Valeo stamped on it like the OEM does which LUK also sells. I've had really good luck with Sachs stuff so I am quite surprised it failed. Maybe it was slightly damaged in shipping since it's paired with the pressure plate/clutch disc all in the same box? I recall thinking it wasn't packaged well but didn't see any obvious signs of damage. It was a drop ship from Turn 14 that was ordered through TH Motorsports.

It's one thing if it's an OEM design, but I don't understand why people use these on race cars - you have to pull the damn engine or gearbox to fix it! At least if it's external you can just bolt in a new one and go....

In reply to MiniDave :

Agreed. External slave would have been delightful. Easy fix from the get go because I don't think the trans would have required pulling otherwise.

MiniDave said:

It's one thing if it's an OEM design, but I don't understand why people use these on race cars - you have to pull the damn engine or gearbox to fix it! At least if it's external you can just bolt in a new one and go....

I take it you've never had pivot balls break or forks flex and crack, even after reinforcing both of them.

You have to pull the trans to fix those, too, and despite having a chassis known for its crappy clutch hydraulics (first generation RX-7) I have had more ball and fork failures than slave cylinder failures.

FWIW, I have done one Mini clutch, an R50, and I was only replacing the clutch while I was in there to repair the broken clutch fork.  I would have replaced it but the failure was so common that they were on intergalactic backorder.

On the Panda, Suzuki SX4 I remember taking great care to not crack the plastic housing.  The interwebs told me to be careful as it can crack while connecting the hose and the hose can also crack.

In your case, probably a defective part.

Pete. (l33t FS) said:

MiniDave said:

It's one thing if it's an OEM design, but I don't understand why people use these on race cars - you have to pull the damn engine or gearbox to fix it! At least if it's external you can just bolt in a new one and go....

I take it you've never had pivot balls break or forks flex and crack, even after reinforcing both of them.

You have to pull the trans to fix those, too, and despite having a chassis known for its crappy clutch hydraulics (first generation RX-7) I have had more ball and fork failures than slave cylinder failures.

 

FWIW, I have done one Mini clutch, an R50, and I was only replacing the clutch while I was in there to repair the broken clutch fork.  I would have replaced it but the failure was so common that they were on intergalactic backorder.

That was my thought as well.  I have had more forks broken / displaced and bearing failures than I have ever had with HTOB.

I see the use case for both.  I still chose HTOB for my racecar and for my project car.

I am averse to HTOBs if there is any reasonable alternative.  This issue comes up all the time in the MG world where engine transplants are common. My rationale is that if you can possibly fit an external slave, do it. Even if the chance of an HTOB failure is small, it is still possible and you are looking at engine out job to fix it as opposed to a sub $10 charge for a new rubber kit for an external one and half an hour under the car.

This is a simple bracket I had machined up tp put a GM V6 in an MG.  Cost me a case of beer to a machinist friend and a few minutes for me to spec out a cylinder from something else with the right bore etc.

It fit just fine and I sourced an early 90s Camaro bell housing to take it.

One of the guys criticized me for doing extra work to have an external slave put the HTOB in his MGB swap - and guess what?  It failed and was an engine out job.

Maybe it is something about American designs but we have never had a failure of a pivot or release fork on our British cars, the only 'weak' point is on some that use a carbon faced release bearing - they are not suitable for dim bulb drivers that like to sit with the clutch in at lights or ride the clutch at other times.  With an owner that knows how to drive a manual trans properly they can last 100,000 miles

I have never had a clutch fork fail, no. So that limits my experience I guess. I'm thinking of friends with Sprite racecars, it's not funny how many of the center mount release setups have failed, sometimes soaking the clutch disc and all requiring removal of the engine to repair.

I've had a few forks bent as well as failed bearings that required trans removal. Also pivots snapping. Forgot about those.

So far the ratio of internal hydraulic I've had fail is pretty small since this is the first I've dealt with. With that said my sample size is probably skewed.

In summary, I'm just bummed I need to take the trans back out and I've decided to not blame the system but chalk it up to bad luck. The new part has been ordered, I just hope it's in stock and ships quickly.

Really common for the connection points to leak on all Fiat slaves.  It's tough to see in the video where exactly it's coming from but it's usually the feed that leaks. 

In reply to RonnieFnD :

This appears to be all inside the bellhousing at a couple different places. The metal clip where the L-bow juntion is and what I assume to be a crack or hole above it. I have zero leakage at the connection point where the line clips in. I do plan to replace those o-rings this time around though.

I'll know more soon as this evening it will hopefully be back on the ground for full inspection. Probably should have waited on ordering a new part but I'm not a patient person when it comes to getting things fixed.

Is it possible to bench test these before putting the transmission back in the car? I am thinking hooking it up to the car, come up with a way to limit its travel and pressing the clutch. 

In reply to Slippery :

I really wanted to do that with the new one, but the instructions from Sachs deliberately states to only ever pressurize the system when in situ. Doing it outside of those parameters may cause damage to the internal seal. The instructions also say to not depress manually for the same reason. I'm surprised the seal is that delicate considering it's use case.

captainawesome said:

In reply to Slippery :

I really wanted to do that with the new one, but the instructions from Sachs deliberately states to only ever pressurize the system when in situ. Doing it outside of those parameters may cause damage to the internal seal. The instructions also say to not depress manually for the same reason. I'm surprised the seal is that delicate considering it's use case.

 

I suspect they just don't want it to over extend. Like if you press on the brakes with no pad or disk in the caliper and pop the pistons out. 

Robbie (Forum Supporter) said:

captainawesome said:

In reply to Slippery :

I really wanted to do that with the new one, but the instructions from Sachs deliberately states to only ever pressurize the system when in situ. Doing it outside of those parameters may cause damage to the internal seal. The instructions also say to not depress manually for the same reason. I'm surprised the seal is that delicate considering it's use case.

 

I suspect they just don't want it to over extend. Like if you press on the brakes with no pad or disk in the caliper and pop the pistons out. 

That was my thought. A thread rod with two thick washers or piece of aluminum on each end/nut should take care of the travel. As a matter of fact, I would make it so that it almost does not move at all ... just pressurizes the system.

In reply to Robbie (Forum Supporter) :

That make sense. I may see if I can limit the throw for testing somehow. Luckily I have the failed one I replaced and now this one to tinker with before trying the new one.

In reply to Slippery :

I like that idea. I had a way more complicated setup in mind that I think would have been a nightmare.

Unfortunately I just got refunded for the new part. I've read there are shortages for these so I may have to opt for the $50 offbrand one on ebay.

captainawesome said:

In reply to Slippery :

I like that idea. I had a way more complicated setup in mind that I think would have been a nightmare.

Lol, I always over-complicate stuff. If you need anything machined let me know, I'll be glad to help.

In reply to Slippery :

I think some ball joint press pieces plus the threaded rod should do the trick nicely.

Problem solved!

Pulled the trans and no obvious signs of cracking or leak points but based on the video I knew that the part where the elbow is pinned was pushing fluid out.

So I took a bearing tool cup set with the threaded rod to hold the bearing tight and not allow it to move. This was suggested above and it worked perfect. I didn't take video but it was gushing right out of that elbow joint. A lot of fluid.

I disconnected it and decided to dissect my old one that this one was supposed to replace. A pair of pliers pulled the metal clip and voila an elbow with an o-ring.

When I started to pull the clip on the new one that was leaking, the elbow was SUPER loose. It wiggles quite a bit which obviously explains the lack of sealing. On a whim I decided to swap elbows and surprisingly enough it's a SNUG fit! So I stole the new o-ring and installed the old elbow into the new bearing.

I quickly set it up with the cups and thread to test it in the car. As soon as I hooked up the bleeder I knew it was fixed. On the previous install the pump wouldn't hold vacuum. I thought maybe I was screwing up the setup or it was just the way the bleeder is on this type of system. With the hodge podge setup it immediately held vacuum and even better pulled bubbles out like a treat. As soon as I tried to press the pedal it was rock solid and held pressure without a single drip. With the threaded rod keeping it from extending it couldn't move so the solid pedal makes sense.

I danced a little jig and started to clean everything up. It's going back in the car tomorrow with this setup. I have no doubt the problem was a poor fitting elbow on the Sachs part.