Amazing first go-kart drive until the clutch failed...

[hineas]

I made it up to my brother's house today and we finished the power steering, bled the brakes, inspected everything, then put the vehicle on the ground for the first time in its life.

We started it up and there was a huge leak in the power steering. Fluid went everywhere. Come to find out one of us (my brother) put one of the adapters in backwards and put the flat end into the AM fitting. Oooops. Luckily that was an easy fix.

We cleaned her up and then tried again. The power steering worked great and so we took it on its maiden voyage.

This car is amazing. I had the guts to give it a little throttle (not even 25% throttle). Holy cow it is a responsive, fun car. It was glorious.

My brother lives in a gated community that is a half mile loop. It was perfect for a test run. The car performed admirably-- until it didn't.

The clutch suddenly died and the pedal went to the floor. We ended up pushing the car 0.25 miles and then up his driveway which is a decent sized bill. We checked underneath and hydraulic fluid was leaking from the bottom of the bell housing. It was not transmission fluid, so I suspect it was the throw out bearing. Hopefully it is something as simple as a loose hose connection, but we will see tomorrow. We are going to take apart what we can and take a look.

Any thoughts on how to proceed? Any ideas would be appreciated. II am going to contact BluePrint as well. Wish us luck.

[CraigS]

Not much choice. Unless you find something wrong w/ the fluid hose you have to pull the trans. This is when the removable trans mount is really nice. Glad you have your brother to help. One I helped w/ we pulled the top aluminum from the tunnel and ran a ratchet strap down and round the trans. We adjusted the length so I could stand comfortably w/ my back straight, feet on the seats, and keep tension on the strap. This supported the weight of the trans so the guy on the floor could concentrate on maneuvering it and not worry about it falling on him. Depending on your details you may not be able to get the trans rearward enough for the input shaft to clear the hole in the bell housing. If that happens, remove the bell housing bolts. Tilt the trans down in the front and the bell housing down toward the back, and that will usually let the shaft just barely clear. In that case, we shoved the bell housing back up and held it there by finger installing one of the top bolts. The bell never actually came out of the car since the install was just the reverse.

[rich grsc]

Do you have a hydraulic throw out?

[GoDadGo]

We've seen a couple of fellows where the Hydraulic Throwout Bearing was working fine until the flywheel CUT the line going to it.
You may have had a similar issue, but don't fret because we've all had set backs from time to time.
Congratulations on your first Go-Kart Drive and we look forward to seeing your second.
Good Luck, Happy Wrenching, Don't Throw Tools & Watch Your Pinkies!

Steve

[RJD]

Here's what Steve was talking about - it recently happened to JB in NOVA. Check toward the end of his build thread. See post 344.

https://thefactoryfiveforum.com/showthread.php?35795-JB-in-NOVA-s-MK4-build-9822-has-a-new-color!/page9

[CobraboyDR]

I hear more clutch disaster stories with hydraulic throw-out bearings than good old slave cylinders and traditional forks/bearings.

We had terrible experiences with McLeod TOB's, replacing almost every one when they ultimately failed.

They seem like a good idea but don't seem to execute well.

[hineas]

Thank you everyone for responding so quickly! I have the exact same symptoms as JB Nova's thread, right down to the pink tinged dot 3 fluid.

I am going to go get a transmission jack today and drop the transmission. Once I diagnose the issue I'll contact BluePrint to get it rectified. I have read a few threads on dropping the transmission and it sounds less daunting now. This forum is amazing. I can't imaging building one of these without the forum.

Man, driving the car was amazing yesterday. This car is going to be so much fun!

[hineas]

Once again this forum diagnosed the problem perfectly. One of the hydraulic hoses of the throwout bearing was rubbing on the pressure plate and it wore a hole in the tubing.

We were able to diagnose the problem before dropping the transmission. We removed the cover where the hoses enter the bell housing. We then put my phone in there and using the camera we could see the hole in the tubing. You can see it clearly here:

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We then removed the transmission from the bell housing. The upper bolts that go into the bell housing were an absolute pain to remove because there isn't room, but we got it done. Removing the A-frame transmission mount did give us more room to get those bolts out. It also took various extensions, ratchet sizes, u-joint extensions, etc. We also had to move the tail off the transmission left or right to give us more room.

We also needed to remove the drive shaft and shifter assembly. For anybody who has to do this, the shifter assembly is held on by 6 bolts. The plate has some RTV type sealant and we had to use a pry bar to pop it off. That gave us a lot more room to slide the transmission backwards.

We pulled the transmission back enough to expose the throwout bearing. That gave us enough room to access the hoses on the throwout bearing and remove the one that had the hole. We did not have to completely drop the transmission, which was nice.

150361

150362

150363

Now we just need to wait for a replacement hose (should be under warranty, I assume) or just go to a local hydraulic hose shop and have them make us one. Either way, we found the problem and it turned out not to be as bad of a failure as I initially thought. Sliding the transmission back in will be a pain, but definitely doable.

Thanks again for all the help!!!

[Glen Davis]

Being in the automotive parts business for a lot of years this is not a warranty. A valid warranty is when a properly installed part fails within the manufactured allotted mileage/time frame. The hose rubbing on the pressure plate is an installation issue not failed part issue.

[hineas]

Fair enough, thanks for the letting me know.

I think we will call a local hydraulic hose shop and see if they will make us one. It should be simple, it is just a 9" braided stainless hose with 4AN fittings. I didn't even know there was a store nearby that just specialized in hydraulic hoses!

[M. Townsend]

For a new builder... prior to installing the motor/trans, is there a quick adjustment to make that would prevent the hose from failing?

[first time builder]

If Blueprint install the TOB and bellhouse as part of the package they should get you a new hose, If they dont send a hose they should still be advised of the problem.

[hineas]

For a new builder... prior to installing the motor/trans, is there a quick adjustment to make that would prevent the hose from failing?

I think it happened because the hose is just slightly too long. If you push the hoses back into the transmission all the way it might rub on the pressure plate. Our plan is to pull the hoses out a little then zip tie them so they don't go back into the bell housing. That will pull them away from the pressure plate. I hope that makes sense. They talk about that in the link above where somebody else had the same problem.

[hineas]

If Blueprint install the TOB and bellhouse as part of the package they should get you a new hose, If they dont send a hose they should still be advised of the problem.

Yes, BluePrint installed it. When I read JB's thread, he mentioned that he talked with BluePrint and that McCloed ended up sending him a new hose.

I agree they should know, especially since I'm not the first one with this problem. I am going to contact Jose at BluePrint and talk with him (I was told Johnny moved on to a different job in BluePrint, I was sad to see him go since he had helped me so much). I figured they can at least add a line into their FAQ they send out saying to not push the hose all the way back in.

I'm not sure if we will ask BluePrint for a new hose or not. I think we are going to see if a local hydraulic hose shop can build me one so we can get the car going sooner. A few extra bucks to be able to keep working is worth it since I only have one more weekend to work on the car this summer. But if we can't get the hose tomorrow we will talk with BluePrint to see what our options are.

[rich grsc]

The installer should always check to see that nothing is contacting the pressure plate. That just seems to be common logic

[nucjd19]

Thanks for the M&M ( Morbidity and Mortality) update hineas we can all learn from this situation with the same TOB. I have a BPE 347 with the same TOB as you. I am going to check the hydraulic line that goes into the black plastic covering and ensure the line is retracted posteriorly with no slack that could move forward into the pressure plate. Sorry about the headache but you are helping the community and it is appreciated :)

[chmhasy]

While you are in there, make sure the clutch did not get any hydraulic fluid on it

[hineas]

We checked and it doesn't look like the clutch has hydraulic fluid.

[Fman]

Just a question here not trying to point fingers at anyone but does the internal hydraulic TOB do anything better than external slave? Surely there must be a reason people use them? I cant seem to figure out why someone would install internal TOB where if something goes wrong requires so much more labor to replace. External slave takes 10 minutes to replace if there is ever a problem.

[hineas]

I wish I had an answer to that question, but I just don't know. The reason we have the internal one is because that is what BluePrint is installing in their package. I have to admit that I didn't even know what a throwout bearing was before I started building the car!

That is a really good question and I would like to hear an answer.

[edwardb]

Just a question here not trying to point fingers at anyone but does the internal hydraulic TOB do anything better than external slave? Surely there must be a reason people use them? I cant seem to figure out why someone would install internal TOB where if something goes wrong requires so much more labor to replace. External slave takes 10 minutes to replace if there is ever a problem.


I wish I had an answer to that question, but I just don't know. The reason we have the internal one is because that is what BluePrint is installing in their package. I have to admit that I didn't even know what a throwout bearing was before I started building the car!

That is a really good question and I would like to hear an answer.

Having done both, I'll respond. Certainly don't have all the answers but these are my thoughts for trying one in my Gen 3 Coupe build. The usual hydraulic solution here is the external slave kit from Forte. I've installed several. But IMO it's expensive for what it is. The several hydraulic release bearings out there are cheaper. The hydraulic release bearing is easy to set up compared to the clutch arm version and is self-adjusting. Much like disk brakes. That's a nice advantage since I've found the external slave setup requires a pushrod adjustment usually once a year. Most OE's using manual shift are now using a hydraulic release bearing. I know it's all about cost and they're simpler and no doubt cheaper. But they also do a lot of durability and mileage testing, so they would seem to have merit. With fewer moving parts and potential friction points, I've found the effort is reduced based on the Tilton piece in my Coupe build. Compared to the Forte setup in the Roadster I had previously with everything else the same. When the two were parked side-by-side, I could go back and forth and the difference really was noticeable. The last reason is that when I received the Coupe kit, realized it wouldn't be all that difficult to drop the trans out of the bottom without removing the engine. The different frame, compared to the Roadster, is significant in this regard. One of the big reasons people cite for not using the hydraulic release bearing was in case of failure, the engine/trans had to be pulled. Same as if a mechanical TOB failed, or a clutch replacement. But still seen as an additional risk. While some have pulled Roadster transmissions without also the engine, most agree it's a real pain. Doesn't look so bad for the Coupe. Plus I have a lift. Not wishing I'll ever have to take that step. But decided it was worth the risk so went for it.

That's an edited version of what I wrote almost two years ago when I was wrapping up the Coupe build. Now, two driving seasons (one shortened, one still happening) I'm over 2,000 miles and it's been flawless so far. For the record, mine is a Tilton 6000-Series Hydraulic Release Bearing 60-6104. Since I did mine, there have been three instances on the forum of failures related to the internal setup. Each one was related to the hoses being damaged or cut by moving parts inside the bell housing. Obviously this isn't a failure of the internal setup itself, but rather an installation or parts problem that has to be done properly. Not saying other failure modes aren't possible. Just saying those kind should be preventable. I'd install the same again without hesitation.

[NAZ]

The biggest advantage of the hydraulic T/O bearing style clutch release is packaging. Other than the hoses supporting it, the entire release is contained within the bellhousing. So, the hydraulic T/O has a much smaller footprint and easier to adapt to custom installations with tight space constraints.

As some have experienced, there may be a difference in pedal pressure compared to other release types. That may be a welcome benefit but is not really an advantage and here’s why. The pedal effort is a product of “gain” or mechanical advantage. Like using a longer lever to lift something, it’s all about ratios. Want to make the pedal easier to push, simply use a smaller master cylinder. Any clutch release type can be manipulated to create more or less leverage and the hydraulic releases are the easiest to modify.

But the hydraulic T/O does have disadvantages and are not right for all applications. The biggest drawback is the difficulty servicing it. Compared to other types, it’s a PITA. Some make the argument that it’s no different than changing any style T/O bearing and that is a valid statement. But looking at it from a reliability engineering POV, adding another element inside the bellhousing that will eventually fail increases the chance of a failure requiring pulling the trans, engine, or in my case both.

Some of the other disadvantages of a hydraulic T/O bearing is they are not compatible with all clutch types and are slow to operate. Most won’t ever notice how slow these clutch releases are if they have a street car but if you use your car competitively in a motorsport that requires quick shifting, the hydraulic T/O bearing is going to disappoint you and you will be missing gears more than with a mechanical linkage or cable release.

The hydraulic T/O style release is not bad nor is it the best design for all applications. Like most things, the application, budget, and your knowledge of the system will influence what works best for you.

[hineas]

Thanks for the thoughtful response!

You are right, dropping the transmission was a pain in the roadster, but it was doable. Now that I have done it once it would be much easier if I ever have to do it again. Butto be honest, it only took us a few hours to drop it.

[edwardb]

The biggest advantage of the hydraulic T/O bearing style clutch release is packaging. Other than the hoses supporting it, the entire release is contained within the bellhousing. So, the hydraulic T/O has a much smaller footprint and easier to adapt to custom installations with tight space constraints.

As some have experienced, there may be a difference in pedal pressure compared to other release types. That may be a welcome benefit but is not really an advantage and here’s why. The pedal effort is a product of “gain” or mechanical advantage. Like using a longer lever to lift something, it’s all about ratios. Want to make the pedal easier to push, simply use a smaller master cylinder. Any clutch release type can be manipulated to create more or less leverage and the hydraulic releases are the easiest to modify.

But the hydraulic T/O does have disadvantages and are not right for all applications. The biggest drawback is the difficulty servicing it. Compared to other types, it’s a PITA. Some make the argument that it’s no different than changing any style T/O bearing and that is a valid statement. But looking at it from a reliability engineering POV, adding another element inside the bellhousing that will eventually fail increases the chance of a failure requiring pulling the trans, engine, or in my case both.

Some of the other disadvantages of a hydraulic T/O bearing is they are not compatible with all clutch types and are slow to operate. Most won’t ever notice how slow these clutch releases are if they have a street car but if you use your car competitively in a motorsport that requires quick shifting, the hydraulic T/O bearing is going to disappoint you and you will be missing gears more than with a mechanical linkage or cable release.

The hydraulic T/O style release is not bad nor is it the best design for all applications. Like most things, the application, budget, and your knowledge of the system will influence what works best for you.

You are clearly very knowledgeable (more than me by a lot...) and make great posts. I'm not going to argue but two follow-up comments regarding your response. I don't agree that an external slave setup effort can necessarily be made the same as the internal TOB. Agree a smaller master cylinder reduces effort. But the unchangeable laws of physics still apply. The reason the effort is reduced is because the amount of throw is reduced. Less work = less effort. I had the Roadster referenced above in my post set up with the smallest master cylinder possible (Wilwood 1 inch MC vs the Forte supplied 1-1/8 inch) to still fully release the clutch with the pedal down to the floor. Even smaller would have been less effort, but at the expense of not fully releasing the clutch. Obviously not desirable. This is the setup I was able to compare to the Tilton HRB installation. With the same engine-flywheel-clutch (Coyote, Ford Performance billet, dual friction Centerforce) in both cars. The Tilton HRB is easier to push down and I'm able to confirm it fully releases the clutch. If guys set up their external hydraulic clutch with too large of a MC I agree there's room for improvement. Especially if they're installing stops on the clutch pedal well before its full travel. I recommend a smaller MC in these situations regularly and several have reported it made a difference. But in my experience, with both optimized, the potential is for the internal setup to have less effort.

Regarding slow to operate, you've made this point multiple times. I don't question that it's technically true. But also something I don't ever expect to encounter. I've had builds with a standard cable, the external hydraulic, and now the hydraulic TOB. I've never had any situation where I didn't feel like the clutch actuation kept up. Or even noticed a difference in speed between the types. My driving is 99.9% street cruising, like many on here. And even then I'm pretty conservative. I'm confident this is non-issue for me and I suspect for most others as well who use their cars the same way. I can't speak to a dedicated track machine where every system needs to be optimized.

Everything has trade-offs and this situation is no different. I do agree that a hydraulic TOB failure is more difficult to repair than an external setup. For that reason alone many will decide to stay away, which I understand. But my experience so far has been positive for the reasons I noted. As long as it keeps working (:p) I'm enjoying the advantages. With all due respect to the builders here, it's unfortunate that the recent failures were installation issues. Not with the design itself.

[NAZ]

I too have had very positive experience with several hydraulic T/O release systems. I really don't see disagreement, only different points of emphasis based on our experiences. And a variety of experience is what makes this forum such a great source of valuable information, both experiential and academic based.

Rock on brother, I've learned from your detailed posts and expect more from you that I can use.

[GoDadGo]

I think once you solve your cut line issue you'll be happy with the set-up that you already have in your car.

As for me, I've always preferred a hydraulic clutch setup compared to a cable or mechanical linkage but understand that I only have experience with OEM types...My brother's 2000 C5 Corvette and 1999 Mecham Trans Am run various versions of the T56 that use the hydraulic throwout bearing...My Darkside MK-4 uses a set up from a C-4 Corvette which uses an OEM external slave cylinder but all three vehicles have a buttery smooth clutch feel.

It's just unfortunate that you have to sail these choppy waters, but at least you are dealing with it fairly early in your build.

Good Luck, Happy Wrenching & We Hope The Wind Is At Your Back Regarding This Issue!

[BEAR-AvHistory]

FWIW. On dropping the transmission to service the clutch. Tried an experiment that worked out in my case. Mk-IV, Gen 1 Coyote, TKO-600, 3 Link rear, removable tunnel cover & Harbor Freight manual transmission jack with wheels.

By removing the shifter assembly from the TKO-600 was able to slide the transmission back far enough to change the flywheel & clutch. I use home made dowels from long bolts with their heads cut off that screw into the transmission to bellhousing bolt holes one at a time as I remove the actual transmission/bellhousing bolts.

Install is the reverse line the transmission up with the dowels & slide it back in.

Typically I am working alone so at almost 80 am not into heavy lifting anymore.

[hineas]

Thanks for the great discussion! I always learn a ton on this forum and I enjoy the different perspectives. Comparing driving mine with the hydraulic throwout bearing and my friends with a cable clutch, I really liked the gel of the throwout bearing. I don't have any regrets getting it.

What was also mentioned was the installation issue. We now have the hoses puked back away from the pressure plate so it shouldn't have the same issues.

We were able to buy a hose locally and installed it today. It wasn't too expensive, only $30. That was worth it to be able to keep building on my limited time off.

Kevin, we did something very similar. We ended up taking two of the quick jack bolts that are the sine size and thread. Since these were so long we could thread them into the bottom two holes to help guide the transmission in. It worked really well. The only issue we had was that the splines were binding. We put the driveline back in and turned it so the splines would rotate until the transmission slipped in.

Now that we have done it once, the next time isn't going to be too bad.

We got everything back together now and will take it out for a test drive tonight.

Thanks again for all the help!!!

[hineas]

Just as an update, everything is working well and we have the hose pulled snug so it is away from the pressure plate so this doesn't happen again.