Clutch slave

twobjshelbys · #1 (**permalink**) 10-12-2010, 06:34 AM

My clutch slave cylinder is leaking. I had no clutch, filled and bled, and all the fluid is on the floor. A shop replaced an O-ring but it's dry again after about 100 miles. It's dripping from the bell housing so I'm sure it's the slave. The shop that did the work is 800 miles away so returning there isn't an option.

I obviously can't see what slave is used and don't want to bring it to my friend's shop to disassemble, find out what part it is, order it, ... It'll tie up a spot for a week. I pulled the trans tunnel but can't get to the opening, and the jack stands it's on aren't high enough to drop the trans myself.

The config is the Roush 427IR (351W) with a Quicktime bell housing and Tremec TKO600.

I'm sure the choices for this setup are somewhat limited, and I'd be OK ordering several slaves and returning the others.

One assertion is that my failure is caused by overextending the slave. How can that be verified?

P.S. As much as I'd like, I'm not going to go to an external slave. I got the estimate for that on the repair that failed, and it wasn't worth it.

BT SNAKE · #2 (**permalink**) 10-12-2010, 07:03 AM

Tony,
Does the slave have an adjustable rod on it? You
should be able to control the lengh of engagement by adjustment. It could also be that your slave is mounted to far back and it allows the MC to push fluid past the O ring seal on the slave. If it is this way then the system is stressed to get the clutch disengaged. I would say it would be about 100 miles and it would start to leak.

Hersh

twobjshelbys · #3 (**permalink**) 10-12-2010, 07:28 AM

Quote:

Originally Posted by BT SNAKE

Tony,
Does the slave have an adjustable rod on it? You
should be able to control the lengh of engagement by adjustment. It could also be that your slave is mounted to far back and it allows the MC to push fluid past the O ring seal on the slave. If it is this way then the system is stressed to get the clutch disengaged. I would say it would be about 100 miles and it would start to leak.

Hersh

I have no idea what the setup looks like. I can't see it. That's why I'm looking to get a new one and then deal with the correct adjustments afterwards. The shop didn't say anything about it being so, and I would have expected them to be on the watch for this.

Bob In Ct · #4 (**permalink**) 10-12-2010, 07:31 AM

Tony:
I just went through this on my SPF. Do you have any pictures of the slave area? I've attached a couple of my setup.

Bob

patrickt · #5 (**permalink**) 10-12-2010, 07:35 AM

Quote:

Originally Posted by twobjshelbys

I have no idea what the setup looks like. I can't see it.

If you crawl under your car and look up at the side of your bellhousing, you can't see the clutch fork stickiing out of the hole in the bellhousing and the slave cylinder hooked up to the end of the fork?

strictlypersonl · #6 (**permalink**) 10-12-2010, 08:30 AM

Since it's dripping out of the bellhousing, it's probably a concentric bearing. There's no way to service it without removing the transmission.

To convert to the external slave like Bob in CT, you'll need a new fork, throwout bearing, slave, bracket and perhaps a hose.

Jamo · #7 (**permalink**) 10-12-2010, 09:07 AM

Guys...as noted by strictlypersonl, while Tony's post is slightly vague, it's obvious he's talking about an internal hydraulic setup.

Tony, if you're going to pull everything out to get to it, it's the perfect time to swap out to an external setup...so you won't have to go through this again. I tried living with the internal setups twice before I switched. I even talked Lil Davey Kirkham out of trying to make their own (I was to be the test case).

Whomever put your car together should've put together a limiter for pedal extension for you...you just end up blowing the damn thing apart with too much pressure (it's hydraulics...a little pedal goes a long way). Simple really...just a bolt through a piece of angle to keep the pedal from going too far.

So...anyone with his particular combo (engine/trans) who's using an internal setup needs to weigh in re the proper fitment.

Good luck, Tony.

Chaplain · #8 (**permalink**) 10-12-2010, 10:36 AM

I have a Tilton Hydraulic Throwout Bearing (HTB), which I've had excellent luck with. To install I depth gauged off the transmission mounting surface on the bellhousing to the diaphram levers on the pressure plate. I subtracted .125 from this measurement and used this to set the distance from the face of the THB to the face of the transmission. The routing of the braided lines was really tight so I used a double "U" type bracket to keep the lines away from the spinning pressure plate. It's bolted through the back of the bell housing using a 10-32 allen head bolt and nylock nut on the outside. Access is through the hole a mechanical lever would pass through. I'm using a 3/4" master cylinder and no peddle travel limiter and it doesn't overextend the piston on the THB.

twobjshelbys · #9 (**permalink**) 10-12-2010, 11:48 AM

Quote:

Originally Posted by patrickt

If you crawl under your car and look up at the side of your bellhousing, you can't see the clutch fork stickiing out of the hole in the bellhousing and the slave cylinder hooked up to the end of the fork?

Bob in CT's setup appears to be external... I do like the tie wraps If you can't fix it with duct tape or tie wraps it's not worth fixing.

To summarize this and following posts: It is an internal hydraulic slave. I can't see diddly squat, and noone took any pictures when the work was just done, so I have no idea what I have. The only way to tell is going to be to drop the entire trans and housing and open it up. Once I go this far it's the point of no return - the car is off power, so has to be pushed around by hand and stored inside the shop for a week while I hunt down parts. My mechanic is one of my best friends and I don't want to tie up his shop with dead weight - that's an income producing spot to him. It does happen to him too, so it's not impossible, but with the weather turning to winter here, it's harder to work in.

Changing over to something new will just extend the process. I'm not inclined to spend the time or money to get a new bell housing and external setup. A hydraulic TOB without a separate slave is in the solution space provided it will fit mechanically. Otherwise we'll replace the slave and make sure it stays within mechanical limits.

P.S. Thanks!

patrickt · #10 (**permalink**) 10-12-2010, 11:51 AM

Tony, you do realize that you have to take it all apart to get to the HTOB. There will never be a better time to switch over to an external slave. The cost is certainly under a thousand bucks (parts, I mean).

EDIT -- I just reread your post. Can you give us the number that you refer to in this: " I'm not going to go to an external slave. I got the estimate for that on the repair that failed, and it wasn't worth it."

wolf k · #11 (**permalink**) 10-13-2010, 04:30 PM

http://www.keislerauto.com/ford/ford...ypage_acc.html

I have this setup on my TKO after being disappointed with others. It is an OEM tob used on Corvettes and others, it has internal stop so that it can't be overextended.

WildBill3 · #12 (**permalink**) 10-13-2010, 04:56 PM

?? on the external slave we are trying this also ,we tryed 3/4 and now a 7/8 and we still cant get enough throw on the speedway slave to disengage the clutch on our TKO. sry no help for your slave problem , I liked the put stop on your clutch pedal though

Silverback51 · #13 (**permalink**) 10-13-2010, 05:02 PM

Quote:

Originally Posted by WildBill3

?? on the external slave we are trying this also ,we tryed 3/4 and now a 7/8 and we still cant get enough throw on the speedway slave to disengage the clutch on our TKO.

If you are referring to the slave cylinder size, you are going the wrong way. A smaller diameter will give you a longer stroke.

patrickt · #14 (**permalink**) 10-13-2010, 05:03 PM

Quote:

Originally Posted by wolf k

http://www.keislerauto.com/ford/ford...ypage_acc.html

I have this setup on my TKO after being disappointed with others. It is an OEM tob used on Corvettes and others, it has internal stop so that it can't be overextended.

That's pretty nice alright -- but I don't think he wants to drop $650 in parts (or else he would go to an external). Is the current crop of ERA FIAs still limited to HTOBs?

Silverback51 · #15 (**permalink**) 10-13-2010, 05:04 PM

One thing to remember about hydraulics. No matter what you do, at some point they will leak.

I would much rather have an external slave cylinder that I can rebuild or replace easily, than a hydraulic throw out bearing that I have to remove the transmission to replace. Plus, if it's leaking, chances are your clutch will be toast also.

twobjshelbys · #16 (**permalink**) 10-13-2010, 05:16 PM

Quote:

Originally Posted by patrickt

That's pretty nice alright -- but I don't think he wants to drop $650 in parts (or else he would go to an external). Is the current crop of ERA FIAs still limited to HTOBs?

I would also be concerned about it fitting in the allocated space. It is a little pricey though.

WildBill3 · #17 (**permalink**) 10-13-2010, 06:26 PM

sry for that I was refering to the Master cyl.

WildBill3 · #18 (**permalink**) 10-14-2010, 04:37 AM

We had a 3/4 inch master cyl.on with about an inch of movement now thers a 7/8 master cyl on and we still dont get enough movement for clutch engagement......
We ran a slave in the bell once and it preformed well but i can see this happening again in your situation without a stop .As soon as we figure out ours we will put a stop on our pedal to

wolf k · #19 (**permalink**) 10-14-2010, 06:08 AM

Tony, I am sure they would just sell you the TOB, and it uses a 3/4 bore master cylinder which you already have. If your asking for a reliable internal slave throw out bearing, this would be it. Good luck, Wolfgang

tkb289 · #20 (**permalink**) 10-14-2010, 06:43 AM

Quote:

Originally Posted by patrickt

... Is the current crop of ERA FIAs still limited to HTOBs?

(Tony ... not to hijack the thread too much

... )

Patrick,

Is there a limitation with the FIA that would preclude use of an external slave cylinder ?

In reading the FIA manual (pg 31) ... for easiest installation with a SBF, ERA recommends the following:

Concentric TOB (internal) for T-5, Tremec
External slave cyl for Top-loader, Richmond Gear 5 sp

On page 32 it's noted that some clutch/transmission setups work better with a concentric TOB.

So, I will need to check with Bob to see if it will fit, but for my car I am looking at the TKO 600, QT Bell Housing and external slave cylinder. I certainly respect ERA's recommendations as they know what works best for their cars.

Any thoughts?

Thanks