hydraulic throw-out bearings

[niles]

I'm having to convert my engine over to a HTOB.
Can anyone comment on the merits, experience, etc on the McLoed, Tilton or Howe? These seem to be the popular choices.
Would appreicate any experiences; since this is a engine pull issue, I would like to get it right the first time!!

gn

[Mr.Fixit]

Why do you have to convert?

I don't recommend them unless there is no other viable option for your car. As soon as the O-rings leak, you have to pull the tranny (or motor) to replace the seals. You will need to replace the O-rings after some time, that's why they give you the first replacement set in the box with the TO. If there is any room at all to install a slave cyl and use a fork, DO IT. When that needs service, it is all external.

[ENTDOC]

Grover,I have a new in box McCleod htob. I ended up using a slave.The bearing is easy to install with a few measurments taken.The key is to adjust the pedal travel so as not to over throw the bearing. chuck

[Cobra #42]

Don't use an internal TO bearing !!!!! Regardless of make, they are all a royal pain in the rear. They always leak and a pulling the trans is a pain. Just say NO to internal TO bearings. Thanks, db

[Jack21]

Listen to the man. It ain't worth the hassle. Go external, or go cable. Exhaust every cable clutch install possibility before screwing with hydraulics.

[KobraKarl]

I'll ditto that for the 50 or so guys ive read about in the last 4 years who were spending a lot of time bench pressing top loaders
between crying jags.

KK

[Cobranut]

gn,

I had a McLeod unit and it leaked the first time at about 350 miles.
I pulled the trans and replaced the seals and it lasted till about 1200 mi.
This time an o-ring on one of the banjo joints let go.
I pulled the tranny again and converted to an external slave setup.
This required going to a larger M/C to get enough travel, which in turn resulted in a REALLY firm clutch pedal, but it works great. (And my left leg's getting stronger).

Stay with an external slave if possible.

[Rick Bagley]

All I can say is the HTO bearing gets a bad rap!!! I know of at least 7 in FE cars that were put in and no problem from 7 years ago to the present. It just takes some good measuring and installing it correct the first time. I am using a McLeod HTO bearing and clutch and absolutely love it. You must use DOT 3 fluid in these because of the type o ring seals. Like everything else your mechanical ability will dictate the results. The old Bull Sh#@ that they wont work is excactly that , Bull Sh#@.

[rdorman]

I second the many motions AGAINST a hydraulic throw out bearing. The standard throwout bearing seems to last for ever where the the hydraulics, internal or external, seem to require frequent maintenance.

Hydraulic throwout bearing DO work, but have the same service issues that an external unit does and do you want to pull the tranny every time to service it? Your choice!

Rick

[rdorman]

http://www.clubcobra.com/t42031.html

[Back in Black]

Had the o-rings blow out twice (centerforce 2 dual friction clutch and wilwood master cylinder, I am not sure that the hydraulic slave was wilwood or centerforce, but I am guessing it was centerforce)

Here's the two big problems, and my solution, if you want a hydraulic clutch.. I can tell you that with the 12 inch McCleod disc we are converting to, (the original centerforce was 10 inches ) and the HEAVY three pronged spring powered pressure plate, nothing but a hydraulic would be realistic to drive in traffic. Even if you're Arnie .. oops, better not start that again

SO:
1) You MUST have a physical travel stop. I am going to paste a recent e-mail response to a CC member here explaining what we are doing to my car. I designed the stop myself from off the shelf components. It has a plate mounted near the master
clutch cylinder, on the front side of the firewall... a hole is drilled thru the center, a nut is in the center, welded on, it's 3 x 3 inches...we powdercoated this item... a piece of 1/2" ss threaded rod will run thru this, an aircraft locknut to restrain it down there... of course it shoots thru the firewall and at the other end we are using a poly body buffer, like the trick hard urethane mounts now becoming popular...the one I am using is from Energy Suspension, it looks like a 2 inch wide black, flattened gumdrop, part number 9.9116G. The pedal arm will stop on this, and it will be fully adjustable. As to travel, I am going to set it
3/4 of an inch (max) past disengagement...

2) DO NOT use the o-ring hydraulic clutch attachment to the slave cylinder!!! I repeat!...NO! use a 90 degree AN fitting and the same ss lines as you had planned. The o-rings WILL blow out and you'll be where I am, now for the 2nd time in 3,000 miles. The first time they blew before the car was even delivered! Use AN fittings, this is
what McCleod advised.. there's plenty of flexibility in the two lines.... it's a "hard" (meaning durable and tough) installation


I will try to post pics in my gallery as we do this work, or here on this thread if I can find it again. As to the measurement thing, McCleod will specifically set you up with the right internal slave if you measure correctly. I have some great pros doing this part, althought they have been cool about letting me use the shop to trick my car out and fix several manufacturer "defects" such as replacing the joke of an oil cooler (the stupic 2 tube type, was hidden down on the frame by west coast in contradiction to my stated wishes, (it was totally inadequate and took quite a beating down there) what I wanted was what I now have, a front mounted 900 cfm blower unit from Perma Cool, 15 wide x 10 high, manual dash switch with fused relay. In addition my radiator had the metal thru rods for fan mounting, do NOT use these! use the cable tie type with sponge buffers
My lower two bolts had fallen out, so it looked normal when sitting, except the tiny bolts were not there...but when I got on it , the fan became a tilt-away model

Time to head over there and finish my part of the work today.

[Back in Black]

The reason the o-rings blow out down there is overtravel on the master cylinder causing excessive pressure. That's all there is to it. Install a physical travel stop !

[Mr.Fixit]

Even without overextending the TO, the O-rings just don't last all that long. Especially if the driver like to do things such as sit at a red light with the tranny in gear and the clutch pushed in for extended amounts of time. They are very easy to set-up, but a real pain to service.

[trularin]

I would agree with the 'slave' cylinder notion.

Pulling the trans to fix a problem the designer knows exists, sucks.

There are so many slaves out on the market. A datsun 1200 cylinder is great. all you need to do is fashion a bracket and bolt it on. If it ever leaks, get a new one and move on.

Just a thought

[Dan Stryffeler]

I've had two McLeod units installed, both blew out at the banjo fittings - not - the 'o'-rings. I understand that they have redesigned the unit in the last year to solve the problem and were offering rebates if you sent them your old unit in exchange.

I switched to an external slave unit, no muss, no fuss.

- Dan

[rdorman]

While set up correctly, they can have there advantages. But as you can see..............

Seems to me there is issue with some diaprahm type pressure plates and if not adjusted correctly, or you have some one that rests the foot on the clutch, it can and probably will fail early.

Rick

[John S Peterson]

I also had my problems with that tob, but once I changed the banjo fittings to A/N and dropped master cyl size down to 5/8" and added a pedal stop, it has been trouble fee for the last 4000 miles. These problems can be solved, and this forum is a great resource of info from a group of very smart men, but don't let that sway your decision on weather to use a htob. They do make life easier if you do it right.....John

[427sharpe]

I use the McLeod tob, and had the same problems as noted elsewhere, but found a simple fix. I noticed that the orings inside the tob did not fail, but the orings McLeod used on the banjo fittings where the source of the problems. After having a couple of failures, I decided that the original design was at fault so I combed a partshouse bin and found some orings that were rubber and brake fluid resistant and used these to replace the gum type rings that McLeod uses. No problems since the fix, well over 7000 miles ago and I use a very strong clutch set up. In spite of all of this, I would definitely recommend an external unit IF POSSIBLE, as they are one heck of a lot easier to service in case of trouble!

[RobbMc]

I ran a Tilton HTOB on my pro-street car for five years and about 10,000 miles with no problems.

I used a pedal stop and followed the instructions.

The Tilton design uses a dual durometer quad seal rather than an o-ring. The issue with the banjo fittings was solved at Tilton ten years ago, at least in the design area (there can always be QC problems).

I used a 3/4" m/c and a 6 to 1 pedal ratio. The pedal effort was half of the mechanical linkage a very smooth.

[Mr.Fixit]

The tilton is better than the McLeod, but both are a pain if service becomes required.