Hydraulic release bearing

[holywood3645]

What is the current opinion on using a hydraulic release bearing and removing the OEM setup.
Does anyone supply a good option?
James

[nigelrbfurness]

I think the argument against has aways been accessibility. In order to repair or replace a concentric cylinder and release bearing inside the bellhousing on an Elan, you have to remove the engine first. The original setup may not have a long life before attention is required, but replacing the slave cylinder takes minutes. The release bearing itself is not a well-known failure point, indeed in nearly 50 years of Elan ownership I've never found one in unusable condition and only replace them as a "might as well" item whilst tge engine is out.

[holywood3645]

It’s actually for a MK1 escort application.

[Elanintheforest]

You would still need to get the engine out with the Escort James unless you have a modified transmission tunnel...the engine and box are a very tight fit for the Twincam and BDA.

I really don't see any advantage in the concentric slave either, other that a very slightly lighter clutch. But they are incredibly light on the Twincam / BDA application. I also don't trust aftermarket stuff which hasn't been tested and proven as well as OEM, but the bottom line is that the original setup works so well.

I rebuilt the slave on my Elan in 2 hours, including getting it out and back in. And that had lasted 30 years!

Mark

[2cams70]

There's nothing wrong with the standard setup. Only weak point is the clutch fork which was originally designed for grandma's Mk1 Cortina. They can crack around the ball pivot area. The solution is to use a heavy duty fork from Burtons.

[prezoom]

I have both types of clutch release configurations. The standard external slave on the S2 and a concentric Contour/Mondaeo release on the Zetec Plus2. Both have their advantages and disadvantages. Heat being the enemy of the external, along with the PITA bleeding issue. The external also takes away valuable room for the exhaust system. The setup process for the concentric can/was a bit problematic in its mounting and getting it positioned correctly for complete release at a comfortable foot depression height. I solved the mounting issue by making a new bearing retainer that replaces the original, to which the bearing release is mounted. Another advantage on the Plus2 is, it is very easy to route the bleed nipple up between the brake and clutch masters. This allows gravity to do the bleeding for you. Just fill the master with the bleed nipple open and the fluid in the system will seek a common level with the master. No crawling under or pumping action required. Removal of the retaining ring on the bell housing opened up the area for exhaust system, which allowed for the complete system be tucked up above the bottom of the chassis rails, until the single pipe dips beneath the gearbox. The down pipes are now routed in front of the engine mount for additional clearance for the larger diameter tubing, and can be removed without all the gymnastics needed for the original system. However, getting there is a thrash. Since all new manual transmission cars are now equipped with concentric slaves, they should last a lifetime.

I have sleeved multiples of the original style slaves with stainless over the years, rather than purchase what is now advertised as new, complete with inclusions, which leaked worse that the corroded ones removed. All of which, have performed without any problems. My slaves are connected by a flexible AN style line, and are, bled before installation by raising the slave to expel any air. A piston blocking jig was make to prevent expulsion of the piston during bleeding. Both systems work almost indentically, in regards to foot pressure and release points.

One issue I encountered during the Plus2 installation, and the switch between the semi close and the close ratio gear boxes, was the difference between the bearing retainers. The are not interchangeable. And a new one was needed for the close ratio gearbox.

[gjz30075]

The setup process for the concentric can/was a bit problematic in its mounting and getting it positioned correctly for complete release at a comfortable foot depression height. I solved the mounting issue by making a new bearing retainer that replaces the original, to which the bearing release is mounted.

Rob, did you do this exercise with the engine and gearbox out of the car? Do you have a 'remote' pedal
box to determine the engagement/disengagement height?

[LI-599]

I might have missed all the the reasons for anyone wanting to replace the original clutch slave cylinder other than bleeding issues. After many hours trying to bleed the air out in an attempt to get a nice pedal feel, I eventually bought a 4’ length of clear plastic tubing that fits onto the bleed nipple and point the other end back into the master cyl reservoir, then pump the clutch pedal till no more air appears then close the bleed nipple. No need to bother her indoors to pump the pedal for you which leaves her more time to make coffee and scones.
Ian

[gjz30075]

Bleeding made easy.

[StressCraxx]

Hello James,

All the above is true, the stock slave works well, particularly if you keep the slave and the hydraulic line away from the exhaust header. Your Escort's RHD? Then Bob's your uncle.

Regards,
Dan

[prezoom]

It's all part of the old age, read stubborn, learning process. I didn't havre a remote pedal assembly, and I am not sure, even if I had one, I could relate the exact clutch release point. With the Zetec, the flywheel is approximately 1" closer to the rear of the block than the flywheel is on the twin cam. There is a difference also between the thickness of the clutch covers and the location of the fingers. I did some measurements with the engine on the stand and mounting the gear box to the engine, trying to look back up through the hole where the throw out arm exits the bell housing. I thought II had taken in all the variables when I made the new bearing retainer, but in the end, I came up about 3/16 " short. The engine/gear box was installed in the car and clutch would release, but that was with the pedal all the way to the floor, and the clutch was still dragging a bit. So everything had to come back out and a spacer was made to fit between the slave and the bearing retainer. An easier way to mount the slave, would be to make spacers sleeves that would fit between the original bearing retainer and a mounting plate for the slave. One reason I did not go this way, was I didn't want to have to possibly modify the original bearing retainer by shortening its sleeve.

The Contour/Mondaeo slave/release bearing is spring loaded to keep the bearing in constant contact/pressure against the release fingers. Not something I was familiar with, being old school. The slave has a sleeve that the bearing rides on, similar to the original bearing retainer. This spring puts the bearing at the extreme end of the sleeve, when unassembled. The sleeve has a raised section at the end to keep the bearing from being pushed off by the spring. So, when installed, the bearing is pushed back against the spring, compressing it, and the front end of the sleeve is exposed. The spring is fairly strong, and I mean strong enough to make pushing the bell housing onto the engine is a one man challenge. I soon figured out that rotating the engine on the stand so the flywheel was now horizontal, and using my cherry picker to lift the gear box so it was vertical, the weight of the gear box nicely compressed the spring and it would drop right on, smooth as silk. Actually it is now my preferred method of installing the gear box, spring or no spring. No more thrashing about trying to align the input shaft and getting the bell housing on the locating pins. With spring loaded releases bearing, it would be very difficult to try to fit the engine separated from the gear box.

During the conversion, I had the engine and gear box in and out more times than I can count. In the process, I converted the chassis to the Spyder style, with the rubber mounts installed on the chassis and new mounts constructed to go between the mounts and the engine. From the Mods section on installing a Zetec into a Plus2, I copied C42's method. This eliminated the "bell housing" lock situation. The chassis was reinforced in the vertical section to accommodate the rubber mounts. Bud English and I had many conversations about the conversion, and I learned a lot from him, as he was a few steps ahead of me in the conversion process.