Hewland MK8/9 external slave rod question

[Garey Guzman]

I'm specifically working on a VFF and this is the first car I've had with the external slave with a rod that actuate the lever, which engages the TO bearing.
I've rebuilt the clutch master and external slave but can't seem to get enough movement to disengage the PP. Also new TO bearing and new bushing on the F3-style bobbin.
Per a friend, the rod can barely move up and down and rotates with my finger with no pressure applied. It makes sense that there is no pressure on the TO bearing when disengaged.

Any hints on getting clutch disengagement? It sure would make life easier on me!

[kea]

What size clutch master are you using ?

[Garey Guzman]

Clutch slave is .875
Clutch master is 3/4

These were on the car when I got, presumed to be on the car when last restored in 2004.

[Charles Warner]

Clutch slave is .875
Clutch master is 3/4

These were on the car when I got, presumed to be on the car when last restored in 2004.

Is the rod adjustable? Commonly there is a rounded end that threads onto the rod with a stop nut whereby you can adjust the length of the rod. You also have to be sure the bobbin is the proper one for the car.




BTW, package on the way Friday.

[Garey Guzman]

Is the rod adjustable? Commonly there is a rounded end that threads onto the rod with a stop nut whereby you can adjust the length of the rod. You also have to be sure the bobbin is the proper one for the car.

The rod is adjustable and I think it has proper slack (just about nothing into the slave cylinder but twists with my fingers), unless it should have some preload. But that doesn't make sense because I don't think pressure on the PP would be what you want when fully releasing the clutch.

Basically, I'm trying to see if I'm missing something obvious that people with this system have seen. (BTW, clutch m/c is same size as my DB6).

[Charles Warner]

The rod is adjustable and I think it has proper slack (just about nothing into the slave cylinder but twists with my fingers), unless it should have some preload. But that doesn't make sense because I don't think pressure on the PP would be what you want when fully releasing the clutch.

Basically, I'm trying to see if I'm missing something obvious that people with this system have seen. (BTW, clutch m/c is same size as my DB6).

Your comment of "just about nothing into the slave cylinder" is queer. Silly question, I know, but have you made sure the slave cylinder piston is fully retracted? The adjustment should be made with the slave piston fully retracted and the cup of the fork being held in place with the spring tension from inside the bellhousing through the bobbin.

[Angus]

On the slave cylinder on my car it is possible to trap air above the bleed screw port. I have to remove the cylinder and rotate it to get the bleed port at the high point to get the last 1/8-1/4" of air out of it. Hope this helps.

[Garey Guzman]

On the slave cylinder on my car it is possible to trap air above the bleed screw port. I have to remove the cylinder and rotate it to get the bleed port at the high point to get the last 1/8-1/4" of air out of it. Hope this helps.

Great suggestion! Since i got it to engage once with the engine running, although a bit roughly, this is a possibility. I'm also going to re-check the master cylinder attachements to see if I might have adjusted something inadvertantly during the refurbishment of everything.

[Charlie Schmidt]

On the slave cylinder on my car it is possible to trap air above the bleed screw port. I have to remove the cylinder and rotate it to get the bleed port at the high point to get the last 1/8-1/4" of air out of it. Hope this helps.

I tapped one of those universal 1/8 NPT bleeder screws into the top of the slave

[Roland V. Johnson]

Are you hitting a clutch pedal stop? Is the master cyl sticking in the bore and not returning? (is there a lot of clutch pedal free play) do you have aeroquip lines the length of the car?

[Bob Clark]

Make sure the posts on the cross shaft that hold the TO bearing are not bent or the welds broken. Pretty common.