Sunday 9 August 2015

Clutch conversion part 1

I did some work on converting the clutch to include an air servo.

The original clutch mechanism was simply a bar joining the pedal to the release lever and was fiendishly heavy: you had to brace yourself against the seatback to move it. I picked up a new air servo on ebay some time ago; I think it's a Man Diesel part


This servo is operated by hydraulics so the pedal needs to activate a master cylinder instead of the old push rod.

I picked up a master cylinder and clevis from these people carbuildersolutions.com


This has (I think) a bore and stroke that will match the servo.

The original clutch pedal needed bending slightly in the vise and thinning down to accept the clevis. I reamed the hole out to 7/16"


and made a brass bushing for the clevis pin


Quite a milestone actually because it is just about the first successful thing I have made on my lathe!

The spring loaded 'captive' pin for the clevis is a really neat idea: mush easier than messing about with split pins.


So flushed with success I made a steel pushrod complete with 5/16" UNF thread cut on the lathe (woohoo!)


The whole thing sits on the truck like this



I'm not sure that I have the pedal stroke correct but it will be good enough to get started. It's difficult to tell without the cab on and the other pedal fitted and so on.