i still cant drive this thing. we found a leaky master cylinder as the culprit of clutch disengagement. as it was old adn seeping. The flywheel is spaced back 1/8 of a inch due to the balancer plate for the 400. The only thing i changed was i put a 1/8 longer slave pushrod in place because i was thinkin pushrod length may have a problem with disengagement, but that wasnt the case.

I can install the new master, and it will depress just fine till i get some pressure in the master adn then i hear a pop noise and fluid comes out the top, it has happened twice now on NEW master cylinders.

could the longer pushrod be causing a pressure problem that the master cant handle, or am i missing something here

im gonna swap a auto in this winter, but i need to get it mobile for the time being.

any help?

 

anyone have a idea?

 

Think about what you've done:

If your slave rod is 1/8" long, then if the everything else in the system is unchanged from stock, the slave cyl is depressed 1/8" more than it should be.

If your flywheel is 1/8" back from the stock location and all else in the system is unchanged from stock, then the slave cyl is depressed an extra amount, equal to 1/8" times the leverage of the fork; somewhere around 2½ or 3 to 1, or around 3/8".

So in effect, the 2 changes you have made, have mis-located the slave cyl piston by around ½" to 5/8"; or, essentially, it's now offset by ITS ENTIRE DESIGN STROKE of .6".

I'd say it's now thoroughly messed up.

My recommendation would be, put the slave rod back like it belongs; and add about ¼" of spacer between the slave cyl mounting and the BH, to compensate for the flywheel being in the wrong place. That should put the slave cyl piston's stroke back into its correct operating range.

 

so could that be causing a pressure problem that the master cylinder cant handle? the slave hasnt popped, but the master has twice

 

I don't know, since I've never taken one apart and seen what's inside; but given that it's pretty easy to figure out how far off everything is from where it belongs with it like it is now, I'd sure make every effort to put the geometry back right, BEFORE destroying any more parts. Evidently just buying more MCs and sticking them on there isn't very fruitful.

 

i diddnt intend on repacling cyl aft cyl aft cyl. but i just had gotten a bad one and replaced it then i noticed there was a problem.

im gonna put the shorter rod back in, now, what can i use to space the master back into place? washers behind the bolts or would that cause a problem with the slave cyl?

 

I think washers would probably be fine. I suppose if you got a piece of some kind of material about ¼" thick and cut the right shape out of it, that would be ideal; but probably overkill. Mostly it just needs to be spaced back from the fork (toward the front of the car, in other words) in accordance with that end of the fork being moved that way by the entire clutch assembly being moved toward the rear of the car by the "pork chop" weight.

I've seen alot of people have trouble with those over the years, by the way, although I've also seen some that they worked fine. Usually auto cars are more likely to succeed than stick cars. This is why I typically recommend balancing the flywheel itself. About 8 or 10 ½" holes about 5/8" deep around the edge on one side, is all it usually takes... not too traumatic in the grand scheme of things. Most any balance shop can do it. But if it's done that way, everything stays all in the same place and fits right and doesn't cause problems.

 

i think im gonna put a few washers behind the slave cylinder and put the shorter pushrod back in, see what it does. hopefully a new master cylinder and this solves the problem.

it needs to move