QuestionQUESTION: I'm working on a 73 MG Midget that recently shattered the release bearing totally. Was able to remove the engine minus the trans and replaced the pressure plate, disc, bearing, and release lever insuring that the disc was in the right dirrection towards the engine. Engine runs great now however I now have no clutch operation. I replaced the master , slave, and slave hose but still cannot get the clutch to operate. Pressing on the pedal but see no movement on the slave unit. removed the slave unit from housing and can manually move lever by hand and seem to have good movement of bearing. We have made about 5 attempts at bleeding the clutch with no success. once slave unit is reinstalled there is no freeplay at slave unit, is this correct? Will again try to bleed brakes again today. If you have any suggestions let me know. many thanks Bob Sabin
ANSWER: Hi Bob,
I sent one responce but it may not have went out so here it is again,
I am concerned about your statment "there is no freeplay at the slave unit". If there is just no freeplay but the slave rod is not in a bind nor under load, it may be OK but if the slave rod has a lot of pressure on the clutch arm, then there is a problem that needs to be corrected before you go any further. The system can not operate that way. The possible causes are,
The slave cylinder piston is stuck.
The wrong release bearing was installed. (3 possibles)
The wrong pressure plate was installed. (several possibles)
The wrong transmission was in the car.
Someone lengthened the slave cylinder rod (a common practice)
Did you compare each new part with the old part? The three different release bearings that will fit are noted by the offset in the side pins. Your car should have almost no offset in the side pins meaning the pins are directly on the side of the bearing carrage the holds the carbon bearing.
To see if the piston is stuck take a pry bar and force the arm toward the slave cylinder. This forces the rod into the cylinder and pushes the piston into it's bore. If it is solid and no movement at all and the slave rod is under pressure then something is wrong inside. To test this, remove the two bolts holding the slave cylinder to the bell housing and then slide the slave cylinder by hand back into place and measure how far it is to be able to force the slave back to line up the bolt holes. If you can slide it into place by hand and start both bolts by hand then it is ok. If it is off too far to put the bolts in by hand let me know how far it is off.
Let me know, we will cover the bleeding after this is correct.
Howard
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QUESTION: thank you Howard for your responce. We ordered all our parts for this car from Moss motor parts and compared them with the old ones for a 1275 engine. I worked on it again today still to no avail. last nite we removed slave unit and inspected it. I pushed piston in and out to cup with no binds. left the piston to end of housing near bootand hanging down to fill unit with new fluid. today i remounted unit and manually pushed rod into housing as far as it would go the remounted slave cylinder back onto housing HOWEVER inorder to put pin in therod i had to manually force the arm back almost a half an inch more. ill run your checks again tomarrow. the biggest think i dont understand is that with all the new parts and bleeding the system if i put on the brake there is no movement at all of the arm or slave unit shaft. we did inspect the slave unit shaft and someone has welded on to it. Hope this will help you. Many thanks Bob Sabin
AnswerBob, if someone has been welding on the slave cylinder rod then you must find a new rod. You MUST not have to force the arm to get the clevis pin in. The rod was lengthened at one time as I told you people did to correct for worn out release bearings.
Forget the fluid until you get this corrected. Even if you had the system bled correctly the clutch will not work correctly as long as there is a load on the arm. With the arm under load if you had the system bled and depressed the clutch you probably would have destroyed the clutch disk, pressure plate and bearing in one step of the pedal.
Howard
