Wednesday, March 11, 2009

M.C.A. '09 continued



  upon closer inspection of my MC yesterday i noticed a small flaw in the rear piston which controls the rear brake circuit: its spring seat doesnt grip the tail of the piston like its supposed to, so that could cause the valving to not work properly. so maybe that had something to do with it, maybe not. also, a member of the 411/412 forum suggested polishing the brass shim "flap valve" and its mating surface on the piston with 2000 grit, so i'll try that too. 



  i also removed the reservoir and hoses to clean it. there was some black goo in the bottom around the fluid outlets and the old blue hoses have always leaked a little bit. i plugged the inlet hoses with a pencil like i usually do for fuel hoses, but the DOT3 dissolved them like acid, and now theyre stuck. i was going to replace them anyway, i guess...



  the holes in the body that the hoses pass through had been suffering with oozing brake fluid since i bought the car. luckily the paint damage wasnt too bad. note the third hole for the hose that feeds the clutch master, already punched open even though the wagon was never fitted with the 4-speed from the factory...


  below are the pistons, front is at the bottom, rear at the top. the front piston's spring is fastened to it with a small screw through the cap at the end, but the rear piston's spring doesnt have this part and instead relies on the stamped metal seat's friction fit to hold it all in place. i dont really see how this could have much of an affect since its all held together with pressure from the springs once assembled in the cylinder, but every detail counts, i guess. its this spring that controls the operation of the valving in the piston along with the brass flap valve and seal. 


  once my rebuild kit gets here i get to figure out a way to remove & replace the forward seals of each piston, the ones captured in deep grooves, without destroying them.

the tracking # shows delivery tomorrow...