JohnD

I rebuilt the calipers on the Z yesterday and put in new pads. I've done a few disk calipers, mostly Ford, but I never saw anything as hard to get in as the pistons on these. I finally pushed the pistons in past the new square O ring with a c-clamp. They seem to work ok so I guess everything seated alright. Anybody else had this experience? I was wondering if the tolerances could have been off on the O ring? Even without an O ring, the fit was pretty tight between the piston and the cylinder.

Z28LT1_Just_Nasty

How were the cylinder wall surfaces? Did you hone the cylinder? Did you use a brand new piston?

Another possibility could be that when you where pushing the piston into the bore, it was not absolutely square. It would be very difficult to push the piston in at a very slight angle.

JohnD

I pretty much looked into everything you mention. I tried the piston fit in the bore before I put in the "O" ring and it was ok. I didn't think it needed honing, that is more for wheel cylinders where the puck has to seat in the cylinder anyway. In any case, everything turned out alright and seems to be working well. I talked to a friend over the weekend and he said that a brake part lubricant product made by Permatex, which he referred to as "green slime" would have facilitated the process. When I do the back ones later, I'll give it a try.