I have the dreaded rear brake caliper leakage on my 88 GT. I'm rebuilding
the caliper and piston. My question is there is a clear plastic washer in the
rebuild kit and I didn't note where it went when I disassembled the caliper.
My shop manual does not show where it goes. Can someone tell me where it
is supposed to go? I can guess where it goes, but I wanted to make sure I'm
right. A diagram would do wonders. THX in advance.

I'm also doing the piston rebuild per Silicoan86's post about getting the
seal from the Pontiac 6000 rebuild kit.

The plastic washer goes between the caliper and the rubber seal under the lever on the e brake shaft. The inner piston seal from the 87 Fiero rear caliper rebuild kit is the one you need for the 88 inner piston seal.

[This message has been edited by seajai (edited 08-22-2017).]

OK, So you are saying on the outside of the caliper, under the lever seal, under
the emergency brake lever. It's difficult to understand without the exploded
diagram of the caliper. I cannot scan the diagram as my printer is dead.

I believe either the 87 or Pontiac 6000 kit will do for the piston seal. I
already have the 6000 kit.

The kit is the same for both the pre-88 Fiero and the 6000. It cross references to a few cars of that era.