Was rebuilding my rear calipers on my 88 GT and discovered it had pistons with no vent holes on the outside. Anyone else have or seen these?

Every other 88 rear piston I've seen are vented with the rubber seal.

The previous owner mentioned to me that he had had the brake recall done at the dealership back in the early 90's but the brake recall was only up to 1986 models so I figured the dealer just changed his brake pads or something and sent him on his way.

Pictures: Standard rear piston on the left from a spare caliper had lying around. The sealed pistons on my 88 GT on the right.

Is normal for any w/ "Recall Kits." Recall covered Fiero and other Stick cars w/ same rear brake design.

For recall work, GM replace "Belly button" pistons w/ Black finish pistons w/ very small vent hole on the Side near the front of unit.
Hole hinds under the dust boot before "O-ring" sealing area to deal w/ brake fluid.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 05-11-2022).]

quote Originally posted by theogre: Is normal for any w/ "Recall Kits." Recall covered Fiero and other Stick cars w/ same rear brake design. For recall work, GM replace "Belly button" pistons w/ Black finish pistons w/ very small vent hole on the Side near the front of unit. Hole hinds under the dust boot before "O-ring" sealing area to deal w/ brake fluid.

For an 88?