Unknown B2 piston question

[C Sean Watts]

I was unable to find an answer about modes of B2 failure...

Is it possible that a B2 can 'wear out' ( spring, seals, etc.) fail or otherwise malfunction WITHOUT cracking and still look OK?


Possible related trans malfunction is -
Trans needs time to 'warm up' before engaging in forward gears, after that, functions as normal. Other aspects are normal and I do understand "something is sticking somewhere" is also a possibility.

It's out of the car and I'm trying to decide on keeping it as a potential spare to use later.

[C Sean Watts]

Anyone got any ideas?

[loepke72]

I know this isn't really specific to your transmission, but yes, a servo piston seal can go bad while the piston itself is still good. Sometimes the seal is replaceable, sometimes the seal is bonded to the piston. Not sure which type the B2 piston is, however. A common failure on older cars is for the seal to harden, then it will exhibit poor operation when cold, and may improve with temperature, like you describe. But a cracked component can do the same thing as the crack closes with increased temperature. Best thing to do is remove the part in question and inspect. If it's a bad seal, then a transmission overhaul is the best thing to do as the rest of the seals are thrown into question.

[C Sean Watts]

Originally Posted by loepke72

I know this isn't really specific to your transmission, but yes, a servo piston seal can go bad while the piston itself is still good. Sometimes the seal is replaceable, sometimes the seal is bonded to the piston. Not sure which type the B2 piston is, however. A common failure on older cars is for the seal to harden, then it will exhibit poor operation when cold, and may improve with temperature, like you describe. But a cracked component can do the same thing as the crack closes with increased temperature. Best thing to do is remove the part in question and inspect. If it's a bad seal, then a transmission overhaul is the best thing to do as the rest of the seals are thrown into question.

I think sometimes we tend to forget these cars are getting up in years and all seals will go bad no matter how good they were from the factory.