Saywhut

I recently purchased a "corvette servo " kit for my 88 700R4, it came with a .500 boost valve & sleeve, and new accumulator pistons.

The trans has been rebuilt with the B&M (I know) full Transkit, with the valve body at the "street" level.

I've installed the servo, which gave me a quicker shift, which is good.
I'm not clear what the boost valve & accumulator pistons will do:

I know the boost valve will raise the line pressure, will this make it shift harder, or earlier, or what?

Will the accumulator pistons make it shift earlier, (at a lower rpm), or harder, or both?

Can I change the boost valve without removing the valve body if I decide not to use the accumulator pistons?

BTW, Thanks to you & Probuilt, & all others that take the time to help us novices, I've got a lot from just reading the posts here!

Pro Built Automatics

The new .500 main boost valve installs in the front pump and does not require the removal of the valve body. The new accumulator pistons, 4th accumulator installs up into the case behind the valve body plate, the 2nd accumulator pison installs into the 3-bolt aluminum cover next to the valve body. The purpose of the new accumulators is to prevent cross leaks and give better control (slightly firmer) of the 2nd & 4th gear shifts. DO NOT BLOCK the 2nd gear accumulator, use a late 1991 & up accumulator spring here.
Hope This Helps!!!

transfixleo

I can't add much to what Pro Built said. The pistons wear out in the center and cause an internal leak that can lead to the band burning. The boost valve will not affect minimum pressure but will greatly increase boosted pressures depending on what you had in it to begin with. I would install the case accum, spring first, then piston. Take out the hollow blocks on the accum pistons from the B&M kit.

Saywhut

Thanks guys!