So, rebuilt a B7XA on a 98 Accord V6...... and it worked beautifully the first time I put it in gear...but after the first time it shifted out of first gear it never went back into it. I did a complete rebuild on it. It has plenty of fluid. If I start in 2 and shift up into D3/D4 it shifts smooth, is strong and powerful......but it has no first gear at all. I’ve read the Helms manual on it and it gives me 3 options.....a defective accumulator, bad clutches, or bad gears. All the gears are perfect, the clutches in tolerance and new..... but how is an accumulator defective? My only guess is the O-ring for it is leaking even though I replaced it?? All of the solenoids were tested electrically and worked. I’m going to test the pressures tomorrow, but I need to take it out and fix it tomorrow and do NOT want to keep repeating this process. There are no Codes either.......any help would be greatly appreciated because changing the O-ring is the only answer I’ve come up with so far.

 

If the O ring had a tiny tear or the bore was not clean/properly greased or out of round the accumulator may not work.
Can't recall if the B7XA uses a spring or circlip to position the valve. If the seal rolled it would also lose pressure. Did you install the seal lubed or dry?
If you put it in 1 and hold the engine at a higher than idle rpm does it ever engage? You will want to have your other foot firmly on the brake pedal when doing this.

 

Is it possible the linkage is not quite right? Just adding another idea.

 

Figured out the answer..... it was an O-ring. 800 pieces and 1 O-ring Lol. Luckily it was on the end cap. There is a tube that transfers the pressure from the valve body to the “top” of the transmission and down into the secondary shaft that holds the first/second gear pack so it wasn’t allowing first gear to build any pressure at all.

The rebuild kit for those covers 4-5 different variations of that transmission so each “bag of O-rings” has 4-5 possibilities and apparently I used the wrong one and it blew out the O-ring when it tried to build up pressure. Luckily it was on the end cap and I didn’t have to break the whole thing down again.

Thanks for the responses and help!