Hello,
I’ve been fighting a leak after installing a RMVB on my 1968 b-body 440. The history is no leaks with the auto valve body for the last four years. After installing the new valve body, there where no leaks when filling it at idle in park, neutral, or in gear. Fluid level was verified in neutral when warm. So I take it out for a ride and return to a trail of fluid up my driveway and 6-8” puddle dripping from the bell housing. I’ve verified it’s all coming from the bell housing and not the pan, dipstick tube, or gearshift seal.

I ended up pulling the trans and as expected the bell housing had a puddle inside below the pump. I’ve pressure tested the torque converter, inspected the bushing and front seal (plan to replace the seal anyway) and checked pump bolt torque with no issues found. On top of that, I find it hard to believe one of these things went bad right when I installed the new valve body.
Did I overfill it and it’s just puking out the vent?
Does the vent need to be moved to the rear with the new manual valve body?
I’m no trans expert, but could there be a pressure problem with the new valve body? I did check line pressure and it’s around 185 in neutral which seems ok.

Any help is appreciated before I reinstall the trans and have the same problem.

Thanks!
Jeff