no idle line pressure powerglide

[hemidakota]

I have a friend that has a powerglide in his altered. It has no line pressure in any gear or on brake at idle. At 2000 rpm it make 80 psi. This is at test port on servo cover. Cannot put gauge on rev. port in car I've been told. They have put 3 pumps and 3 valve body in with no change. The only thing that was changed orig. was all internals were swapped into an ati super case. The trans has been gone thru by 3 different builders and no problems found. I was wondering if the rear of the case where the governor cover is could be leaking causing this. I have not been over to check out, going tonight. Was just looking for a place to start. I have built a few powerglides and have never had any problems but by all means not a trans expert... Thanks

[bikeguy307]

I run a block off plate in all glides I build. So yes that is a place to start. It sounds like you are looking for a mis match with the new case.

[hemidakota]

I have the trans now. Have not tore it down yet. Did remove tail shaft and it does have a needle brg rear support that appears ok. I will get into it next week. One thing that struck me was the torque convertor was empty approx. 12 hours after running trans in vehicle. Not sure if that is anything but have never had empty convertor upon removal. I am sure there will be something wrong. Thing I don't understand is how it could be appart so many times by builders and no one found problem. I will give more info once torn down. Thanks...

[bikeguy307]

I would pull the pan along with the extention housing, install the converter, put the shifter in low and put air pressure to the port in the servo cover. This might expose the leak. Im guessing there is a bleed off of pressure somewhere seeing the different vb's and pump's that have been used.

[hemidakota]

Thanks Dan. I will check that first.

[hemidakota]

Pressure relief valve in valve body(hipster)was stuck wide open with some debris, cleaned the chunks out of it and no more massive leak. No other debris found so will see if it works. Thanks that air test pointed right at it. So maybe bull on the first story or I am missing something also.

[bikeguy307]

Awesome!! That sure would have caused the symptoms you described.

[hemidakota]

Works like a champ. 200psi now. Thanks Dan!

[bikeguy307]

Glad you got it!!