Mainline pressure problems AGAIN!

[Morkai]

Well, I just checked my pressures, and wasn't happy. What could be doing this, I had decent pressures after it was built a few thousand miles ago.


P/N - 60(min tv) 180-200(max tv)
R - 95(min) ~130(max)
OD/D - 60(min) ~130(max)
1/2 - 120-130(min) no change(max)

So I popped the PTS PR kit with the larger rev. boost valve:

P - 125(min tv) ~190(max tv)
N - 180(min) 180(max)
R - 130(min) 135(max)
OD/D - ~130(min) no change(max)
2 - 130(min) no change
1 - 120(min) no change

 

[LV GN]

maybe the inner valve is in backwards?

 

[Morkai]

You mean the rev boost valve? I don't think so, but who knows..

 

[Morkai]

I don't understand why I only have decent max psi in P and N, I am almost certain I had over 200psi in low 1 & 2 after it was built.

Is it possible this isn't a pump issue?

 

[LV GN]

Originally posted by Morkai
I don't understand why I only have decent max psi in P and N, I am almost certain I had over 200psi in low 1 & 2 after it was built.

Is it possible this isn't a pump issue?

not if it was ok before you change the set-up. you have something wrong in the line up of the valves.

 

[Nordbert]

PR Valve lineup

Your pressures do seem low, like no boost. Check out this pic. :
http://www.camarobay.com/images/Transgo/pumpvalve2.JPG
Do you have second gear starts with that much min. TV?

 

[Morkai]

LV GN:
Do any of those #'s look 'ok' to you? That's why I changed them. It was ok back after I built the thing a while back....now it's not

I built it then cause the first pump done something simular, I'm guessing I never took pressure readings from it after the build. Only when it started slipping.

Nordbert:
That is exactly how I possitioned them...
Well, I only got the .400 rev boost in tonight, so not yet. I did have one time in the past with that PR setup in it...


I'm just trying to figure out if my pump is failing or I'm loosing pressure somewhere else.

 

[Morkai]

Update:

Well, I just noticed something interesting. When I started it up cold, and dropped it into Rev, pressure shot up to 200-210, and the same with 1&2, but seemed to drop as I accelerated, then when it got warm it stayed down in the 120-130 range all together.

This sounds like I have a pressure leak somewhere when I'm in gear...any ideas what circuit it could be in?

 

[77 cruiser]

Does RPM seem to make any diff.?

Jim

 

[Morkai]

When? When it was cold it pressure would drop with rpm, once it's hot in gear it has little effect, might go up 10psi.

 

[Morkai]

This is all too familiar...

Looking back, this sounds almost exactly like what happened the last time. Have a look..

http://www.turbobuick.com/forums/showthread.php?s=&threadid=109017

I also looked back and found the pressure readings from when the tranny was freash this time around:

(min tv, max tv) rpm-idle(~800-900)
P 65 225
R 100 245
N 65 230
4 65 200
3 65 220
2 195 195
1 195 195

 

[Otto J]

Not to sound stupid, BUt is there a filter in the trans?
I did that one time before

 

[Morkai]

Filter

Yes, a 700r4 filter with an art carr pan and double seals.

 

[Morkai]

I have pressure!

I think I might've solved the pressure problems. I swapped my pump out for one out of an old art carr I have sitting around and it looks pretty good so far.

It's a nonlockup, so I had to swap converters too, also I noticed the artcarr pump has a rev boost valve with the O-rings on the outside, I wonder if that would've helped mine.

I haven't had time to take some proper pressure readings, but they look much better, and I was able to pull about 250 psi in low by giving it some throttle.

Clutches still slip at WOT, but they're probably toasted. Anything below that feels better.