I need help figuring this PSI issue.

[DorianL]

I just rebuilt my 200-4R. I have a complete PTS pressure regulator system and a PTS deep pan.

At 1000 rpm Park:

No TV: 100 PSI
Full TV: 260 PSI with a +/- 10 PSI shake on the needle.

The pressure comes up nicely and fast as I pull the TV cable but as the needle climbs the shaking increases.

It shakes the most when I pull hard on the TV cable.

Now here's the thing: if I raise the RPM to 2 - 3 - 5 - 5000 rpm, at full TV the pressure drops! And stays stable at 160 PSI. Less shaking at high rpm.

At 800 rpm the needle climbs above 260 PSI.

First I thought it was the oil level. I added a couple of quarts... no difference.

Then I thought it might be that the PTS oil pickup was sucking air. I visually checked the pickup assembly for holes but did not see any. Then I replaced two new seals... no difference.

What would it be? A hole in the pickup maybe? But the pressure reads stable at 150 on throttle.

The remaining options: something in the VB or the pump.

The trans shifts fairly ok when driving. But the pressure never goes over 160 since there is always some throttle.

I'd rather check the VB first before I pull the trans to get to the pump. But where should I look?

Can the pump be rulled out? Or can it be it becomes inefficient at high rpm? Could it be the pressure regulator? I had the pump rerbuilt (in Belgium) last year.

D

 

[DorianL]

Other notes:


My pressures at 1000 rpm at no TV and full TV are

P - 105 - 250
R - 180 - 210
N - 105 - 245
D - 107 - 210
3 - 105 - 210
2 - 210 - 205
1 - 195 - 195

But driving, mypressure drops to 160

 

[77 cruiser]

My thoughts are pump slide spring. Do you know what they did to the pump?

 

[chris718]

looking at the readings it is quite obvious that you have no reverse boost or manual lo boost pressure.very likely the signal oil pipe or rev int boost valve is installed upside down or sticking.

 

[DorianL]

Well, the signal pipe is well fastened.

I rermoved from the pump (in the car) the entire reverse boost, TV boost and spring/pressure regulator assembly.

They were in the right order. The reverse boost might have been sticking.

In anycase, I put it backk together... the problem is still there.

Anything I can check kin the VB before I drop the trans again and simply replace the entire pump?

I might try putting in a stock pickk up in there too. Maybe there is a crack in the PTS pickup tube? But then I presume it should not read a so stable 160 PSI at throttle.

D

 

[DorianL]

Any other takesrs?

Rather take the VB off that drop the trrans again....

D

 

[mikestertwo]

As Chris said, are you sure the lo/reverse boost valve isn't upside down? Another possibility is a broken vane ring in the pump. I can't think of anything in the valve body that would give you the pressure fluctuations. I think your going to have to pull the pump out and take a look.

 

[DorianL]

I was afraid you'd say that.

I don't know what they did to the pump... this is Belgium. You'd hope they do it right... HOPE! Only 5% of the cars here are automatics.

The long, thin part of the reverse boost valve hangs down in its bushing, correct? It hangs out about what, 1/4 inch or more?

There is a whirring sound at full TV, by the way.

D

 

[mikestertwo]

Sounds like you have the boost valve in correctly. Pull the pump.

 

[DorianL]

< sigh >

I wish I had a garage... cold out here...

 

[mikestertwo]

Not too warm here either 16*F

 

[DorianL]

90 minutes to drop the trans just by night fall.

I dropped the pan and loosened the bolt holding the oil pick up. Then I shook around the pickup... it was quite wobbly! Hmmmm

Could well be that my problem was there. Oil seal might not have been in deep enough.

Hmmm, I guess I disassemble the pump...

Not sure that pickup issue explains the problem I have been having.

D

 

[mikestertwo]

The seal looks like it is sitting in the normal place.

 

[DorianL]

Hmmm, nothing I can see that is unusual.

I took it all the way down... looks fine to me. Vanes and everything.

I pulled out all the valves. The TV boost valve might have been slightly sticking. The reverse boost looked just fine.

Beginning to think it was the pick up after all.

Grmbl...

Are we sure nothing in the VB could affect this? Maybe the pump gasket?

 

[77 cruiser]

Dorian I had a similar problem a few years ago, high RPM press. loss. Installed TransGo pump rings & the pump slide spring they supplied & I now have stable press. @ any rpm. I still suggest pulling the pump apart.

 

[Lee Thompson]

scarf cut sealing ring

Check the ones on the input shaft --make sure one isn't cut.

 

[S10xGN]

Is it me, or does it look like 2 seals in there? Two seals can cause air to be sucked instead of fluid...

 

[DorianL]

According to PTS, their oil pick up needs two seals.

Hm, I like the idea of the rings + slide spring. That might explain the whirring sound.

the seals on the inputshaft look fine; I just replaced them.

D

 

[77 cruiser]

Like this.

Product Information

 

[DorianL]

I think I need a new pump.

I replaced the pickup oil seals and things improved slightly.

I read at idle no TV I get 100 PSI and 280 at full TV. Blipping the throttle makes the needle dip to 220 - not as bad as before. So there maybe a slight problem sealing there still.

BUT when I take the car out for a spin, the needle drops closer to 150. I am presuming that this may be related to heat. The pump expands and the seals fail more. There may be some internal issues to the pump too. Maybe there is a nick in the pump/pick up bore? Thought I could feel a small nick there.

I think I will order a bowtieoverdrive pump 13-vane (over my 7) and swap over my PTS pressure regulator kit into it.

D