AW-4 Auto Transmission direction of fluid flow

[lawsoncl]

If you add a filter, make sure it has a pressure bypass.

[Saudade]

The numbers I posted earlier are the max pressures. In Reverse, parking brake on, wheels blocked, wide open throttle.

The numbers at idle are significantly lower.

(6) Shift transmission into D range and note line pressure with engine at curb idle speed. Pressure should be 53-to-61 psi (363-to-422 kPa).

(8) Shift transmission into Reverse and note line pressure with engine at curb idle speed. Pressure should be 73-to-87 psi (500-to-598 kPa).

However, also bear in mind these are at the test port, not the outlet. I could not find any mention of pressure testing at the outlet itself. The outlet itself only needs enough pressure to push the fluid through the cooling circuit.

[maxbraketorque]

Originally Posted by lawsoncl

Oil coolers should fill from the bottom, so they don't trap air. I doubt you'll see more than 50-psi on the coolers, since the discharge is straight into the pan.

Excellent point. In this regard, the only pressure will be due to the fluid viscosity relative to the passage dimensions.

[RCP Phx]

Originally Posted by lawsoncl

Oil coolers should fill from the bottom, so they don't trap air. I doubt you'll see more than 50-psi on the coolers, since the discharge is straight into the pan.

This I've been unable to confirm, maybe will try next time I have the pan off!!!

[mhead]

I agree, pressures are those expected at the pressure test port and not necessary the pressures in the cooling circuit.

The pressures mentioned can be seen in the operator's manual page 7,8 which gives the pressure measurement location as "test port". Link to manual is shown below.

"discharge straight into the pan" is an excellent clue. The interior of the transmission runs at atmospheric pressure due to the vent at transmission top. So the pan pressure is atmospheric and at least the pressure at the return point is known.

Unless someone has a more certain cooling circuit pressure, I'm going to keep to my transmission line hose and hose clamp rig.

Thanks for replies!

https://cdn.xjjeeps.com/pdf/en-us/aw...nformation.pdf

[mhead]

Here's another link to a cooling circuit pressure discussion... but no definitive answer.

https://www.naxja.org/forum/showthread.php?t=968375

[RCP Phx]

I decided to get a answer to this and my fuel pressure. I have a #6 test port coming tomorrow!

[maxbraketorque]

Originally Posted by RCP Phx

I decided to get a answer to this and my fuel pressure. I have a #6 test port coming tomorrow!

I guess you mean a -6 AN test port? Gonna put it at the trans outlet and inlet and/or cooler inlet and outlet?

[RCP Phx]

I will do everything at the trans because it's easier and I have a SAE quick-connect on the radiator. The gauge is electric so I will be able to read the pressures under all load conditions. Same is true for my fuel system but using the quick-connect .

[Saudade]

Very nice! Very clean!!

[techno1154]

Originally Posted by RCP Phx

I will do everything at the trans because it's easier and I have a SAE quick-connect on the radiator. The gauge is electric so I will be able to read the pressures under all load conditions. Same is true for my fuel system but using the quick-connect .

Looking good! Who built that radiator? Going the e-fan too... by the looks of the shroud.
My e-fans have done me well for the almost twenty years I have been using them (twin Derale with an advertised 4,000 CFM).

[RCP Phx]

Originally Posted by techno1154

Looking good! Who built that radiator? Going the e-fan too... by the looks of the shroud.
My e-fans have done me well for the almost twenty years I have been using them (twin Derale with an advertised 4,000 CFM).

It's a Griffin that came with the shroud but I use the factory design because of the mechanical AND electric fans.