Spewing foaming PS fluid update

[Fred Werring]

Few months back I wrote about the PS fluid foaming up and spewing out the cap on a 5000 with the old style separate reservoir.
Was using UTF as the fluid like I do on the rest of my Fords. Changed the filter, didn't help.
It was sucking air from somewhere, never did find out where.
But flushed the system out, and used type F transmission fluid instead.
Still sucking air (I watched with the lid off the reservoir), but the Type F doesn't foam like the UTF does.
So no more spewing. And if it's leaking out, I haven't seen it in the fluid level.
So it may not be fixed, but it's functional.

 

[Cutlass327]

Only place a pump system can suck air is upstream of the pump - the reservoir, or it could be the pump cavitating.

If it was downstream of the pump, you'd see the leak, as that part is pressurized.

Has all air been bled from the system? Maybe rig a hand vacuum pump to the reservoir top, put 10-20 inHG on the reservoir to remove the air in the pump and system.

 

[Sean in PA]

Depending on the type of fluid, a clogged filter can cause foaming without any leaks in the system.

 

[Fred Werring]

Depending on the type of fluid, a clogged filter can cause foaming without any leaks in the system.

I replaced the filter

 

[Fred Werring]

Only place a pump system can suck air is upstream of the pump - the reservoir, or it could be the pump cavitating.

If it was downstream of the pump, you'd see the leak, as that part is pressurized.

Has all air been bled from the system? Maybe rig a hand vacuum pump to the reservoir top, put 10-20 inHG on the reservoir to remove the air in the pump and system.

My understanding is air can get sucked in around the pump shaft seal.
And there is the possibility of a pinhole in a return line, causing a venturi effect, drawing in air.

But with the change to type F atf, it's not spewing out the top anymore. So it's functional, the need to really dig into it has gone away.

 

[a49deere]

I just got done rebuilding the PS pump on my 3910, I also used UTF. While I was working on tractor, I turned steering wheel to get tire out of my way. Fluid shot out all over the place!! Ugg!! After rebuilding pump, filling and driving while turning sharp left and right, I also had foam. After refilling pump several times, foam is gone. It did take a bit to get all the air out of system even after all the left and right turns.