Conflict in my brain.

[Rivco]

Bob,
As I suggested to Kent in the " Bleeding the closed loop system". Not to worry about his schematic being in Tennessee, it could be all wrong anyway.

I also have a 422 Bob, with the same schematic in the "Manual" as you are showing, there were many things had me puzzled with all of the schematics.
I gave one to JJ like the one you printed, I have apologized to him since then and all being well I will send you the schematic which is correct for my 422.
It's a tough job for a sr. sr. on his own but it was well worth the trouble.
As you will see there is no cooler shown, it is not connected into this circuit, also you will notice there is the addition of the treadle valve.
The Variable Volume Pump Part 2 is responsible for the operation of the wheel circuit, any excess oil is directed back into V V part one from where it is sent to a return port on the tank. Any excess in the circuit per se is exited to another return port on the tank from the treadle valve.
In a way it changes the whole perspective of what happens when. Very simple really we are using oil at our choice of pressure and letting any excess return to the tank.
Anyway so that you can all chew the fat some more, here is my wheel circuit on my 422 checked very carefully hose by hose. Have Fun.

Mr. Bill, Your wheel motor flow schematic for the 422 looks very close to the layout for my johnny home owner 180. ( the 180 has no oil cooler) so I am a little confused with your diagram showing the flow route on your wheel motors. . How is your cooler plumbed in??? What's it hooked up to???> Your diagram is not showing the oil cooler.

 

[NJBill]

Hi Bob,
I bought my unit Mar 2004, The schematic was drawn Aug '98 and was revised May 2000.

As you can see I do have a treadle, I can only guess when they ran out of hydrovac parts, is when the treadle cxame into being.

The cooler line (1/4 inch) comes from the lower left port of the Sauer Danfuss valve, and leaves the cooler into the No 2 port on the tank.

We each have a PT, Now we have to wonder how many actual models are there ????

 

[KentT]

Hi Bob,

The cooler line (1/4 inch) comes from the lower left port of the Sauer Danfuss valve, and leaves the cooler into the No 2 port on the tank.

We each have a PT, Now we have to wonder how many actual models are there ????

What Sauer Danfass valve? The valves that control lift, curl and the Aux PTO?

My PT-425 (delivered in December 2000) sounds like Bob's PT-422...

 

[J_J]

I thought this article would be of interest to anybody that has a hydraulic system.

Hydraulic Fluid Viscosity

 

[KentT]

I thought this article would be of interest to anybody that has a hydraulic system.

Hydraulic Fluid Viscosity

JJ, you might have just found the "final answer"...

To quote that article:

Automatic transmission fluid, multi-grade engine oil and anti-wear, high VI (AWH) hydraulic fluid are commonly used in hydraulic systems that experience a wide operating temperature range. These fluids have a higher Viscosity Index (VI) than AW hydraulic fluids due to the addition of VI improvers. The higher the VI a fluid has, the smaller the variation in viscosity as temperature changes.

 

[NJBill]

I only have a rough drawing so far of the lift-tilt-aux pto valve circuit.
Kent
That's the Sauer-Danfass Valve
Rivco
You don't see the cooler in the wheel scematic, because on my PT it isn't.

For those of you who don't mind looking carefully at schematics, as I mentioned earlier the cooler line comes from the lift-tilt-aux pto valve bank, and from the cooler goes to No 2 return port of the tank.

Remember this is my PT, I'm positive there are many more variations of the hose layouts, even on the same designated models, mine is a PT 422.

Bill

 

[NJBill]

Forgive me for taking up your valuable time.
I've made a few changes on my lift tilt drawing, and a couple of photos to supplement my description of where does the cooler line come from.
Bill

The white tape in each photo is the cooler line leaving the Sauer Danfass, then sneaking into the tunnel to find it's way back to the engine cover.
Bill

 

[J_J]

Forgive me for taking up your valuable time.
I've made a few changes on my lift tilt drawing, and a couple of photos to supplement my description of where does the cooler line come from.
Bill

The white tape in each photo is the cooler line leaving the Suer Dana's, then sneaking into the tunnel to find it's way back to the engine cover.
Bill

Bill,

You are not taking up my valuable time, I am retired, and loving it. By all means continue to provide data on what ever machine that you have. We appreciate your efforts.

Your schematic of the joystick valve, shows a line running back to the oil cooler. Is there any other line that connects to this line and back to the cooler. One question is, is this the only line going back to the cooler. Next question, is there a line running from the tram pump back to the cooler? For instance, on my 1445, I have a coupling block on the right rear, that several lines connect. I believe Thai they are the case drains, and the output of the charge pump/tram pump. from this block, a line runs to the cooler

Does everyone know that you can bypass the temp switch that controls the fan. By doing this you get a jump start on the cooling , Just a SPST switch on the dash that you can toggle on whenever. You can then leave it in the auto mode, of manual mode. Some of the temp controls don't come on until around 150 degrees.

 

[J_J]

This hydrostatic pump depicted below is similar to the one that I have in my 1445, but the charge pump is built in. I have a pump on the back , but it is the PTO pump. In the description they mention case drain, so therefore I am thinking that the charge pump overflow goes into the case drain and out to the cooling circuit. I am trying to get the guys at Eaton/Cessna to explain the pumps operation.

Surplus Center Item Detail

 

[NJBill]

JJ
I knew you would enjoy this situation. All my schematics show each hose on the PT, where they begin and end, so to answer your question that 1/4 inch hose takes care of all the cooling.
By the way one of the first changes I made on mine was to bypass the Temp switch at the cooler.
Heres a real handy man picture for you to enjoy, I've tried to show every port on each section, and what they do. As you can see there is only one port on what I call the VV part 1, and that goes to the tank, it appears to take the unwanted amount from the VV part 2 which is the wheel drive section.
The word tram is confusing me the only tram I know is like the one in the picture which I used to ride as a kid !!!
Bill

ps I'm also retired !!??