Conflict in my brain.

J_J · May 25, 2007

NJBill said:
J
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 VIV part 1, and that goes to the tank, it appears to take the unwanted amount from the VIV 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 !!??

Thanks Bill,

Tram, might not be the best word to use , but one of the definitions is TO MOVE OR CONVEY. Now that is what the pump does, but we could use other words, like VD pump, variable displacement, but that wouldn't sound right. I guess the most correct word to use is, VSP, variable speed pump. It is a puzzle as to why they are only using the output from the joystick valve to go back to the cooler. That circuit is fed by a low volume pump and feeds the steering circuit/joystick valve. Is the line going back to the cooler the output of the joystick valve, or is this just a bleed off just to get some cooling for the whole machine. Otherwise, is hydraulic fluid flowing through this line when you have the engine running. What I am getting to, is that the steering and lift circuit is fed by a gear type pump, and the fluid has to be moving all the time, whether it is lifting a cylinder, or steering. The PTO fluid is also moving all the time, generating heat, and the PTO output goes back to tank.

Bill, you are only one of a few people that has traced out the lines, but does it make any sense to you. You would think that all fluid would go through a cooler before going back to tank, and that all fluid would be filtered at the source. Very poor design in my opinion for longevity.

NJBill · May 25, 2007

JJ
A lot of things on the PT's are not as they should be, but you have to admit they produce a working unit, for a minimum of cost.
Here is the steering schematic, the pump is fed fromthe bottomof the tank, right side. The PTO valve has also been utilized to accomodate the steering circuit, when required, the fluid is sent to the steeering valve, when not wanted it is allowed to return to the tank.
When the fluid goes to the steering pump, it can also flow to the lift/tilt as needed, when not needed it will return to the tank by way of the cooler. All the systems have some way of returning the fluid to the tank. Now, if you look at the tank on another thread, you will see all fluids return the bottom of the tank. You will also see that all fluids are withdrawn from the bottom of the tank, it's the coolest part, technically, it is also the dirtiest part!!??
Because of the location of the oil supply, I would have used a fully sealed lower baffle , allowing some fluid to move over it into the suction part,and put another drain plug onthe opposite side, that way the dirtiest fluid could be all removed at lesser cost, and the remaining cleaner fluid could be changed at less frequent intervals. Anyway I do not design for PT, after all it would mean drilling an extra hole and suppling another drain plug.

At an automotive school one time this type of subject was brought up and the instructor immediately went into the cost factor of X times a few cents.
To me that explained a reason for possible breakdowns when they could be avoided.

Here's the tank also