Can't find the bleeding port?

[Clumber]

At 49 hours its time to change the hyd oil filter. Below are two instructions from my PT-425 manual which are not very useful. I cannot find the port needed to bleed any air that may get into the system when changing the filter. I also can't seem to find the Tow valve and related ports. Any help is appreciated. Photos of my engine compartment are attached.

 

[J_J]

If your PT is using the Sauer Danfoss Series 15 Hyd pump, here is the PDF on that pump . Pay attention to page 10 ,13, 23.

If you have another model pump. go to their web site and track it down.

http://www.sauer-danfoss.com/stellent/groups/publications/documents/product_literature/bln-9646.pdf

It says something about removing the plug from the charge pressure port, and I think you should have a fitting that screws in with a hose to bleed the air. Disable the engine, and only crank in short spurts for about 20 sec each.

 

[coolconnection]

Well I am just taking a guess here but on my PT-425 the port is on the other side of the tractor. (your picture doesn't show it) My port is on the drivers side further back and deeper in the engine. Those gold caps like in your 3rd picture are what you are looking for. Remove the cap and attach the hose. I don't know what you mean by tow valve but the hose is supposed to connect between ports so you can tow it. I bet your 3rd picture is one of the ports you need to connect to to tow it. Like I said look on the left side as you are sitting on the seat, further back and down low. I bet it is there covered in dirt like mine usually is. Let us know.

 

[J_J]

There is an air bleed and a tow valve, two different things.

I am thinking that the tow valve works a little differently, at least on mine it does. In one of the pictures in the PDF article, it shows a handle that when secured tight, the fluid flows normally from from input to output. With my tow selector bolt, if I turn it to tow mode, it opens two relief valves so fluid can move through the pump and circulate through the wheel motors, providing some fluid flow to the hyd motors. The relief orifices are small, so only a small of amount of fluid can flow. This process will generate a lot of heat, and therefore they only recommend to tow at a very slow speed. When towing, the hyd motors are acting as a pump. The hyd wheel motors with case drains, may run out of fluid since the fluid from the case drains go to the pump case and then to tank. If you run out of fluid, you might be sucking air.

 

[Clumber]

Well I am just taking a guess here but on my PT-425 the port is on the other side of the tractor. (your picture doesn't show it) My port is on the drivers side further back and deeper in the engine. Those gold caps like in your 3rd picture are what you are looking for. Remove the cap and attach the hose. I don't know what you mean by tow valve but the hose is supposed to connect between ports so you can tow it. I bet your 3rd picture is one of the ports you need to connect to to tow it. Like I said look on the left side as you are sitting on the seat, further back and down low. I bet it is there covered in dirt like mine usually is. Let us know.

Thanks for responding. Here are pics from the "drivers" side. Those caps appear to be Tube caps shown in the CAD drawings attached. Two of them connect to the Tram Manifolds shown on the tram circuit. Also see the tube cap on the T-adapter shown in the treadle circuit. It is on the drivers side above the cap for the tram manifold. Is this the bleeder port?

 

[woodlandfarms]

Uhmmm again, for 50 hours that is the cleanest tub I have ever seen.


AHHHHH Just as I hit send I see new pix, much more like a well loved machine

 

[Clumber]

There is an air bleed and a tow valve, two different things.

I am thinking that the tow valve works a little differently, at least on mine it does. In one of the pictures in the PDF article, it shows a handle that when secured tight, the fluid flows normally from from input to output. With my tow selector bolt, if I turn it to tow mode, it opens two relief valves so fluid can move through the pump and circulate through the wheel motors, providing some fluid flow to the hyd motors. The relief orifices are small, so only a small of amount of fluid can flow. This process will generate a lot of heat, and therefore they only recommend to tow at a very slow speed. When towing, the hyd motors are acting as a pump. The hyd wheel motors with case drains, may run out of fluid since the fluid from the case drains go to the pump case and then to tank. If you run out of fluid, you might be sucking air.

Thanks JJ, I am asking two separate (but related questions), where is the port that I connect the supplied air bleed hose. Since we are on the subject of the system pump, where is the Tow valve in case I have to tow the tractor.

I cannot tell what brand of system pump in on my PT425. The ones in the PDF look very different. I am hopping that one of the tube caps described in my previous post will be the bleed port... The tow valve remains elusive.

 

[J_J]

You need to find some numbers/letters on that pump, or have PT send you something that is comprehensive and detailed. Yep, I know, hold your breath.

 

[Clumber]

You need to find some numbers/letters on that pump, or have PT send you something that is comprehensive and detailed. Yep, I know, hold your breath.

I am going to clean the engine compartment today and look for numbers and labels. PT usually removes the labels though. I guess I will have to call them.

 

[coolconnection]

Well Clumber your first picture is of the engine oil drain cap. A long socket extension works good on that one. Now for the bleeder port. On your latest pics, the 4th picture is a good one. I have used both and they both work as bleeders (I know I made a mistake) but I am going with the top one as the direct bleeder. Now we don't have a tow haul valve that turns like the bigger units. We have the oil hose, yep that nice little hydraulic hose PT gave us with the tractor. You connect one end of the hose to that lower port in your 4th picture and connect the other end to the port in your 3rd picture (first set of pictures). Go slow and the oil just goes through the hose as you move the tractor. No easy free wheeling on these tractors. Hope this helps.