New Member, New Owner of a 425

[MossRoad]

For clarification, the older PT400 series used a cable that ran from the treadle pedals back to the tram pump that operated an arm on the tram pump to control direction and speed. That cable is called the hydroback cable.

Newer models ( I don't know what year they changed ) switched to a hydraulic valve operated by the treadle pedals. Hoses from that treadle valve run back to fittings on the tram pump. Fluid movement in the treadle circuit controls direction and speed in those later models.

 

[JGZahn]

Toy,
The pump was already disconnected when I got the tractor. Several of the wheel motors had the hoses off as well. The shop had disassembled the unit and there is damage internally. I haven't pulled the motors off yet.
JZ

 

[J_J]

If there was a pump failure or wheel motor failure, you will need to inspect and flush the total hyd system.

Like someone said, the only filtering is in the suction side of the tram pump. The charge pump is pumping about 10% of the VSP/tram pump flow.

If you can't rebuild or find the same pump, you will have to search for and find a pump that will pump about the same flow and pressure to match the engine HP.

It will have to fit in the same space and you may have to change how the pumps flow rate is operated, otherwise tram speed.

 

[ponytug]

In researching pumps, there is the added complication that for PTs, we need a main drive pump that has a pass through drive shaft to drive the auxiliary and PTO pumps. This limits the choices somewhat.

If you decide to replace both the pump and the motors, you have more flexibility about flow/rpm tradeoffs.

All the best,

Peter

 

[MossRoad]

In researching pumps, there is the added complication that for PTs, we need a main drive pump that has a pass through drive shaft to drive the auxiliary and PTO pumps. This limits the choices somewhat.

If you decide to replace both the pump and the motors, you have more flexibility about flow/rpm tradeoffs.

All the best,

Peter

That also depends on the model year. My 2001 PT425 has the tram pump in front of the engine and the two section main PTO/steering-lift-aux pto pump behind the engine.

 

[ponytug]

Right, MR, thanks for the reminder. My apologies.

All the best,

Peter

 

[MossRoad]

No apologies needed. I don't know what model year that change took effect.

 

[JGZahn]

From what I can tell, I have the hydro controlled pump (not cable). All the pumps are in-line with none mounted seperately. I have the V-twin Robin/Subaru engine and a plastic fuel tank. The model/serial number is 18024, I have no idea what year it was made as yet.

 

[JGZahn]

Toy,
No prob, the unit was well used when I got it. A friend of mine did landscaping and snow removal with it for years before the the pump failed and he bought a new one. To bring everyone up to speed, still no progress by the shop that has the pump. There is another larger local shop that I'll call to see if they can do anything with it, worst case I ship it to Power Trac and have it rebuilt. I was hoping to avoid the shipping cost and have it done locally, so we'll see...
JZ

 

[toy]

jgzahn when I read where the pump and wheel motors was unhooked it gave me the thought that when the machine went down may have just started taking things apart without really knowing what was going on. I don't know how long of a trip it would be for you to drive to Tazewell but if that was a possibility for you it might be worth while to call pt and see if they could test your parts and see which ones they could rebuild for you or even if they were bad to start with. I believe they have away of testing the parts [wheel motors and pumps]to see their condition. The pt place used to offer a parts swap program where you could buy a rebuilt part and give yours as a core. I looked on their web site but couldn't find it but they still might offer it. When I heard of the rebuild option it was for cylinders and I don't know what else. I took a wheel motor to them and they rebuilt it for me, it didn't take them but just a few minutes to rebuild it and the price was real reasonable. Considering their knowledge of the machine, having a warehouse of parts and the right tools to test and repair equipment to do the job, it might be worth the time to take the trip to get it done yourself. The shipping costs would save you a lot to go on the trip there and you would get to see the new machines and attachments first hand who knows you might even come home with a new one. They will do demos of their equipment if you wanted to demo them, and it might be an enjoyable trip for you and the misses to make the trip. I hope you can get it running without a lot of cost and trouble though.