New Member, New Owner of a 425

[Frank Sorbello]

How many hours were on the machine when you had the pump and motor failures? Any idea what caused them to fail?

 

[JGZahn]

I found the serial number on the 425, the tag was painted over but a little paint thinner cleaned it off. The ID# is 18024, any idea what year it is? It's currently showing 1341.5 on the hr meter. I have no attachments for it so once I get it mobile again they'll be next on my list...

 

[JGZahn]

Frank,
The shop said it looked like contamination, either dirt, water or possibly cavitation damage to the pumps. The main problem is the tram pump, the other pumps are easier to source parts for. I haven't pulled the wheel motors yet, so if one of those failed could that contaminate the oil and damage the pump? I did some work on this unit last year, it had blown a head gasket so I had the head off and machined. After the head work it ran great and I did some light earthmoving and tilling before it was picked up by the owner, a friend of mine. He got a new Power Trac when the pump went on this one and gave me the old one.

 

[MossRoad]

Yes, a damaged wheel motor 'could' cause the tram pump to fail. As I understand it, the tram circuit is a closed loop system. The oil circulates through the tram pump, then the two wheel circuits, then back to the tram pump. Forward and reverse flow in those circuits, of course. Then there is the charge pump which makes up any oil in the tram circuit that is lost through leakage back to the tank. I forget where the hydraulic cooler resides in all of this. I think the hydraulic filter may be on the makeup (suction) side of the tram pump. That's the only oil that gets filtered. The steering/FEL/aux PTO circuit doesn't get filtered.

 

[KMA]

Wheel motor rebuild kits are fairly inexpensive, and if you already have the shop rebuilding your tram motor you might consider having them do it all. (or do it yourself if you prefer)

I guess it would depend on what the damage is...

 

[ponytug]

Since the drive circuit recirculates the oil amongst all four motors and the drive pump, if you are rebuilding some of the pumps due to damage, it is reasonable to expect that the other pumps have some damage as well. At a minimum, I would flush the drive circuits to flush out any filings/crud out before you put new/rebuilt motors back into the circuit.

All the best,

Peter

 

[JGZahn]

I figured I'd pull all 4 motors and have them gone over, flush the lines and tank and start fresh. I sent the pdfs for the NV10 pump to the shop, turns out it isn't the same model. I called Power Trac and they gave me their part number which doesn't cross over to a Bondioli #. I guess I'm back to square one on the tram pump unless the shop can ID it.

 

[woodlandfarms]

Is there another Hydraulics company in your area? I only ask because in our area with all the logging there are lots of companies, and when I went in two companies didn't know what it was, but the third idented it and fixed it right away (it was not a PT part, sorry).

 

[toy]

Hi All,
I have recently gotten a Power Trac 425, it had a failure of the main pump and at least 2 wheel motors. Power Trac has given me prices on repair of the pump, replacement prices on the motors as well. I have a local hydraulic shop inspect the pump. The shop said it's a Bondioli & Pavesi pump which makes sourcing the parts difficult. They can repair it but need the model number of the pump because there is no tag or ID# attached to it. Has anybody tried having one of these rebuilt other by Power Trac? Has anyone found a bolt-in substitute pump? It's a neat little unit, I had the chance to use it last year w2hile it was still mobile to move a little dirt and use the tiller attachment and would like to get it back up and running by Spring, but I have time to explore my options for repair/rebuild/replacement. Thanks for any info you can provide.
JZ:newhere:

Has the hydraulic shop did anything to make sure that the pump and wheel units are actually down or did they just get a quick look see without tearing it down? What was the symptoms of your machine before it completely broke down and what is it doing now? Is your problem just the tram or is all of the functions of the hydraulic system down? It seems odd that you would loose main pump and two wheel motors at the same time, not saying that it can't happen but it would make me slow down a bit and look a little closer at what is going on. Those pumps are quite expensive to not do a little trouble shooting on it first. Since you have had your machine a while you probably already know that if you have the steering cut all the way and still trying to cut the machine steeper then you will lose the up pressure on your loader arms. If it is a tramming problem only then maybe it might be in the tram pedal valve or the linkage. Did the machine make any strange or unusual noises just before it went down that would lead you to think that something went through the pump and destroyed it. Does your machine sound like it might be cavatating making it sound like it is low on oil or a suction line stopped up? On the tramming valve the pin that holds the tram pedal might have backed out some. If the pin is in like it should be then maybe the valve spool on the tram pedal might be stuck in one direction. When you work the tram pedal does it seem like in one side the pedal is not hitting any thing [goes in and out without any resistance on one side] while when you push it in the other direction it feels like you hit a little resistance like it is pushing in the valve on that side, if that is how it is doing then maybe the tram valve is stuck. If the spring in the relief valve has a broke spring or has something keeping it stuck open that can cause you to loose hydraulic problems. The relief valve might have backed out some that would cause problems also. If you don't know what you are doing and have a gauge to watch the pressure if doing any adjusting then don't do it, cause it can be dangerous. Hope something in my ramblings might help you, there was one of the members a while back had a tramming problem only wanted to tram one direction and his machine was out in the woods stranded for a long time and his problem was the tram pedal valve. Hope you get it fixed without much expense and very much down time.

 

[toy]

JGZahn I assumed that your machine was only a year old with low hours but after going back and reading the rest of the posts it is my understanding that the machine has several years of service and that changes things, it might be all of the things you mentioned went out a once. I would still check out things a little, if it has a hydroback then someone else might know more about that.