Steering Issue

[ms0115]

ASV
RC - 100 Posi Track
PIN: RSD00158
The right side track will move, but very weak forward and reverse. It is not the drive motor. Customer had it replaced prior to coming to my shop. Any ideas on how to proceed. Thanks.

 

[Acecadet]

Maybe you could try swapping the control lines from the joystick to the pump to rule out the control side. Any history on if metal was found in the filters before the drive motor exchange? Could also try pulling the relief valves and checking for debris.

 

[ms0115]

All I have is parts diagram, it does not tell me what relief or solenoid does what. Any help would be appreciated.

 

[92U 3406]

Test the pump.

 

[Acecadet]

I would start by swapping the control hoses I have marked. Swap them front to back, then see if your problem switches sides. Then I would remove the relief valves in the forward section of the pump. They are on the right side of the pump as you are sitting in the machine. There will be a total of 4 of them. The two in the most forward section are for the right drive. Check the reliefs for any bad signs. If nothing is obvious maybe swap the reliefs with the rear section and see if the problem moves. If none of that works you are going to have to plumb in a pressure gauge (6000 psi) to the drive hoses and have a look.

 

[Acecadet]

 

[ms0115]

Swapped the lines, made no difference.Going to check relief valves next.

 

[ms0115]

All 4 relief valves look good, no debris or broke springs. Moved them front to back , made no difference when test running. Where do I need to test and what pressures am I testing for? Thanks

 

[Arny L]

I found an online manual for this machine, there are 4 drive pump test ports, on opposite side of were relief valves are. Two at top and two at bottom. Not sure which is forward or reverse,or right and left. Manual says adapt your 6000psi gauge into one test port, In your case right side. Make sure machine is up against an imovable object, or tie track to bucket arms with chain. With hydraulic oil warmed up and full throttle, move joystick forward, this will force oil over relief, you should see 5500psi. If you dont see that, then check relief valves, but since you did that all ready, skip it. Which ever test port is showing low pressure, remove drive hoses at pump for the right side and cap hose and pump, repeat test, if you can get to relief, then pump is good, drive motor isnt. You can download this manual www.scribd.com asv rc 100 Hope this helps

 

[Arny L]

ASV 100.jpg sorry it double posted.

 

[ms0115]

I will check pressures tomorrow. But just a few thoughts. I have already swapped the relief valves around and it made no difference. Left track still works, right track does not and the motor has been replaced. Is there anything else controlling the flow? Thanks.

 

[Arny L]

Your asumming the new drive motor is good, it may not be. Thats why checking the pump pressure is critical. And by doing it as discribed, you can isolate the faulty component.

 

[ms0115]

Finally was able to get back on this project. We tested the pump. If you are sitting in the seat on the left side top rear port it had 1,900 psi. Top forward port had 100 psi. Bottom rear port has 3,300 psi. Bottom front has 200 psi. What is this telling me? Since one port can produce 3,300 and they are using the same pump. I down loaded a manual, but the quality is so poor it is not helping much. Any information will help.

 

[Acecadet]

They are not the same pump, there is a rear pump and a front pump. I think you are due for a pump pull and partial disassembly.

 

[Arny L]

So it looks like forward test ports low reading, is co-insiding with R side poor performance. That lines up with what Acecadet said earlier as well. Now if you remove hoses going to r side motor, at the pump. Cap hoses and pump fittings. Repeat pressure test, if readings come up to left side test pressures, or close, then the new motor is the problem. If it stays the same. then you have a pump issue. According to repair manual. I guess it comes down to which is more work, retesting, or pulling pump, which you might be heading in that direction anyways. The left side relief pressure is not in spec either.

 

[ms0115]

Does anyone know where I can get a pump break down?

 

[Acecadet]

Looks like a cat pump 218-6927 is the same. Maybe Nige could get you some cat sis info on that pump.

 

[Nige]

Looks like a cat pump 218-6927 is the same. Maybe Nige could get you some cat sis info on that pump.

You rang...........??

Unfortunately I fear you are going to be disappointed. Attached is the parts breakdown for 218-6927 but there are very few repair parts available for it. On the parts diagram you'll note "for field replacement order 307-3072". Now that pump does have a parts breakdown.......I just need to find it.

 

[Acecadet]

After some digging I have found that the pump you are working on is a rexroth A22VG. There is some information available around the web on disassembly and testing of this pump.

 

[Nige]

I thought they were Rexroth, just couldn't find the confirmation.
Attached the disassembly & assembly procedure for the latest iteration of the pump. Parts & procedure may vary from an earlier version