ASV 120 Hydraulic Issue

[Howie8812]

Hi, I'm wondering if anyone else has had issues with the hydraulics on their ASV 120. After about 20 minutes of running mine I'm unable to turn left. I took it to an ASV dealer and they said I needed to replace the tandem pump and both drive motors. It only has 1200 hours on it. The dealership was pushing to put new parts in but $25000 is a lot of money. I decided to have the motors and pumps rebuilt. I took them to a hydraulic shop and they tore them apart and can't find anything wrong with them. The dealer still thinks they're the problem and said they don't know what else it could be. They tested the pressure before they took it apart and said it was low. There was no metal found in filters. Theyre back to pushing me to buy new parts so they can get it out of their shop. I would hate to spend all that money if its not that.. Any thought on what else could be the issue? Thanks for taking the time to read this.

 

[8V71]

Did anyone try swapping the LH track pump port reliefs with the RH drive pump reliefs or were they replaced when the pumps were rebuilt?

 

[Tree Mulcher]

I agree with the above.

If the machine runs normally for the first 20 minutes, it's not a pump failure in my experience. Furthermore, you had no metal in the system. Pumps don't typically reassemble themselves when cold.

How is your charge pressure?

If you can get a repair manual it may give you test procedures for the pumps, reliefs, valves and associated actuators. Hopefully new ASV manuals are better than the older ones I worked with.

Experiences like yours are why I don't trust or use dealers for repair work anymore.

 

[River Fluid Power]

If your hydro has electronic displacement controls they could easily be your problem. Have you tried forward and reverse on each side by themselves? Maybe reverse on the left side or forward on the right side is the problem. You could try disconnecting all four of the electrical connections on the pump controls and check voltage when the controls are actuated. Like Tree Mulcher said, it could possibly be charge pressure related. Also, not all hydraulic shops are the same. I’m not saying your hydraulic shop did, but I have seen shops overlook issues.

 

[Tree Mulcher]

If your hydro has electronic displacement controls they could easily be your problem. Have you tried forward and reverse on each side by themselves? Maybe reverse on the left side or forward on the right side is the problem. You could try disconnecting all four of the electrical connections on the pump controls and check voltage when the controls are actuated. Like Tree Mulcher said, it could possibly be charge pressure related. Also, not all hydraulic shops are the same. I’m not saying your hydraulic shop did, but I have seen shops overlook issues.

I agree. Reversing the wires on the tandem drive pump actuators/solenoids should be an effective diagnostic method to isolate the problem to the hydraulic system or electrical. You may get some codes from speed sensors if it has them unless you also switch that wiring. Hopefully the harness will allow this otherwise you might need a jumper harness.

I have not run any of your specific model and have no books to reference.

From my previous dealings the engineers at the ASV (I had extensive issues with a new machine and incompetent dealer) factory will talk to you if you need technical assistance. They sure do appreciate if you have already followed the manuals to diagnose on your own.

If you haven't already get a schematic of the hydraulic system.

I have schematic drawing for my machines. both electrical and hydraulic. I take the electronic file to an architect and get them to print them on large plans paper. really can help to study in this type of situation.

 

[Welder Dave]

I would bet there aren't a lot of ASV's sold by individual dealers so they don't have a lot of experience working on them or repairing hyd. components. It's easier to just replace everything than have to try and diagnose it. There could be really poor factory training as well. Unless somebody sabotaged the machine it's not likely you need new pumps or motors at only 1200 hours. I'm guessing it's out of warranty?

 

[Howie8812]

Sorry for taking so long to reply and for your feedback. Here's an update on where I am now. I ended up listening to the ASV mechanic and replaced the tandem pump and both drive motors. They said when they put it back together that all the pressures testing good now. I took the machine home and used it for a half hour and guess what, its doing the same thing as before. Once its warmed up it doesn't want to steer or move. I can't even get up a small incline with it. When trying trying to drive forward and move the bucket at the same time the bucket will eventually go up but will need to build up pressure and then randomly jerks upwards. I spent $22,000 on fixing it and its the exact same. I asked the ASV dealer if it could be the charge pump but he says it can't be because the pump and drives have pressure. While the machine is cold it does but its evident he didn't run the machine long enough to know what the issue was. I got the service manual now and it says to test the charge pump first and then the pressure relief valves before the tandem pump. They never did that. They just pressure tested the pump and drive motors. If the charge pump was bad wouldn't that cause the tandem pump and drives to have low pressure? I'm taking the machine back to the dealer today and making then do the tests in the exact steps the manual shows in front of me in hopes that provides some clue on what is wrong with it. If anyone reading this has a similar problem don't listen to the dealer. Do some research and make them give you the pressure reading for each component before replacing any parts. If anyone has any other helpful tips I'm open to suggestions. Thanks

 

[Welder Dave]

It obviously wasn't what they replaced. I'd be wanting my full $22K back! If the dealer can't even follow the factory troubleshooting guide, I wouldn't trust them to even change the oil. Hopefully you don't have to get a lawyer involved. Good chance your old motors and pumps didn't need replacing.

 

[Welder Dave]

Double post

 

[Arny L]

Is there not a monitor panel on that machine that you can access stored and active codes.

 

[Tree Mulcher]

Unfortunately, in my experience I would not be surprised if the dealership tried to blame you for their incomplete diagnostics.

Make them give you your original parts back. You now have spares if they did not contaminate them. If uncontaminated and lines capped should have no problem storing.

 

[Welder Dave]

They should show you exactly what caused the problem. Words mean nothing. They should show you the physical damage and why the pumps, motors or whatever couldn't be repaired and why everything had to be replaced. If the components are really bad it can be cheaper to just replace them. Also if they are that bad, everything thing else that has hyd. fluid going through it needs to be throughly flushed and removed if necessary to clean the system.
I think it's more a case of a dealer not having enough experience to diagnose the problem and it's easier to just replace components.