ASV RC85 Issues

[Amadeus3]

Hi All, I’ve been creeping on the forum for a while but this is my first thread. I just bought a 2006 ASV RC85. It has a couple issues that I’d like to address and am hoping some folks on here can offer advice.

Issue 1:
The drive controls are sometimes slow to respond. What I mean by this is the joystick inputs don’t immediately transfer into desired machine movement. Going from forward to reverse or reverse to forward is slow and also going from left to right or right to left. I’ve read that a resolver block for the drive pilot controls was an issue on these units and the cats. I will explore that with the dealer. Any other thoughts?

Issue two:
The auxiliary low flow circuit seems not to hold pressure. I have a grapple bucket and it will open and close the grapples fine with what seems to be appropriate force. But when open they will immediately begin to slowly fall down one at a time. It takes about 5 seconds for each arm to fall. I tried bleeding those cylinders because it felt like there was air in there when I lifted them by hand. No dice.

I’m assuming that section of the loader valve is leaking down? I don’t have a pressure gauge but can get one. I assume that circuit should reach 3300psi or whatever pressure spec is and hold it for a while in both directions right?

Worst case is that valve rebuildable in sections? It’s a Husco valve but my service manual provides no info other than the functions of each section. Can I just pop off the top circuit and replace or rebuild? Or is there an easier solution?

Thanks for any help and input.

 

[f311fr1]

Are you sure the grapple cylinders are not leaking by the piston seals? You can down load manuals from Track Loader Parts in GA. There is an Operators Manual, Parts Manual, and Service Manual. If you contact ASV direct with your machine and S/N they will send you an electrical and hydraulic schematic. You also might want to ask for the Perkins engine S/N if it is not on the valve cover. You will need it later for engine issues. Check out Bair Products for alternative under carriage parts. Vine and Branch equipment in WA is also an excellent parts source.

 

[f311fr1]

The valve sections have load check valves and relief cartridges. These parts should be available. See schematic

 

[Amadeus3]

Awesome thanks! Yeah I’m not sure the cylinders are leaking. The grapple doesn’t have a lot of hours and I thought it would be unlikely both cylinders would be bad. I do have a neighbor with a skid steer and was going to try the grapple on his machine and see if I can isolate the issue to my machine or the grapple. We shall see.

So far the engine seems fine. It has 3000 hours but starts immediately and runs good. Does that engine have a bad reputation? I know it’s the same as the cat 287b and Perkins has some bad press, but any specific issues?

 

[Amadeus3]

Also, if I’m reading that diagram correctly the part number 0201-649 is the relief/check valve I would need to replace to stop leak down?

 

[f311fr1]

Swap the reliefs side to side and see if the problem moves. I also have attached a filter list . My RC100 got new injection pump and injectors at 2800 hours. My RC85 got injectors at 2400 hours. It is important to keep your filters up to snuff. I change mine every 250 hours, or as needed, rather than the factory 500 hours. It is also important to keep your radiator cleaned out and keep your coolant level topped off. I also remove all the pans at each 250 hour service and wash out the bottom of the machine.

 

[Amadeus3]

Good to know. Thanks that’s great info, really appreciate it.

Do you have a hydraulic diagram of the drive controls? The one I have doesn’t show much besides the pilot lines and joystick. Trying to identify this resolver block and how much that might cost.

 

[f311fr1]

ASV refers to the section below the joystick handle as a logic block. I replaced one once and it solved the problem. The second time I tried it on another joystick it did not solve the issue. They cost about $400 and the complete joystick is about $850.00. They are made by Rexroth. I have attached some RR info. BTW I was unable to purchase a replacement thru RR. So ASV has a lock on the replacement. You need to verify your pilot pressure before you change the joystick. The fittings in the bottom of the joy stick should be replaced if you replace the joystick. IIRC the fittings are BSPP male to FF oring male. Take pictures and mark the lines/fittings.

 

[Amadeus3]

You’re the man! Thanks! I’ll verify pilot pressures before ordering anything. I also read about people flushing out the pilots and having that fix the issue so I might try that first before spending any money.

thanks again for the info and advice. I really appreciate it.

 

[Amadeus3]

I put a gauge on the aux circuit today at the QD fitting. The gauge only went to 3000psi so it would bottom the gauge no problem. However as soon as I let go of the momentary switch pressure would drop right back to zero psi. I didn’t have the right fitting to test the other side but assume it’s similar. This machine was used to plow snow so probably saw a lot of action on that valve.

Am I correct in assuming the circuit should hold pressure once the momentary switch is released? Similar to other functions.

Looks like I’ll need to replace the pressure relief valves. Track loader parts has them for $190 each.

 

[Amadeus3]

Well I replaced the relief cartridge and it made no difference. I also got a new grapple and it still falls down immediately.

Is there a solenoid valve somewhere that controls pressure in the circuit? I’m sort of at a loss where to go from here.

 

[Amadeus3]

F311fr1 I realized in your initial response you mentioned load check valves and relief valves. I replaced the relief valve but can’t see where the check valves are. I don’t see them on the schematic. Is there a load check valve for the low flow auxiliary circuit?

 

[seville009]

Regarding the slow movement (forward, reverse, etc), I have a 2009 ASV PT50 I purchased new, and it’s always a bit slow changing directions. It’s not like a zero turn mower, for example, in its directional responsiveness.

it will respond quicker, of course, the higher your rpms are. The engine and hydraulics being warmed up helps too.

The only attachment I use the auxiliary hydraulics for is a snowblower, but I don’t use the joy stick buttons to run it, but rather just lock the hydraulic flow on.

 

[f311fr1]

Is the push to drain valve at the top of the aux QD block leaking back to tank? It drains directly back to tank through the case drain line. You could take the hard line loose on the back side of the case drain QD fitting and plug the hard line and cap the fitting to eliminate that as a leak down source. You can go to TrackLoaderParts.com and down load a parts manual. They do show the spool as a separate part.

 

[f311fr1]

Does the grapple bleed down if you raise it and then disconnect the down side QD trapping the oil. If it does the piston seals are leaking down

 

[old timer]

I'll jump in and see if I can help.....
Drive lag problems are usually related to low charge pressure. First check the pressure near the filters, should be 625 to 700 psi. Then check at the hst pump, should be 400 to 450 psi.
Looking at the grapple drift, I would look at the control side (pilot generation block) just under the floorboard under your feet (access by taking off the skid plate) SV5 controls the 2 way hydraulics.
Hope this helps, stay safe

 

[Amadeus3]

Thank you all.

The grapple cylinder doesn’t leak down. It stayed up for a week.

I was talking to the local Cat dealer and they mentioned the steels in the aux switches can wear and cause the solenoid valve to drift.

I’ll check pressures for the drive issue. It’s not terrible and I can live with that for now. I really need to get the grapple/aux pressure issue fixed.

It looks like SV5 and SV4 are the same part number. I might try swapping those and see if anything changes. Anyone know what SV4 controls?

 

[old timer]

SV4 controls the hi flow spools

 

[FRGrading]

Thank you all.

The grapple cylinder doesn’t leak down. It stayed up for a week.

I was talking to the local Cat dealer and they mentioned the steels in the aux switches can wear and cause the solenoid valve to drift.

I’ll check pressures for the drive issue. It’s not terrible and I can live with that for now. I really need to get the grapple/aux pressure issue fixed.

It looks like SV5 and SV4 are the same part number. I might try swapping those and see if anything changes. Anyone know what SV4 controls?

Did you ever find out what the issues was? I just bought a 85 and its doing the same thing.

 

[Tones]

The switch on the control handel can stop centring and cause attachments to drift, also the solenoid on the hydraulic control block can be the problem. They are what's known as perportional switch and solenoid.