Case 580 ck extendahoe Hydraulic

[Bookumdanno]

A friend has the backhoe and had pump go bad. I got him a new replacement pump. I pulled the old TRW pump apart and found the pressure plate and seal had a 1/2 inch chunk missing. He just called and said pumps bad. I think it's a problem with where the old pump parts went. What should I have him or us check? Could the loader control valve be blocked?

 

[alrman]

Welcome to HEF @Bookumdanno !
Firstly, don't assume anything. Go & see exactly what the machine is doing.

The pump draws oil from suction & delivers to the control valve, so anything debris a damaged pump makes all flows to the valves.
I would think there may be a relief valve issue with this machine, especially if it has just had a pump failure.
Possibly some trash is holding it open & hence the machine will have no hydraulic power.
As part of a pump replacement, you should really replace the hydraulic filter & test the main relief pressure.
We are here to help.

 

[Juskatla]

On the 580 CK, the pump high pressure side goes to the loader valve and then on to the backhoe. Return is from the backhoe to the loader valve and then through the hydraulic filter and back to the reservoir.

Loader valve has the pressure relief valve in it and would be the first place to look. I'm no expert, but removing the hose that connects to the pipe from the pump would give a look at the valve inlet. Don't operate any spools to keep any debris out of the cylinder circuits. Consider looping the backhoe hoses to keep the issue at the loader valve if its not already in the backhoe valve.

Keep us posted on the outcome...

 

[Bookumdanno]

Well before I could help, he pulled the loader valve out and took it to a hydraulic repair shop. They just called him and said the valve is bad and can not be repaired. I guess I'll start looking for a replacement for him. Any ideas where to find a valve? Thanks

 

[Bookumdanno]

I started doing search online and found numerous places for used parts. Prices went from $450 to $997 used to over $2000 for new valve. I told him to go for the $450 one. There's only going to be other parts to spend his money on. It's an old backhoe. Will see what happens when this part comes in.

 

[Juskatla]

I would suggest that you call Dale Weiss at Tractorstuff. He will likely have a used valve for you. His prices are reasonable and he is familiar with these older tractors. I got all my 580CK rebuild bits and pieces from him. Good hunting...

 

[Bookumdanno]

Well he got a used loader valve online and got it installed. Attached a pressure gauge to test port. Full throttle there's no pressure, roll the front bucket back full and pressure only goes to 800 lbs. Tried adjusting the main relief valve and no change. I think maybe the new pump might be bad. Am I wrong or is there something else to try?

 

[alrman]

Don't you hate that.....
Did you try swapping the main relief valve from the original control valve?
No rags/tape etc. been left in the suction hose between the tank & pump during install?
You would have to trust a new pump..... the only way to test it is with a flow meter.

 

[Vetech63]

Looks like you don't have enough pump flow to create the pressure. There are aftermarket pumps available at a lot less cost than the dealer. I have installed a few and have had no issues. Good luck!

 

[Bookumdanno]

Well seller of pump issued an RMA and prepaid shipping label. Once they got bad pump, a new one was shipped out. My friend installed pump. He said it killed his engine once but he had pressure. I'm not sure what the pressure is, first time he said 3000 psi later he said 2000 psi. I don't think he can read the gauge. He said the loader moved fast and the hoe worked good to the right but was slow to the left. Did he go thru the procedure to bleed all the air? I don't know. I told him how to do it. He checked pump and found it had busted the front engine support that the pump attaches to. He tried to do a spot weld at the left mount hole. When he looked later the entire top part from center line of both bolts on pump up broke off. I gave him a list of sellers for used parts. When I looked at support I found it was missing the bolt and washer that attaches it to the frame on bottom and I couldn't feel the bottom left bolt. When he gets this replaced I told him we need to adjust the main pressure relief valve. I also tried to explain the procedure for aligning mount to engine. This is WV and he doesn't understand ( he only has a 6th grade ed. ). I sure hope when the part is installed it's close for his sake. Hopefully I can be there to see what's going on when he gets it back together.