Hello everyone. I bought a used Volvo EC210LC excavator, from 2000, which has some problems. !! :-( Maybe you can help. 1. Right belt motor does not respond when stepping on the pedal. However, if you swing / bend slightly with the left joystick, it will pull well with about 25% force. !!! 2. In the right joystick, the piston for the bucket does not work, and it only has power when it is to lift the entire arm. and no force when pushing the arm into the ground / or lifting the machine, for example. As I see it, the right belt, the piston to the bucket and the two lifting pistons, all on pump 2, are closest to the engine. so maybe the pump controller doesn't work for pump 2. But then I just think it's strange that it seems to have full power when it has to lift the whole arm. !! But if pump # 1 can somehow deliver oil to lift the pistons, it makes sense why it can lift the whole arm !
Good day When you lift the boom while using the tracks you will connect both pumps to the track motors, from your description I suggest some seriouse trouble shooting befor you condem components.Begin from the motors and work backwards. Kind regards Uffex
I would suggest, first thing check your control pressure to both pumps. You have negative control on that machine. You should see about 30-35 kg at each control valve. As you stroke either lever or stick, you drain that oil proportionally to the stroke of the lever until you're at 0 . I don't think you have a problem in the MCV , your functions are working just weak. Boom up works, but requires 2 pump flow. So when you ask for boom, you're stroking both pumps. Pump 1 or 2 may very well be doing all the work. Let's not focus on tracks until you've reestablished your bucket control. Do you have gauges and the ability to T into the circuits? That's gonna make all the difference in the world.
Thank you very much for your response. That is, I must mount a gauges on each of these two hoses with a T, market in the picture?
This is the diagram, for bucket ! And I wrote wrong earlier. It's PUMP no 1, I suspect for not working!
That top circle, yes, the other , I can't really tell. But that top inboard hose is, I believe, where you want to see what is going on.
Hi ( Pump # 1, closest to the engine, which does not work ) It shows 200 psi (14 kgf) when the engine is idling and when you pull the handle the pressure drops to about 75 psi (5 kgf) (Pump # 2 (which works), between pump 1 and servo pump ) about 500 psi (35 kgf) when the engine is idling and again about 75 psi ( 5 kgf ) when pulling in the left joystick.
New picture
So, we have to start tracing the hose going to pump 1 from the main control valve. If possible, remove both ends of the hose and blow through. I suspect some debris may be trapped. Your signal should be equal to pump 2. In fact pump 1 , with only 200 psi should be partially stroked. The engine should be loaded a bit.
The engine is not loaded at all, :-/ You don't think I should remove the controller, and control if its okay ?
I don't like to open pumps and controllers until we've verified that there is no outside influence. Plugged / pinched hoses, plugged passageways etc stuff like that. Those pumps are very reliable, its usually something much more simple. Can we check pump standby pressure? What pressure is sitting at idle with no demands.
Pump #1 210 psi All the time Pump #2 400 psi standby and max 4500psi
Can you switch control lines between the 2 pumps?
I have tried that, didn't make any difference
No difference, where? Did the pressure follow the hose or stay at the regulator? If pump1 kept low pressure with pump 2s control line, then I would agree, it's time to go after the regulator.
I have attached a picture. Under the pumps is a valve block, with a solenoid valve inside. Can it affect the problem?
yes , kinda. That's a proportional control valve. check mA at the plug. It really only drops the displacement when engine is under severe load. Prevents bogging down and stalling of the engine. I don't think it's specific to front pump. I believe it acts on both. I'm still concerned with the oil available at the MCV to the pump controllers.
Hello again Now I just got time to try something new. I have changed the hoses on the two pumps, so that pump 1 now works as pump 2 and pump 2 as pump 1. Everything that did not work before, works now, the shovel etc. and conversely, all that once worked does not work now. So now I had thought about swapping the regulators around. ???? to find out if it is the pump or regulator that is teasing.
Are you saying that by changing hoses, the problem moved? If so, your pump is fine. Look to your hoses from the MCV going to pump regulators. Check for debris and obstructions. Physically remove the hose and blow through it from end to end.
Do you have a pattern change valve behind the cab?
It is the opposite I have moved the servo hose and pressure hose on pumps 1 and 2 , so pump 1 still does not work. But I'm probably pretty sure everything else works. except pump 1 and its regulator. And the reason the bucket now works is because pump 2 now supplies it!
Oh, I understand. Then yes. I agree 100. Yes , you basically switched identities between the two. Do you have a case drain filter available to you? I would remove it and cut it open. If there's a bunch of gold glitter, I would start considering a pump replacement. If its clean, I would just go after the regulator. Depending on your comfort level, I would suggest swapping the actual regulators between the two pumps. Have you looked at either filter yet?
What filters do you mean ??? (No, I do not have a case frain filter, yet )
There's the case drain. Large diameter spin on in the pump room. Then there's the return filter. It sits under the round plate in your hydraulic tank. Lift it out slowly. The oil passes from the outside-in . Look for anything, vinyl, metal, bits of this or that. That will give you an idea of where to start looking.
I have switched around the regulators now. And it did not help. But why can it not hold 500 psi, on pump 1 ?? Servo , pressure , Now pump 1 has had both regulator and control pressure changed. As I see it, there must be something inside pump 1, which may be leaking, and therefore the pressure is only 200psi and not 500 psi.
Did you find any sparkly stuff in the filter? I'm beginning to think that the yoke for the swash plate may be broken
No, I did not find anything in the filters
Is that the adjustment plate you mean?
You've isolated it to the pump. Bases on all your testing. No debris is at least good in the fact that you haven't scattered shrapnel throughout the system.
So now there is no way around taking the pump out of the machine,?
Yes, in a way. It ties the regulator to the rotating assembly dictating the displacement of the pump
I don't see anything else. If you've done everything you said, the problem can be nowhere else but the pump.
Hello again Then pump 1 is disassembled
Looks like the swash plate cradle and bearings took a hit. What about the rack that actuates the swash plate? Any scarring or scratches, did it feel loose? You're on the hunt for the slightest bits of dirt, debris or obstructions. Even the tiniest. You can't be clean enough.
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What about the side that faces the rotating assembly? Any scratches over there. The slippers look good, as best I can see in the first pic.
Here are all the parts 1/2
Here are all the parts 2/2
That last pic, I don't like it. I see a knick on the backside of the ball socket, scuffs on the spool and I dont think we should have exposed threads there.
Can you name the pic ?
This one
The exposed threads, Is because I disassembled it
Well, that makes sense, what about that knick on n the backside ?
I'm not there, cant see n feel everything. I am attaching a generic repair manual for Kawasaki pumps, please follow closely to see what I cant from here.
Thank you.
Hi I found the problem. A little sanding. Then the pump works again :-D In the picture, you can see before and after grinding with paste.
While the hand lapping may have certainly helped, I think you fixed it by completely disassembling and cleaning everything. The surface you showed isn't really a moving part. What matters most is you isolated the problem to the pump through diligent troubleshooting and corrected the issue.