loss of four way controls on mini excavator

[dave177]

Thanks for looking that up for me guys, I have a day in the workshop tomorrow so I will see what I can turn up with it. I will also try and put some pictures together for everyone to see

[dave177]

Finally managed to have a few hours working on the machine. although I think this has left me with even more questions. I have taken a few pictures, if anyone could help me identify what they are so I can cross reference the manual it would be greatly appreciated. One is what I am guessing is the gear pump and the other is a solenoid valve that I'm not sure of its function.

I have a pressure tester arriving this week so hopefully it will give me some better insights

Thanks

[Mick-the-fitter]

Ok

Finally managed to have a few hours working on the machine. although I think this has left me with even more questions. I have taken a few pictures, if anyone could help me identify what they are so I can cross reference the manual it would be greatly appreciated. One is what I am guessing is the gear pump and the other is a solenoid valve that I'm not sure of its function.

I have a pressure tester arriving this week so hopefully it will give me some better insights

Thanks

The first picture, from what is visible looks to me like the slew motor from the top, the gear pump is found at the end of the main pump, bolted to the end of the engine.

The second picture is the main spool block, and to the right of the picture there is I think the main relief valve cap!

There is between the pump on the engine and the spool block, a pilot valve block which will houses the pilot solenoid.

Mick

[dave177]

Thanks Mick,

Ill do a bit more hunting tomorrow and see if I can shed any more light on this.


Thanks

[dave177]

Had another little play with the digger yesterday as I managed to get my hands on a pressure tester.

I can only find 1 pump on the machine, joining the engine on the L/H side, it has 1 large low pressure hose (Feed?) and 3 high pressure hoses all running at 2-300 psi depending on rpm.

I have tested the pressure coming into the pilot/valve solenoid (Possibly) and it was sitting a 120-200 psi depending on RPM.

This solenoid then splits out and has one feed into the turning motor that I couldn't test as I didn't have the adapter but there is fluid coming out of it. The other side of the solenoid was putting out 35-40 psi straight out of the block, this then splits off and goes into both sets of 4 way levers.

The pressure coming out of the valve doesn't change if I disconnect or reconnect the electric feed into it. I will have to wait until I can pick up an adapter but due to this difference in pressure I am thinking it is going to be the faulty valve solenoid?

Any comments on the above would be great as I am just guessing for the most part on this.

Thanks

[Mick-the-fitter]

Had another little play with the digger yesterday as I managed to get my hands on a pressure tester.

I can only find 1 pump on the machine, joining the engine on the L/H side, it has 1 large low pressure hose (Feed?) and 3 high pressure hoses all running at 2-300 psi depending on rpm.

I have tested the pressure coming into the pilot/valve solenoid (Possibly) and it was sitting a 120-200 psi depending on RPM.

This solenoid then splits out and has one feed into the turning motor that I couldn't test as I didn't have the adapter but there is fluid coming out of it. The other side of the solenoid was putting out 35-40 psi straight out of the block, this then splits off and goes into both sets of 4 way levers.

The pressure coming out of the valve doesn't change if I disconnect or reconnect the electric feed into it. I will have to wait until I can pick up an adapter but due to this difference in pressure I am thinking it is going to be the faulty valve solenoid?

Any comments on the above would be great as I am just guessing for the most part on this.

Thanks

Ok ok the pilot pump is the small block on the end of the main pump, in your photo the block on the left hand side, the hose you can see in the photo coming out of this pump is going to the pilot valve, the feed to the slew motor will be the slew brake feed. If you have found where the levers are teed off then take a hose from the pilot pump, where the hose comes out to the pilot valve, and connect it to the tee for the levers, if you have ops then you need a new pilot valve solenoid!

Mick

[Muz]

Bear in mind too, what I mentioned earlier, that, some pilot circuits have filters in line somewhere in the circuit. You need to identify that there is/isnt one so that can be removed from equation