hydraulic valve problem?

[dig-dug-dan]

Bit of an unusual one.i have mini crushers I hire out, as well as a, tracked skip loading dumper. If anyone is familiar with the tcp hit500 skiploader, it has two speed tracking. When you push the levers forward, it drives in slow, then you can press a button and it jumps into faster mode, by an electro magnetic valve that diverts flow.

anyway, it now will not move when I oush the levers foward at all, unless I push the levers and then press the high speed button!

the oil is flowing through the system ok, just seems to not work in slow mode. If imjack the machine up, I can get the track to move not under load.

I can only assume a blockage in the control valve?

the manufacturer has never heard of this problem before!

[cornish wood burner]

Could be a leakage rather than a blockage.

If you had a leakage in your slow speed circuit then the extra oil in fast mode would overcome the leakage enough to move the tracks but the power would be down.

Might be useful to check pressures at various points.

[dig-dug-dan]

I have no oil leaking out anywhere.

what is interesting, is that the oil comes out the pump, and into a 4 way valve block. When the crusher jaw is not working, the oil simply flows in and out, but an electromagnetic valve diverts the oil within this 4 way block, to make the ram move back an forth. This valve block had a split in it, so I replaced it, and its since I did that, that this problem has occured!

[cornish wood burner]

I have no oil leaking out anywhere.

what is interesting, is that the oil comes out the pump, and into a 4 way valve block. When the crusher jaw is not working, the oil simply flows in and out, but an electromagnetic valve diverts the oil within this 4 way block, to make the ram move back an forth. This valve block had a split in it, so I replaced it, and its since I did that, that this problem has occured!

I was thinking of an internal leak or oil short circuit. Sounds like it is connected to the replacement valve or the installation of it.

[dig-dug-dan]

Starting to think that too. Crusher works ok. The valve block I replaced originally came out the machine, it too had a splt which a local ally welder fixed.

my only other thought is if tnere was something inside it when I connected it up, thats now found its way into the valves for the tracks

[cornish wood burner]

Could you bypass the offending valve and divert the oil directly to the track circuit?

[dig-dug-dan]

Could you bypass the offending valve and divert the oil directly to the track circuit?

 

I tried, but the couplings on the pipes are too bent. I need to get a pipe made up to do it. Might be worth a shot to rule out the replacement valve.

[cornish wood burner]

I tried, but the couplings on the pipes are too bent. I need to get a pipe made up to do it. Might be worth a shot to rule out the replacement valve.

 

That would be my approach if possible before spending a lot of money on a valve.

Perhaps the crack has internally bridged between circuits or the welding has distorted the body enabling oil to bypass a seal/ valve.

[Breezeblock]

pull the solenoid valve out and have a look at it check that the o-rings on the spool are complete as it could be leaking in to the return it sounds like a massive internal leak

[treequip]

Starting to think that too. Crusher works ok. The valve block I replaced originally came out the machine, it too had a splt which a local ally welder fixed.

my only other thought is if tnere was something inside it when I connected it up, thats now found its way into the valves for the tracks

 

If I am following this, you have replaced a busted valve with a repaired valve and now it wont work????

 

Buy a new valve, it will be better than the alternative which is wasting time messing with a busted valve. Welding valves back together is a new one on me.