hydraulic problem

[rewdan]

Hi, I have a Libra 1.6 ton mini digger, im having problems with the hydraulics.

Tracks, boom, dipper and bucket all work fine. Dozer blade, slew (360 spin) and the speed up button are all very slow, dozer blade can't lift the front of the machine up.

However for eg. if I operate the boom or move the bucket at the same time as spinning 360 degs, the spin returns to normal speed. Same with the dozer blade, can't lift itself off the floor unless I move the bucket.

Any help or advice anyone can offer would really be appreciated.

Thanks

[Muz]

Sounds like a main relief valve is not working correctly .. might have some dirt there or some other fault causing a valve to not open properly

[rewdan]

I read this on another post-

I'm not sure what type of hydraulic pump you have on your machine but it could be that. If its a 2 stage or 3 stage pump you'll find each segment of the pump operates different operations. (dipper and bucket one segment, blade and left track another segment etc) Try using one of your slow operations and pulling say the blade lever at the same time until it pressurises? If it has more power it will probably be one stage/slices of your pump is cracked, worn or seals have gone...

I have a 3 gear pump, could this be the problem?

The engine did overheat a week ago which means the hydraulic oil must have got hot too. All help appreciated

[rewdan]

In case someone else has a similar problem


ok, I think it's solved. I went out this morning, started it up and all hydraulics were working normally. Hydraulic fluid cold. The cooler for the HF is bolted to the engine radiator. So big sigh of relief as I am hoping the Hydraulic side is all ok.
Onto the next problem, very small water leak but enough to drain the rad over a day of working. Turned out to be a constant drip from the rad overflow by the rad cap. Bit of google and looks like a head gasket or cracked block ffs. Pulled the thermostat and checked it, working fine. Decided it was the head gasket or something worse so decided to jet wash the engine to take a better look at whats involved. After washing it, ran the engine and applied air to blow all the water etc away. The rad was still overflowing with the engine running.
Got the air on the rad and tons of dust came out of the fins, kept going for about 5 mins and suddenly the rad overflow stopped dripping, now running as it should.
In the course of two days I went from...New hydraulic pump to engine rebuild, machine out for weeks etc. Turned out it just needed the rad cleaned. I woke up pissed off and by lunchtime I'd solved it so was over the moon. Went out and had a few beers!

[Muz]

I

The engine did overheat a week ago which means the hydraulic oil must have got hot too.

Thats not the case .. the hydraulics are a separate system

In case someone else has a similar problem


ok, I think it's solved. I went out this morning, started it up and all hydraulics were working normally.

Glad you got it working ok .. but it doesn't explain why you were having the hydraulic problems you described earlier .. perhaps it was something that cleared its self ?