loss of four way controls on mini excavator

[dave177]

Good Morning All,
Its my first post on here and hopefully someone will be able to help me out, .
I have a 2004 Hanix H22b mini excavator that was working fine until around a month ago when it started to constantly blow fuses and none of the 4 way levers worked, I could still track, use the blade and the hammer circuit. If I replaced the fuse it would blow again within a few minutes. We wen through the electric system testing as much as we could and replacing anything that seemed to not be functioning, including a relay that caused the fuse to blow and it seems to have stopped blowing now.

However the 4 way levers still do not work, I replaced a valve on the main spool block that cost me a great deal of money and have come to a bit of a loss with what to look for next.

Any help would be greatly appreciated.

Thanks Dave

[Muz]

Hi & welcome ... that machine may use hydraulic oil pressure to operate the servo system which is supplied by the pilot pump. The blade and tracks are operated by physical levers, but the rest isnt, so you should check the output pressure of the pilot pump before going any further

[d4c24a]

deadman

can't say i have ever been on one of those , does it have a deadman switch ,mechanical or electric

[dave177]

Thanks Guys,

I will have a look into the pilot pump tomorrow, any ideas what sort of pressure it should be running at?

It has a deadmans handle on the left hand arm however this turns off the whole machine instead of just locking out the controls like most other diggers.

[Muz]

Thanks Guys,

I will have a look into the pilot pump tomorrow, any ideas what sort of pressure it should be running at?

No idea I'm afraid .. you'll need to go to a dealer to find that out ... It might be the pump (usually a separate little gear pump) but it may also be something connected with it .. like a leak in one of its connected hoses , or a blocked filter. Ive seen a few pilot circuits that have a tiny gauze filter no bigger than your thumb contained inside what looks like a half inch hydraulic fitting .. the pumps are not that expensive (if its that) so dont panic .......keep us posted

[Mick-the-fitter]

Pilot supply problem!

Good Morning All,
Its my first post on here and hopefully someone will be able to help me out, .
I have a 2004 Hanix H22b mini excavator that was working fine until around a month ago when it started to constantly blow fuses and none of the 4 way levers worked, I could still track, use the blade and the hammer circuit. If I replaced the fuse it would blow again within a few minutes. We wen through the electric system testing as much as we could and replacing anything that seemed to not be functioning, including a relay that caused the fuse to blow and it seems to have stopped blowing now.

However the 4 way levers still do not work, I replaced a valve on the main spool block that cost me a great deal of money and have come to a bit of a loss with what to look for next.

Any help would be greatly appreciated.

Thanks Dave

I think your fault lies in the pilot valve, the solenoid which is activated by the dead man lever, supplies oil to the levers from the pilot pump, on the block is a similar solenoid which controls the fast track speed, if you change them around and change the plugs over, you will regain levers and loose fast track, and as a check when you press your fast track control the fuse will blow, (by a replacement solenoid to cure the fault)

[ianoz]

Welcome to the form Mick.
Good to see another helpful member joining the forum .

[Muz]

Welcome Mick-the-fitter I tidied up your post for what you wanted to quote , you just missed some tags in your dave177 quote... if ive missed anything just shout

[Mick-the-fitter]

Welcome Mick-the-fitter I tidied up your post for what you wanted to quote , you just missed some tags in your dave177 quote... if ive missed anything just shout

Hi Muz, yeh all seems good, hope that this has sorted the problem, I like a challenge, plant is my game

[Muz]

I like a challenge, plant is my game

I agree .. a good head scratcher fixed with some spanners and a bit of thought brings its rewards

[dave177]

Thanks for the replies so far.

Muz, been right through the parts manual and cant find any reference to a pilot pump, would there definitely be on this machine?

Mick - Would this still be the case even though the dead mans handle turns the machine off instead. There is one solenoid operated valve that feeds both controls. it is not located on the main block but a stand alone unit, would there be a way of bypassing/testing this without replacing the unit?

Thanks

[Muz]

Thanks for the replies so far.

Muz, been right through the parts manual and cant find any reference to a pilot pump, would there definitely be on this machine?

Mick - Would this still be the case even though the dead mans handle turns the machine off instead. There is one solenoid operated valve that feeds both controls. it is not located on the main block but a stand alone unit, would there be a way of bypassing/testing this without replacing the unit?

Thanks

well the levers are not mechanical are they ? if it is related to the shut off control then, anything fouling the mechanism? any contact switches not being made ? a picture would be good at this stage

[Mick-the-fitter]

well the levers are not mechanical are they ? if it is related to the shut off control then, anything fouling the mechanism? any contact switches not being made ? a picture would be good at this stage

Hi yes of coarse the Hanix has a pilot valve separate from the main block, if I remember location wise it's just behind the door when it is open, under the floor, Bypass is possible if you join the pilot feed hose to the supply hose on the out let from the block ( follow back a hose from a lever they are "T"d in at some point ) the pilot block has a third hose which returns to tank.
When the hoses are joined there will be pilot supply continuously, the dead man won't work, so use with caution, if this cures the fault you should replace the solenoid, if it doesn't change the problem, then you could be looking at pilot pump!
mick

[Mick-the-fitter]

Hi yes of coarse the Hanix has a pilot valve separate from the main block, if I remember location wise it's just behind the door when it is open, under the floor, Bypass is possible if you join the pilot feed hose to the supply hose on the out let from the block ( follow back a hose from a lever they are "T"d in at some point ) the pilot block has a third hose which returns to tank.
When the hoses are joined there will be pilot supply continuously, the dead man won't work, so use with caution, if this cures the fault you should replace the solenoid, if it doesn't change the problem, then you could be looking at pilot pump!
mick

The pilot pump could be called many things, in translation it could be called a primary pump, or just pump! I will delve through my Hanix schematics to see if I can find it

[Mick-the-fitter]

The pilot pump could be called many things, in translation it could be called a primary pump, or just pump! I will delve through my Hanix schematics to see if I can find it

Hanix call it a gear pump, it's the small pump on the end of the main pump running about 10 to 15 lpm