Hitachi EX15

[nic9]

Hello, this is my first post and I'm hoping someone out there can help as I'm in trouble!
I have an old Hitachi EX15 which I'm using for some fairly light landscaping work on my property. It's been working fine, but yesterday it stopping swinging to the left. Everything else works ok (reverse travel is a bit slow and needs max revs). I've swopped the left and right swing hoses on the control lever so prove the problem is not there. I've now run out of ideas, can anyone suggest where to look next?

[v8druid]

is it servos?
if so swapping hoses at the control lever could have all sorts of results. ...... I assume it has made no difference??

It's an odd fault for sure?

as it's the same motor with a reversed flow for slew left/right, it's unlikely to be the motor ?? More likely to be a control issue

[nic9]

Hitachi EX15

is it servos?
if so swapping hoses at the control lever could have all sorts of results. ...... I assume it has made no difference??

It's an odd fault for sure?

as it's the same motor with a reversed flow for slew left/right, it's unlikely to be the motor ?? More likely to be a control issue

Thanks for your input.
When I swopped the hoses all that happened was that I could slew right by moving the lever left, still nothing in the other direction. At least it showed that the left swing valve was working.

When I try to swing left there is no change in noise from the engine or anything else, and the control lever feels dead, it just seems like absolutely nothing is happening.

[v8druid]

Thanks for your input.
When I swopped the hoses all that happened was that I could slew right by moving the lever left, still nothing in the other direction. At least it showed that the left swing valve was working.

When I try to swing left there is no change in noise from the engine or anything else, and the control lever feels dead, it just seems like absolutely nothing is happening.

the left swing servo unit is functioning ..... and also the right from when plumbed correctly.
you need to swap the hoses over from the main valve block .... either at the block or at the motor.

if it slews left ..... but not right, it's either the servo control at the main valve, or the main valve itself.

first port of call if that happens would be the servo actuator on the valve block ..... much easier than delving into the main block and almost certainly the issue
probably just not actuating the main spool.

let us know how you get on

[nic9]

the left swing servo unit is functioning ..... and also the right from when plumbed correctly.
you need to swap the hoses over from the main valve block .... either at the block or at the motor.

if it slews left ..... but not right, it's either the servo control at the main valve, or the main valve itself.

first port of call if that happens would be the servo actuator on the valve block ..... much easier than delving into the main block and almost certainly the issue
probably just not actuating the main spool.

let us know how you get on

Thanks again for your input. The picture shows the nightmare below the seat, the hose with the red tape is the left swing from the control lever (front of cab is to left of pic). Are you saying there is a servo somewhere in there that I can remove without taking the whole lot out? I'll try swopping the motor hoses first though.




controlvalve2.jpg

[Muz]

Its not some physical problem, like the slew transport pin dropped down (if it has one) ? can you go 360 to the right but nothing at all on the left ?

[nic9]

Its not some physical problem, like the slew transport pin dropped down (if it has one) ? can you go 360 to the right but nothing at all on the left ?

Yes, it goes all the way round to the right but nothing to the left. Nothing at all happens when I try to go left, no noise or change in engine noise and the lever feels dead.

[Muz]

Ok .. what about a pilot mechanism problem .. lift the boot off the left control lever , are all the pilot valves sticking up ? mess about with the left hand one that controls the left slew ?

[v8druid]

Ok .. what about a pilot mechanism problem .. lift the boot off the left control lever , are all the pilot valves sticking up ? mess about with the left hand one that controls the left slew ?

he's swapped the pipes over Muz to prove the pilots on the stick

I'd be swapping pipes on the motor .... looking at that rat's nest under the seat

trying to remove a servo cylinder (or two) off the main block'd be a 'kin 'mare in that lot

swapping motor pipes'd at least prove motor functionality .... then it'd either be .... servo / main valve fault, at the block ...... or crushed hose even

[v8druid]

Hello, this is my first post and I'm hoping someone out there can help as I'm in trouble!
I have an old Hitachi EX15 .........

this old ???


or more this age?

[nic9]

Thanks for all the continuing input.

Not sure which hoses I should swop on the swing motor, can anyone advise?
swing.jpg




By the way, this is the offending machine:

ex15.jpg

[Muz]

Be P1 and P2 Id expect, I see the hose to P2 has been replaced at some point, blank that off and the inlet to the slew and see if it still slews right but no left, then that proves a fault in the input side, then you can trace back up that line to what the fault may be. It looks like a one piece fitting and could well be over crimped

[v8druid]

or tee a pressure gauge into each line and see what you're getting .... agree with Muz on the P1/P2 lines.

That new pipe does look like it's had a bloody good squeezing Muz

[Muz]

or tee a pressure gauge into each line and see what you're getting .... agree with Muz on the P1/P2 lines.

That new pipe does look like it's had a bloody good squeezing Muz

Yeah I dont think its that though .. if as the op says, there no change in engine note on the faulty side, its not getting loaded, but at least he can identify the faulty line and trace it back. Either the oil is going back to tank somehow, or the service isnt being pulled on.

I did mention earlier, that Ive had a fair bit of trouble with pilots before, sticking, in fact Ive posted about it on here, still got to say I'd like to see that pulled and inspected first and foremost, it doesent take much for them to malfunction.

I take it no ones had the slew motor off and apart ? cos those are usually lobe pumps that drive the pinion and all the internal sections are 'timed' if someone hasnt reassembled it properly you get all sorts of problems although also less than likely if it was working.

Keeping things simple, I assume its not a fault caused by some interaction with the boom offset service ? what operates that ? is it a pedal on the floor ? cos the same lever controls it.

[nic9]

or tee a pressure gauge into each line and see what you're getting .... agree with Muz on the P1/P2 lines.

That new pipe does look like it's had a bloody good squeezing Muz

Looks like it's not lines P1 and P2. Swopped them over but still swung right (no left), this time on the left lever.