JCB 8015 arm not lifting

[craig]

With the plug removed, are you getting a supply, switched with the armrest up/down?

 

[Moog]

clean the coil off and see if there are any cracks in the casing and whether it has swollen at all.
how 'good' is the magnetic pull?
I have had coils where they're only providing a 'weak' pull, insufficient to operate the shuttle ... had one on the slew brake on the 'Drema - had me going for a while, 'til i swapped a known operating one and the brake came off - new one acquired and job sorted

The pull seemed quite strong, holding an Allen key firmly down. I will check for cracks etc later.
just going back to Monkeybusiness comment, what we have noticed is the dead man’s handle was not working yesterday, with a 12V supply even with the armrest up. However, when we tested it to start with, the switch opened and closed with the armrest up/down. I will check this out again as I think I’m going mad!

 

[V8Druid]

my 8015 will start with the dead man up or down - just for info.

The pull seemed quite strong, holding an Allen key firmly down. I will check for cracks etc later.
just going back to Monkeybusiness comment, what we have noticed is the dead man’s handle was not working yesterday, with a 12V supply even with the armrest up. However, when we tested it to start with, the switch opened and closed with the armrest up/down. I will check this out again as I think I’m going mad!

solenoid seems ok then

 

[Steve]

Check its energising correctly when plugged in and the armrests are up/down during ‘normal’ operation, not just with a known 12v supply. My guess is the issue isn’t the solenoid, it’s the wiring/switches feeding it.

My money is here too.

 

[Moog]

Am I allowed to say “oh bugger!” - not that I wanted the expense of a new solenoid, but still need to find the problem.
Cheers guys, Merry Christmas, will report back after more head scratching!

 

[diggerjones]

Am I allowed to say “oh bugger!” - not that I wanted the expense of a new solenoid, but still need to find the problem.
Cheers guys, Merry Christmas, will report back after more head scratching!

Aren't the guys implying it isn't the solenoid

 

[V8Druid]

Aren't the guys implying it isn't the solenoid

certainly looking that way Dylan, but TBH, with the amount of effort that's gone into it so far, I would be giving it a direct 12V supply and trying the hydraulics to ABSOLUTELY rule it out, before getting it all back in situ and whilst Moog still has access to that end of the wiring circuit to test continuity, IF the solenoid energises independently and over-rides the dead man circuit, providing hydraulics to the servos, etc.

 

[jd6820]

Hi,
Our 8015 has lost power to the cab hand controls and hence the arm will not lift. The week before we had attempted to tighten the fanbelt, which is in a very tight spot, so had removed the seat to access back of the engine. I wondered whether i had knocked something in the process to cause our problem.
We’ve checked fuses and the hydraulic oil level.

I’ve been testing the dead man’s handle on the arm control to see if the issue is linked. I’ve traced 2 yellow switch wires into the engine bay, found 2 connectors which both show continuity with the tester. The wires then go into braiding with other wires and I lose the trail. But I can see 2 yellow wires that are at the back of the engine, which I thought could be the same continuous wires, but when I do a continuity test from the last visible connector, 1 wire shows continuity with both terminals, and the other wire beeps and shows 0.4V on both terminals. So im not sure what is going on.

Be grateful if anyone can help with why the arm is not lifting, or tracing the switch wires.

cheers.

Did the excavator operate after the work was carried out?

 

[Moog]

Did the excavator operate after the work was carried out?

No

 

[Moog]

certainly looking that way Dylan, but TBH, with the amount of effort that's gone into it so far, I would be giving it a direct 12V supply and trying the hydraulics to ABSOLUTELY rule it out, before getting it all back in situ and whilst Moog still has access to that end of the wiring circuit to test continuity, IF the solenoid energises independently and over-rides the dead man circuit, providing hydraulics to the servos, etc.

We will try this tomorow, cheers

 

[Moog]

Hi guys
We’ve tested the dead man’s handle a few times again and it does seem to work properly with 14V showing while engine running, coming up to the solenoid coil. I blame operator error for the previous anomalies, I don’t think I had tester probes making good contact. Also connected the valve block direct to the battery with still no response from the controls. We also tested the coil separately again direct to 12V and I could put the coil up with the screwdriver magnetised.

So if the coil works ok, my next question is would the metal shaft going into valve block fail?

 

[Monkeybusiness]

Hi guys
We’ve tested the dead man’s handle a few times again and it does seem to work properly with 14V showing while engine running, coming up to the solenoid coil. I blame operator error for the previous anomalies, I don’t think I had tester probes making good contact. Also connected the valve block direct to the battery with still no response from the controls. We also tested the coil separately again direct to 12V and I could put the coil up with the screwdriver magnetised.

So if the coil works ok, my next question is would the metal shaft going into valve block fail?

They can get sticky - I have no experience of your exact setup but have had those poppet valves fail on woodchippers in the past.
You should be able to unbolt the valve and withdraw it from the body but will need a plug/bung to stop oil leakage whilst you have it out. You can then visually test that it works properly when energised/deenergised.
Someone on here sold the rubber butt-plug things that are perfect for jamming in the valve body whilst you have it apart (but I can’t remember who)?

 

[V8Druid]

They can get sticky - I have no experience of your exact setup but have had those poppet valves fail on woodchippers in the past.
You should be able to unbolt the valve and withdraw it from the body but will need a plug/bung to stop oil leakage whilst you have it out. You can then visually test that it works properly when energised/deenergised.
Someone on here sold the rubber butt-plug things that are perfect for jamming in the valve body whilst you have it apart (but I can’t remember who)?

cock on Dan - on all counts .... Gra was selling the plugs, 'til he got threatened with court action, by someone else flogging the exact same ones
quite poss. the shuttle is stuck in that valve .. will need a 16-20mm bung at least ...
sounds like it can't be much else, other than an internal issue in the valve block itself ??
this is roughly what it'll look like Moog - that's a normally closed - yours is likely to be a normally open

 

[V8Druid]

Hi guys
We’ve tested the dead man’s handle a few times again and it does seem to work properly with 14V showing while engine running, coming up to the solenoid coil. I blame operator error for the previous anomalies, I don’t think I had tester probes making good contact. Also connected the valve block direct to the battery with still no response from the controls. We also tested the coil separately again direct to 12V and I could put the coil up with the screwdriver magnetised.

So if the coil works ok, my next question is would the metal shaft going into valve block fail?

that ''metal shaft '' is a hollow tube Moog, with the shuttle inside it, sliding back and forth when the magnetic coil is energised, moving the valve inside the valve block.
as said, it is poss that the magnetic field is weak, too (not strong enough to move the shuttle) ... trying it with the cartridge removed may confirm its abilities, assuming the shuttle is free moving.
there is also the coils resistance moulded into the plastic body usually, you could check
can't think of a.n.other coil on there you could swap out for a check

 

[Moog]

that ''metal shaft '' is a hollow tube Moog, with the shuttle inside it, sliding back and forth when the magnetic coil is energised, moving the valve inside the valve block.
as said, it is poss that the magnetic field is weak, too (not strong enough to move the shuttle) ... trying it with the cartridge removed may confirm its abilities, assuming the shuttle is free moving.
there is also the coils resistance moulded into the plastic body usually, you could check
can't think of a.n.other coil on there you could swap out for a check

Great, thanks for that - will have to work on a suitable bung first so don’t have oil p**sing out everywhere, plus access is still a dog, I have to get my son to pull the block back as much as he can while I prise my fingers around the frame to get to the block - oh the joys of a mini digger!

 

[V8Druid]

Great, thanks for that - will have to work on a suitable bung first so don’t have oil p**sing out everywhere, plus access is still a dog, I have to get my son to pull the block back as much as he can while I prise my fingers around the frame to get to the block - oh the joys of a mini digger!

screw in plastic fitting bungs're as good as anything for preventing massive losses ... I doubt you're gonna lose massive amounts TBH - will be run back from the servo lines mostly, if anything .. the pump hoses feeding it're below it - the servo feed lines have the most height/head to cause loss from run back
I also find that cable gland shrouds also work very well ... they'll push/screw into a port very nicely

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Pardon our interruption...

 

[V8Druid]

just occurred to me that I have also had an issue with a DIN connector on a coil .... was showing voltage but not passing sufficient current to energise the coil properly (Also took some finding) .. freak one, but the stud into the connector had broken the spade (presumably in manufacture) and had given up the struggle to pass current
yours appears to be on flying leads/connector though, (but worth checking the connections)

 

[jd6820]

Provided it is magnetising the coil as you suggest it sounds like an actual oil issue. Do any of the non pilot controls still work? Blade and tracking? Sorry if this was mentioned in the original post and I have missed it. You have two ways to go from here one is using gauges and pressure testing the pilot circuit. The other is stripping the block down and seeing if anything is a miss. My concern is that it has only ceased to work since the repairs were carried out. Makes me think far less likely to be a mechanical fault with the block? There are check valves in the block that fall apart and can do weird things with the pilot oil flow. But functions usually still operate allbeit whilst using two functions at once or one dead ended...

What bits of the machine have you had apart exactly?

 

[jd6820]

Hi guys
We’ve tested the dead man’s handle a few times again and it does seem to work properly with 14V showing while engine running, coming up to the solenoid coil. I blame operator error for the previous anomalies, I don’t think I had tester probes making good contact. Also connected the valve block direct to the battery with still no response from the controls. We also tested the coil separately again direct to 12V and I could put the coil up with the screwdriver magnetised.

So if the coil works ok, my next question is would the metal shaft going into valve block fail?

The valve itself is unlikely to fail, could maybe jam with debris (broken parts of a seal/o-ring) but generally undisturbed they are usually not too bad. Being immersed in oil means they usually don't stick either, even if stood for periods of time.

 

[Moog]

Provided it is magnetising the coil as you suggest it sounds like an actual oil issue. Do any of the non pilot controls still work? Blade and tracking? Sorry if this was mentioned in the original post and I have missed it. You have two ways to go from here one is using gauges and pressure testing the pilot circuit. The other is stripping the block down and seeing if anything is a miss. My concern is that it has only ceased to work since the repairs were carried out. Makes me think far less likely to be a mechanical fault with the block? There are check valves in the block that fall apart and can do weird things with the pilot oil flow. But functions usually still operate allbeit whilst using two functions at once or one dead ended...

What bits of the machine have you had apart exactly?

The blade, tracking and slew all work Ok. I’ve not ventured into the valve block as yet.
initially we tried to tighten the fan belt by accessing from behind seat, but gave in and decided to move to a clean floor where we could access underneath. That is when we started her up and the hand controls lost power and the jib arm would not lift. Did test on dead man’s handle and followed power all the way to coil. Removed coil and tested separately. That is what we have done so far.