Cat 330BL - Won’t rev up to take load

[Pralhad Birdi]

Hi all,
I’ve just bought a Cat 330BL 6DR00608 excavator. It’s a generally clean machine, engine sounds good, 8000 hours on the clock.
Hydraulics seem okay, the machine is able to lift itself off the ground at idle speed, and tracks independently without bogging down.
The wiring seems to have been messed about with a fair bit though, and as a result, when you set the engine speed to auto on the monitor (the button on the right), the engine will initially rev up, but then immediately rev back down and refuse to compensate for load.
When you set the engine speed to manual, it revs up fine, but will not rev down when not under load.
The accelerator unit seems to have been changed fairly recently, so not sure whether this would be a calibration issue. Also, the engine will not switch off from the ignition, nor will it switch off from the manual override on the back of the shut off solenoid. I have to load it to get it to switch off.
On the left hand joystick, where the fuse box is, loads of wires seem to have been connected up fairly badly, and I’d assume (though I’m not sure) that there should be the auto/manual flip switch there, as well as the rev auto/manual as on the 320C. These are both missing, and wires have been joined up with in line fuse holders.
Could anyone point me in the right direction with how it’s supposed to be, and what I’d need to do to get it back to factory spec?

Thanks

 

[Pralhad Birdi]

Bit of an update:
Located the auto/manual switch behind the right hand operator joystick console.
So when I put it on manual, I’m able to control engine speed with the flip switch next to it and with the dial as well.
When it’s on auto, and the monitor display is on n/auto, then the engine revs up and back down, and then doesn’t rev up again.

 

[Nige]

Check your message inbox for an electrical schematic plus other info.

 

[Pralhad Birdi]

Just a bit of an update on this machine:

So we changed a lot of the hydraulic pipes, most of the pilot pipes from the joysticks, new tanks on the radiator, oil and fuel service and cleaned up the wiring.

The controller wasn’t mounted on its plate as the bolts seemed to have rusted through, so made a raised mounting for that and bolted it down.

Changed the shut off solenoid on the injector pump, and now engine switches off from the ignition.

Activated Service Mode and cleared logged errors. No new errors came up after that, and action lamp is off.

Removed the flywheel speed sensor, and it seemed to have been screwed in too far, as the plastic bit on the tip was scored. Still waiting on a new one, but correctly adjusted that and reconnected.

Tested the machine, and the AEC seems to be working fine when the hydraulic oil gets up to temperature. When cold, still a bit intermittent.

New issue:
Operated the machine for about 15 minutes or so, and it was perfectly fine.
Then Monitor Alert and Controller Alert indicators came on, and lost everything on the monitor apart from the two alerts and the time.

Tracked the machine back to parking bay, and the AEC and the engine speed dial are still working fine.

I’ve tried activating Service Mode again, but it won’t let me. Just beeps when I press the buttons, but nothing.

When I switch the ignition off, and on again, the monitor lights up as normal, but then everything disappears and the two alert indicators remain.

Currently removing the seat and side panels leading up to the monitor to check for any loose connections etc. Checked all fuses, all are fine.

Any ideas what would be causing this, and what I can do to sort it out?

Thanks

 

[Pralhad Birdi]

Switched off the cut off switch, unplugged and re plugged the controller sockets, and checked all the fuses again.

Switched it on, and monitor came on and action lamp was on. Managed to activate Service Mode, and it had logged two errors:
- 4103 - PRV circuit is open
- 4204 - PWM sensor of pump delivery pressure is shorted to ground

Checked the harness leading up to the PRV (I’m assuming it’s the one next to the accumulator on the pilot block) and visually all wires seem fine.
Unplugged the pump delivery pressure sensor and checked continuity at the wires - continuity only exists on the ground wire, so I’m thinking no shorts there.
Opened up the panel behind the cabin that houses the main relays etc - found a thin (1/1.2mm) wire connected to the lug of the main cable (the thickest one) leading from the relay to the controller and just hanging open ended. I dunno, but I suspect that this might have earthed itself while the machine was moving around, possibly causing the issue?
At any rate, pulling all the panels in the cab behind the seat etc to clean up connectors and check for any possible shorts or breakages.

Anything else I can check?

 

[anuradha]

the engine will initially rev up, but then immediately rev back down and refuse to compensate for load.

Hi,

In auto deceleration mode If there is no hydraulic demand from the machine it will detect by the Ecm via implement pressure switch and After about 03 seconds ecm will put the engine rpm down until it detects hydraulic demand again via implement pressure switch. When control levers are operated due to pilot oil pressure implement pressure switch is closed sending signal to the ecm and then ecm sends the signal to governor motor to accelerate engine speed to current engine speed dial's speed setting.

If the implement pressure switch is faulty or wiring is faulty, after deceleration again auto acceleration doesn't happen with hydraulic load applying. So check wheather impement pressure swith works correctly.

 

[Pralhad Birdi]

Whereabouts is the implement pressure switch, and how can I test it?

It is worth mentioning that this issue is most prevalent when the machine is cold - once it warms up slightly, it gets better

 

[Pralhad Birdi]

Hi,

In auto deceleration mode If there is no hydraulic demand from the machine it will detect by the Ecm via implement pressure switch and After about 03 seconds ecm will put the engine rpm down until it detects hydraulic demand again via implement pressure switch. When control levers are operated due to pilot oil pressure implement pressure switch is closed sending signal to the ecm and then ecm sends the signal to governor motor to accelerate engine speed to current engine speed dial's speed setting.

If the implement pressure switch is faulty or wiring is faulty, after deceleration again auto acceleration doesn't happen with hydraulic load applying. So check wheather impement pressure swith works correctly.

Also, do you think this could cause the errors I saw? And would it cause the monitor/controller issue?

Thanks

 

[Nige]

It is worth mentioning that this issue is most prevalent when the machine is cold - once it warms up slightly, it gets better

If the symptoms get better when the machine warms up what viscosity of hydraulic oil are you using.?

 

[Pralhad Birdi]

If the symptoms get better when the machine warms up what viscosity of hydraulic oil are you using.?

To be honest, I’m not sure as it’s got the oil it had in it when I bought it.
The previous owners don’t seem to know either.
What viscosity do you reckon would be suitable? I can drain and refill with that.

 

[Nige]

SAE10W or ISO AW32 hydraulic would be recommended for your climate.

 

[Pralhad Birdi]

SAE10W or ISO AW32 hydraulic would be recommended for your climate.

We normally use AW32 for all our machines. Will drain and refill with that.
Thanks

 

[heymccall]

I'm a little rusty on B machines, but for monitor issues, the non sealed plug behind the trim by your right foot (when in the seat) has been an issue on some. I know that's an issue on "C" machines, just not sure on a "B".

As for the AEC, I think you can monitor the implement pressure switch status via the correct mode in the monitor, along with the other pressure switches. Again, I know you can on "C" machines.

 

[Pralhad Birdi]

I'm a little rusty on B machines, but for monitor issues, the non sealed plug behind the trim by your right foot (when in the seat) has been an issue on some. I know that's an issue on "C" machines, just not sure on a "B".

As for the AEC, I think you can monitor the implement pressure switch status via the correct mode in the monitor, along with the other pressure switches. Again, I know you can on "C" machines.

Cheers mate, will have a look at that

 

[Pralhad Birdi]

SAE10W or ISO AW32 hydraulic would be recommended for your climate.

So confirmed with the previous owners, said they’d put 32 in there.
So I’ve sent the machine off to site, and it’s done its first full day’s work.
Had the AEC off, so operator was controlling RPM.
First 4 hours or so machine worked well, then hydraulic oil temperature started rising, and it started losing power.
So that’s been the case for the rest of the day as well - high hydraulic oil temps and not a lot of power.

Oil cooler fins were pressure washed through before sending it to site, and water temperature is good.

Fan is sucking in, which is also the case on my 320. Thought it might do better with blowing out like on the D6H, but fan seems oriented correctly, and turning it around won’t make a difference to direction of air flow as far as I can tell (maybe just make it less efficient)

The climate is fairly hot where we’re working - mid to high 30s Celsius - but I’ve got three other excavators and a dozer on site and no similar issues.

Any ideas what could be causing the rise in temperature and subsequent loss of power?

I had a similar case on a 317B a little while ago, and it turned out that the pilot pump was gone on that. Can’t tell if this had a standalone pilot pump - couldn’t see one

 

[Nige]

fan seems oriented correctly, and turning it around won’t make a difference to direction of air flow as far as I can tell (maybe just make it less efficient)

That is correct, but are you SURE that it is oriented correctly right now.?

TBH the only way to completely clean the various elements of the cooling pack is to tear the whole thing apart and clean each element individually. You will be amazed how much crud gets trapped in there that you can't see from outside.

Can’t tell if this had a standalone pilot pump - couldn’t see one

The pilot pump is a gear pump that is attached to the end of the lower main implement pump.

 

[Pralhad Birdi]

That is correct, but are you SURE that it is oriented correctly right now.?

TBH the only way to completely clean the various elements of the cooling pack is to tear the whole thing apart and clean each element individually. You will be amazed how much crud gets trapped in there that you can't see from outside.


The pilot pump is a gear pump that is attached to the end of the lower main implement pump.

I will ask for a photo to be sent from site tomorrow morning to confirm fan orientation.

I suppose it would be a good shout to remove the oil cooler and clean from inside then. Any relief valves or similar on the lines that might get trapped open/shut that I need to check?

 

[Pralhad Birdi]

That is correct, but are you SURE that it is oriented correctly right now.?

TBH the only way to completely clean the various elements of the cooling pack is to tear the whole thing apart and clean each element individually. You will be amazed how much crud gets trapped in there that you can't see from outside.


The pilot pump is a gear pump that is attached to the end of the lower main implement pump.

Checked the fan orientation, and it’s oriented correctly.

Currently taking out oil cooler to properly wash both inside and out.

We’ve taken off the valve that sits on the side of the main spool valve body (connected to case drain pipe). Seems to be actuating as it should.

We’ve also taken out the valve further along on the return pipe to the big filter, also wasn’t stuck or loose.

Taken out the filter housing - it has a valve at the bottom that’s actuated by a solenoid - this doesn’t seem stuck either.

However, what does the solenoid/valve do? Would it make sense to unplug the solenoid and see if that makes any difference while running?

Machine runs perfect when cold, but after a few hours, hydraulic temp climbs to 8bars on the dial and we lose power

 

[Pralhad Birdi]

 

[Pralhad Birdi]

Just a bit of an update - things continue to get progressively better with this machine

We cleaned out the oil cooler and all the associated bits on the tank return line.
Put everything back together, and now it wont lift the boom.

All the other functions are okay, just has no power in the boom.
It comes down like a tonne of bricks, but struggles to go up.

I’m not near the machine, and won’t be able to get there for a couple of days, but have been trying to diagnose it over video call (great fun)

Got my guys to unplug the wire that goes to the top of the spool nearest the cabin, and it briefly lifted the boom as it should.
Put it down, and went back to no power.

Tried changing modes on the monitor etc, putting it into manual back up mode, no difference.

I’d really appreciate any advice on what this could be caused by.

One thing worth mentioning - we are piped for breaker, but there’s no pedal in the cab. We’d taken the breaker lines off when we bought the machine, just to clean up the welding on the clamps holding it to the stick. So we’d drained the line.
Now we’re seeing a leakage on the breaker line. Why should it be pressurising if we’re not using it, and don’t even have a pedal in?