980h boom issues

[grumpy mechanic]

Good day, this will be my first post and would like to thank everyone in advance for their past and present help.

I have a Cat 980h JMS04131with 21000 hrs. The machine has had a recent rebuild but is having issues with the boom functions. Currently the float is not working, the boom raise and lower detent magnets at times feel "weak" and very rarely the boom lift will stop when raising and will not move up or down unless you cycle the bucket tilt. I have replaced the raise and tilt control levers and bearings as they were worn, sticking and not centering - causing the bucket to raise by itself.

I should mention I have performed all the boom lever and valve calibrations in ET and the issue is still present.

I did find a code 351 with 6 occurrences, but no active codes at the time when I went to check it out.

If anyone has had this issue please feel free to reply, as the machine is currently at the shop for maintenance.

 

[Nige]

Sorry I missed this first time round.

Did the control issues start at the same time as the machine was reassembled after the component overhaul.?

I should mention I have performed all the boom lever and valve calibrations in ET and the issue is still present.

So you have calibrated the lift/tilt angle sensors on the implement linkage and the electro-hydraulics on the main control valve.?
But did you calibrate the position sensors undeneath the lift & tilt control levers in the cab.?

Would you like to try downloading an ET Product Status Report for the machine and either post it up or send it to me on a PM, whichever you are most comfortable with.

 

[grumpy mechanic]

Nige, as far as I know the issue arrived well after the rebuild.

I'm not near my laptop right now but I believe the first calibration (1 of 3 I preformed in ET) is the lift and tilt lever sensors, then the angle sensors, followed by the electohydraulic valves on the mcv.

The code I had was 351-4. I noticed the tilt angle harness was taped up and I ordered a new tilt angle sensor. I also order a new float check valve (float circuit in the pilot valve), just in case. The machine is now a couple of hours away, so I figured I should come prepared.

I'm pretty new to Caterpillar machines, so thanks for your patience!

 

[Nige]

I'm not near my laptop right now but I believe the first calibration (1 of 3 I preformed in ET) is the lift and tilt lever sensors, then the angle sensors, followed by the electohydraulic valves on the mcv.

If that is the case then you got all three calibrations. Your first post wasn't 100% clear.

Regarding your 351-4 Diagnostic Code see the attached troubleshooting procedure containing a truncated electrical schematic. If you would like a complete schematic please ask.

When you go back to the machine I suggest the first thing you do after connecting ET is to download a Product Status Report. Click this LINK for a tutorial on how to do it. Really the only thing you need to remember is to click the "Select All" button on the lower left side, then click "Create Report".