Cat D5C dozer left side won’t move

[RDBFARMS]

We had to replace the ignition switch on our dozer and now the left side track won’t move. It feels like the brake is on. Is there an electrical component that turns the brake on or off?

 

[Nige]

Can you start with a Serial Number please. there are a dozen different models of D5C.
Is your tractor hydrostatic drive, because if it is then Diagnostic Codes are going to be the next step.

 

[RDBFARMS]

I’m not near the machine but I can tell you it’s late 90s model D5C Series 3 Hystat drive.

 

[RDBFARMS]

And it’s also an LGP

 

[Nige]

I’m not near the machine but I can tell you it’s late 90s model D5C Series 3 Hystat drive.

A Serial Number when you can please.

Meantime get into the Diagnostic Indicator and see what Blink Codes it comes up with.?
The Harness Code connector referred in the procedure is the 8-pin one in the upper LH corner of the photo.

 

[RDBFARMS]

I got the serial number today. It’s 6CS00829. I think the machine may be older because I am unable to find any diagnostics likeyou suggest.

 

[Nige]

I can tell you it’s late 90s model D5C Series 3 Hystat drive. I got the serial number today. It’s 6CS00829. I think the machine may be older because I am unable to find any diagnostics like you suggest.

It actually dates from June 2000 but it doesn't have the all-singing all-dancing electronic system on it that I originally thought and posted above.

You're going to need a fair bit in the way of test equipment unfortunately. See the attachment.

FYI the pressure gauges you need are 400kPa - 60psi, 1000kPa - 150psi, 4000kPa - 600psi.
You will be able to get by with one of each, just that the testing will take longer because you will have to stop more frequently and keep swapping gauges between test points.

Before you go further, when was the last time the filters were changed in the hystat.? it may pay you to pull the filter and cut it open to look for sparklies and/or shrapnel.

 

[RDBFARMS]

We had a mechanic out today unfortunately I wasn’t there but I know he did not perform all of these test procedures. He disassembled the final drive and that looked fine. His diagnosis is bad hystat drive pump on the left side. Quoting $18k to repair. Thanks for sending the attachment. I think we’ll have him put it back together and we perform the tests ourselves. Thanks again.

 

[RDBFARMS]

first we’ll change the filters, I’m not sure of the date they were changed, but we only put 200hrs/yr on the machine.

 

[Nige]

first we’ll change the filters

I think that is a good plan. When you remove the old filter(s) use this VIDEO as a guide on how to cut open the old filter and inspect the media for metallic/non-metallic debris.

2 things - a) Yes I know it's an engine oil filter in the video but the general principle is the same for all filters and b) you don't need a fancy filter cutter. You can make do nicely with a set of tin shears or a hacksaw provided you're careful.

Be sure to post photos of anything interesting you find in any of the filters.