Caterpillar 257b3 Turning Issue

[Ruben1205]

Just bought this used 2012 Cat 257b3 with 4500 hours and it seems to have an issue with turning. It will sometimes turn good and then suddenly either not turn or turn very slowly. Runs forward and backwards just fine. Any ideas?

 

[Ruben1205]

Bucket and moving machine is no longer working now either. Fires up fine but hydraulics not working.

 

[Jenson48]

Serial number please

 

[Ruben1205]

*CAT0257BPB7H01275*

 

[Jenson48]

Checked fluid levels at all?

 

[Ruben1205]

Fluid levels are good. Just below max line on gauge

 

[Nige]

Do you have any warning lights on the panel.?

 

[Ruben1205]

Negative. No warning lights

 

[Nige]

Open the rear engine cover and fire up the engine. Does the radiator cooling fan start spinning immediately.?

 

[Ruben1205]

The fan does not turn on when fired up

 

[Nige]

In that case it is almost certain that the coupling between the engine and the hydraulic pumps has failed.

 

[Ruben1205]

Do you happen to know specifically where the coupling is located? Thanks for the help

 

[Nige]

Between the engine flywheel and the hydraulic pump. There appear to be two schools of thought regarding replacing it. One is to remove the engine and pumps as a unit and split them on the ground (this is the way the manual shows), the other is to pull the pump in the machine and replace it that way.

I’ll leave it to others to comment which method they prefer.

 

[Ruben1205]

Is there a way to check before removing?

 

[Nige]

Unfortunately not.

 

[Jenson48]

Unfortunately not.

What would cause it to only halfway work as far as turning but forward and backwards fine then drop off? Just the coupling barely hanging on until failure?

 

[Nige]

What would cause it to only halfway work as far as turning but forward and backwards fine then drop off? Just the coupling barely hanging on until failure?

Likely. If the fan isn’t turning then the likelihood is that the pump isn’t turning either.

 

[Jenson48]

What is the fan driven by?

 

[Ruben1205]

just a little more info:
- there was already a small leak from somewhere underneath. Not sure where it was coming from. Could it be that air got into the hydraulic system and stopped working?

 

[Nige]

What is the fan driven by?

One of the hydraulic pumps.

just a little more info:
- there was already a small leak from somewhere underneath. Not sure where it was coming from. Could it be that air got into the hydraulic system and stopped working?

Possible but I wouldn’t have thought it likely.