A costumer brought me a 297C s/n GCP00533 7660hrs. When you lower the boom or curl or uncurl the bucket it will bog way done. If it is at idle it will almost die. Costumer was told by a CAT man that it needs a new hydraulic pump. He wants me to just replace it. I'm not sure that that will fix it. Anyone have any ideas?
I wonder what the Cat man's reasoning was behind that statement.? You could tell the customer that if you replace the pump per his instructions and it does not fix the problem it's on him. IMO a bit of diagnosis is needed before condemning the pump. The implement system is electronic over hydraulic, not a pilot system. So why if the implements work fine when the boom is raised or the bucket is dumped (same implement pump) does the problem not occur as well.? You'd think there would be more hydraulic demand when lifting than lowering the boom. Do you have ET to enable you to look at the electronic side and eliminate that as a potential source of the problem.? If not you can access basic parameters via the upper RH dash panel in the cab. If you need anything such as a hydraulic schematic or test & adjust documents shout out.
With 7660 HRS on that unit there would be some wiring starting to show its age is my guess, Just look at a the D SkidSteers with wiring problems with less than 3000 hours. Never know what you wil find.. Simon C
I'm wondering if the pump is not destroking like it should. Like it goes to full output when it doesn't need to and then won't go back to neutral when it should. Any ideas on how to check that? Is it controlled by pilot pressure from the control valve or is it all internal to the pump? It does have high flow. I think that it uses the same pump for that as the it does for the arms and bucket.
Attached the Systems Operation document for the hydraulic system of a High Flow machine.
I'm thinking that there is something wrong in the Pressure and Flow Compensator Valve or in servo piston on the pump. I think the pump is not destroking like it should. Nige do you have the High Flow Hydraulic System-Test and Adjust document? I want to run some test and see if I can confirm that is what is happening.
The attached is specifically for the implement system. If you want anything else let me know.