Bobcat 341 Excavator has no power under load

Dirk Lately · Jul 22, 2019

My beloved Bobcat 341 with 2400hrs started misbehaving yesterday. First it ran fine for probably 90 minutes, then, When applying load on ANY function, the engine began to bog down to the point it would die if I didn't relax the control. Everything still moves, but only very slowly, otherwise the engine will bog and die.

I'm not a mechanic and at this point just trying to troubleshoot. I'd really appreciate any help, especially steps to isolate the issue.

Thanks

SSdoxie · Jul 24, 2019

The 341 has a variable displacement load sense pump. When working correctly the pump senses flow at pressure and adjusts flow rate to match engine horsepower to prevent bogging as described. Testing/adjusting the pump is very detailed process that requires special hydraulic fittings, gauges, and adjustable load flow meter.
First step is identify or rule out a problem with the engine. Check air filter and intake system to make sure no air flow obstruction. Check fuel supply; clean uncontaminated fuel, clean filter, and working lift pump. Run engine to full throttle and move one of the hydraulic functions while watching the exhaust smoke.

1. Trace of black or gray smoke is normal at engine start
2. Engine warm at full RPM should see no smoke. If there is trace of black/gray smoke indicates engine problem; air supply, fuel supply, poor injection.
3. With hydraulic under load should see black/gray smoke as engine attempts to recover RPM. If no smoke at this point I would suspect injection pump governor not responding if all else has been eliminated.

If engine problem is ruled out then best bet is contact dealer. Either the torque limiter is stuck or is obstruction in load sense line.