Hi Guys, Malcolm from Down Under Australia here. We have a Komatsu PC300-7 ( year : 2002 ) 180kW (240 Horse Power) excavator out in the bush. It works fine except : when raising the boom quickly and using another function at the same time it makes the hydraulics labor ( go to high pressure - say about 5300psi) & almost stalls the engine. Dropping the boom does not do this when combined with any other function. Any other combination of one or more functions from the main valve works just fine on the machine without an issue. We have already checked the engine and fuel filter and air engine air filter. Any ideas out there of what it might be? Thanks guys.
Good day Malcolm No power much required lowering the boom, most probable an engine problem. Had any water or dirty fuel recentl;y? Kind regards Uffex
There's what's called a merge divide solenoid. It basically gives you 2 pump flow in some operations vs 1 pump in others. For example swing and bucket don't require the flow of boom- up, travel and arm-in. Are both pump pressures rising to 5300? I'm also thinking maybe, the second boom spool might be sticking giving you a deadheading pump. Just food for thought. Are you measuring pump pressure off the display or physical gauges? I'm sure our friend Lachau will be along shortly. Tremendous resource on these older Komatsu
Thanks Guys, Just heard back from the man working on the machine. The problem was the engine. The engine revs were not set high enough and so there was not enough power to run the system. Engine revs were running low at 1900 rpm - this has now been increased and fixed the problem. Thank you for all your input guys - we really are on our own in Outback Australia as our hydraulic market is very small compared to the USA and any help is really appreciated. Cheers !
Thanks Guys, Just heard back from the man working on the machine. The problem was the engine. The engine revs were not set high enough and so there was not enough power to run the system. Engine revs were running low at 1900 rpm - this has now been increased and fixed the problem. Thank you for all your input guys - we really are on our own in Outback Australia as our hydraulic market is very small compared to the USA and any help is really appreciated. Cheers !