MrKomatsu
Senior Member
I do believe that it may very well be the self pressure reducing valve and not the pilot pump.....i have had many dealings with that little valve...9 out of 10 times it has bn the screen cloged up....just my 2 cents......:usa
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Komatsu PC200-7LC Slow When Cold
- Thread starter nickbowers
- Start date
Dr Komatsu
Well-Known Member
The Dash 7 doesn't have a pilot pump .The SRPV takes a feed from one of the main pumps thru a drilling in the merge divider valve on the rear of the main control valve then regulates PP pressure down to PPC pressure . Have experienced low unload pressure from the main pump supplying the SRPV creating insufficent PPC pressure. Usually only shows up if guages are fitted directly into the pump test points and not using the monitor panel readings. I've only had problems with the SRPV on Pc350/450 size m/c but they are pretty much the same except for the mounting bolt holes on the SRPV itself.
MrKomatsu
Senior Member
I have a new problem.......Ihave seen many different problems but i'm stumped here...Pc200lc-7L.....first start up every thing is fine...all functions..normal...10 min. later no controls.....what a few min.....they come back ..over and over ......self pressure reducing valve was removed and no problem.....no codes.....all electrical..ok..
John C.
Senior Member
I ran across something like that on some Dash 6 machines a few years ago. What we did finally was pull the LS valves apart on the pump and then blow out the load sensing lines and the machine started working again. This is a little different than yours though since it was only one pump giving the problem.
The only thing I could suggest is plugging a gauge into the pilot circuit and seeing if the pressure goes away when the problem happens. I haven't worked on a Dash 7 so I would also wonder if there is an electrically operated pilot cutout instead of the shutoff valve under the cab. Could there also be a pressure switch somewhere? I've seen several of those switches leak oil into the electrical part and then become intermittent.
Good Luck!
The only thing I could suggest is plugging a gauge into the pilot circuit and seeing if the pressure goes away when the problem happens. I haven't worked on a Dash 7 so I would also wonder if there is an electrically operated pilot cutout instead of the shutoff valve under the cab. Could there also be a pressure switch somewhere? I've seen several of those switches leak oil into the electrical part and then become intermittent.
Good Luck!
posthoorn
Active Member
The quickest and cheapest way is to check if you have the correct oil for your hydraulick system and your area.
check also if suction filter for hydraulic pump is clean.
check also if suction filter for hydraulic pump is clean.
posthoorn
Active Member
i know the reply is late but anyway,
you can check unload pressure at high idle and levers neutral if pressure is lower then 30 bars you have to adjust unload pressure.
best regards
d_sully
New Member
Hey guys,
New to forum and hate to hijack a thread but unfortunately I can't post a new thread straight away. I have a problem with a Komatsu 300-6. The driver reports that after 2 or 3 hours the engine starts to die to nothing when he puts pressure on the hydraulics. Will close the bucket empty but once he tries to dig it starts to die. Has problems tracking aswell. Once he lets go of the levers she rev's back up again. It's an intermittent problem as every time I get to the machine she will not do it for me!! She starts for me no problem and I work her at high load but still nothing. Seems to be after a few hours the problem comes into it.
Fuel lines were changed lately along with filters. A new lift pump was fitted quite recently as well. Any pointers would be much appreciated. Injector pump has been disconnected from electronic control due to earlier problem I'm not familiar with. A hand throttle has been fitted.
New to forum and hate to hijack a thread but unfortunately I can't post a new thread straight away. I have a problem with a Komatsu 300-6. The driver reports that after 2 or 3 hours the engine starts to die to nothing when he puts pressure on the hydraulics. Will close the bucket empty but once he tries to dig it starts to die. Has problems tracking aswell. Once he lets go of the levers she rev's back up again. It's an intermittent problem as every time I get to the machine she will not do it for me!! She starts for me no problem and I work her at high load but still nothing. Seems to be after a few hours the problem comes into it.
Fuel lines were changed lately along with filters. A new lift pump was fitted quite recently as well. Any pointers would be much appreciated. Injector pump has been disconnected from electronic control due to earlier problem I'm not familiar with. A hand throttle has been fitted.