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Cat 215 weak hdyraulics

Dgreen4298

Well-Known Member
Joined
Dec 3, 2015
Messages
156
Location
Northern indiana
A46F3025-6E03-4D93-BC74-B1A2BFCAA443.jpeg I am talking about just the governor part of the injection pump, it is basically the back section of it. I have checked high rpm with a reliable laser rpm meter and get consistent 2120 high rpm and 720 low rpm at crank pulley, manual calls for 2080 no load and 2005 during operation of boom and stick. I called a fuel shop and they will only do a complete overhaul for the entire pump for around $2000 even if I have just a broken spring or something, so obviously I am not taking it there.
I feel like the engine is not adjusting rpm when a load is put on the hydraulic system, if it is supposed to, it will just die slowly.
I have been going through the procedures for checking and adjusting the hydraulic system first, what else would I check on the fuel system if all the lines are new, new filters, transfer pump is rebuilt and delivers plenty of pressure to the injection pump? Turbo seems fine but I don’t really know how to check it. There is no play or slop in it.
 

Nige

Senior Member
Joined
Jun 22, 2011
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28,973
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G..G..G..Granville.........!! Fetch your cloth.
TBH I think you are shooting from the hip regarding probable root cause. There appears nothing particularly to suggest that the engine is the issue yet you persist with chasing remote possibilities of engine problems, when in all truth the most likely thing is the hydraulic pump control side. See the paragraph below from the System Operation document for the implement hydraulic system.

The excavator system is designed to operate with the governor control setting on maximum engine speed (rpm). If both axial piston pumps are working at full output and maximum pressure at the same time, the horsepower needed would be approximately 2.3 times as much as is available from the engine. To prevent an engine stall, a control system has been installed that can tell when there is a change in pressure in one of the implement circuits. When this condition happens, a signal from the control system is sent to the axial piston pumps that causes them to decrease their output. In this way, the control system makes sure that the power needed to operate the hydraulics is always available from the engine.

I would strongly suggest that you try to understand how the pump control system works before going any further.
 

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  • 215 Hydraulic SysOp.pdf
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Dgreen4298

Well-Known Member
Joined
Dec 3, 2015
Messages
156
Location
Northern indiana
Are you suggesting that I have a summing valve adjustment or failure issue? I am going through the control system testing procedure now. Do I need to use a volt meter on the brass terminal on the governor because I cannot find it. There is a picture in the procedure but it is not very good, basically just shows the fip.
 

Dgreen4298

Well-Known Member
Joined
Dec 3, 2015
Messages
156
Location
Northern indiana
Also I need to know where the pump selector valve is. I think this might be where it goes but it looks like this machine does not have one. If this is the case is it possible that governor does not have the necessary brass terminal either for preforming this procedure. The procedure I have is from sis and is for my serial.
 
Last edited:

Dgreen4298

Well-Known Member
Joined
Dec 3, 2015
Messages
156
Location
Northern indiana
Ok I have found the brass terminal on the rear of the governor, however when I connect a meter to it and frame ground and move the governor lever the numbers to not change. Manual says it should go to 12 volt when throttle is fully open, mine only had about 6v and didn't change with throttle position but the voltage did slowly drop when engine was shutdown and the engine temp dropped. It says that if this happens I need to remove the cover and push pin down manually. My question is, what cover? I assume it is the cover that the governor arm goes through but I really don't want to take it off and have a bunch if stuff fall out.
I am trying to go through the pump controls testing procedure and this is needed for that.
 

J.R. Britt

New Member
Joined
Sep 29, 2018
Messages
4
Location
Hampstead N.C.
I know this is old but I have a E120B Cat that does the same but with black smoke, If anyone can tell me something I would appreciate it.
 
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