I have changed oil and filter and sensor to get rid of the code I have a gauge on it too ... but I still have the error code.. i think I understand what the charge pressure being low effects finally normal demand for oil has no symptom ... I bought a trencher attachment and it has high demand for high pressure oil. If I try to run machine at 2000 rpm it will stall or nearly stall every 5 seconds like clock work running trencher with no load... if i back Rpm to 1600 it will run continuous with out problems. Charge pressure with no load are steady at 390# when it stalls it is dropping to 360# So back to charge pressure settings I tried to up the pressure by adding shim washers as the manual states ... but it is in such a b*****d place I can not install it with extra shims. It is too difficult... like the task is really meant for the bench. Does this sound familiar to anyone? Does anyone have any experience doing the shim thing? will it net results? Please help with some ideas.
If you have good oil supply, and your pump is not putting out, raising the relief is not gonna help. Your charge pump has probably been hurt. They are typically gear pumps(fixed displacement) They, by nature, degrade over time . I would remove and inspect, if possible.
I agree but it is not a relief setting.... it is the actual charge pressure setting, according to the manual adding shims increases the charge pressure... great have you tried that...oh my God you have to fight the spring to start the first thread ... well that spring is very difficult to compress ... it may be toast on getting the higher charge pressure ... i was just wondering anyone has experienced following the manual and had success?
it actually does make no sense the charge pressure setting would help its location in between the drive pumps ... the problem exists if i simply run the aux at too high of RPM .... and what happens is it put a big load on the motor ... is it a possible fuel flow issue? that only a heavy load reveals? ... I was trying to fix the code problem but it could be just another problem?
keep in mind when i do run at high RPM the trencher in the air mind you or in the ground... it will run fast and hard for 5 seconds then the engine coughs, drops RPM, drops pressure, and if i don't release the aux it will die.... so does that help?... the code may be unrelated? normal RPM of 1600 has no issues whether the high flow is in or out higher rpm of 2000 the problem shows up.... I will test other motor type attachments for the issue, I also got a brush hog and a tiller. maybe if i get all the symptoms accurate it will get me going in the right direction
OK, does the manual explain how adding shims increases the pressure? cause it sure sounds like a relief valve to me...
Increasing the charge pressure isn’t going to change anything. You already have good charge pressure and it’s not dropping much. It sounds as though you don’t have the flow at 2000 rpm to run that attachment at that speed.
Are you running flat face connections? I have had them not fully depress the inner plunger to where they begin choking off oil flow. Something to look at.
Yes It has done it on every hook up so far. I had just bought a used Trench and had pin issues which I though was dragging it down... well I fixed the Trencher ... and still have half the problem ... its a TR48 John deere trencher rated for 16-44 GPM (I have been told)... the manual states adding .0010 shims increase pressure 8# ... I do have a high flow brush hog to try it on after I fix a leak next week ... that will be interesting ... also i will change all the engine filters and oil next week, just because engine could be starved of fuel or air ... and yes engine does puff out some black and blue smoke when it is choking. thanks for the ideas!
Then I would look at the couplers on the machine itself. If possible I would hook the machine to the attachment without going through the coupler using a union or adapter hose or something to verify whether or not the couplers are at fault.
I just replace one of the couplers because it was difficult to take on and off. I could probably rig a simple loop between couplers for a limited check. but first I want to make sure engine can handle the load. And i want to check my brush hog and tiller to see if I have just ignored the problem on them. Like I stated everything is fine at 1600.. its when I push the envelop doing higher RPMs that the issue exists. If the machine was made to run all out at 2400 rpm then i want it.
correct me if im wrong... if the gear pump has low output = less load on engine
fuel pump was bad... not it does not stall/choke under a load ... that should do it, after all it stalled with no load, I just thought the charge pressure low error code had something to do with it .. best i can tell is low charge pressure will lower my lifting weight limit, a function that more pressure gives better results.... I will check the trencher again soon .... thanks for your comments!