Recently purchased a 1995 335L to use in my pit digging and loading select fill and sand. Its got 3 cylinders leaking pretty good and needs new bucket pins and bushings. When testing, it appeared to have hydraulic power as it would pick itself up and went thru all the motions easily. When I got it to my pit, I tried digging and about 3ft down hit some hard clay, the engine would bog and come close to dieing. Upon reading and internet research, I changed fuel filters and all hydraulic filters. It was 15 gallons low on hyd fluid, so we got that topped off as well. The fuel/water separator had some gunk in it as well as the main fuel filter. The one on the side of the engine with the pump on top did not have a filter in it so I cleaned it all up and installed a new filter, spring and retainer. Went and tried it out and it does the same thing. I think next step would be to check fuel pressure so I will see about rounding up a guage tomorrow. Would a relief valve sticking cause the engine to bog under heavy load? Any other ideas to check? TIA
SN 2SL00786
I would be checking fuel lines for screens or inline filters.
Just want to say that just because you just changed the fuel filter does not mean that another gulp of junk did not plug it again. Its what happened to a county machine here and took them 2 days to figure out that it was plugged again. Have you tried with fuel cap off. Have you disconnected fuel line at first filter to see how much fuel flows from tank. Could give it a blow back incase of blockage. Disconnect return fuel and put into pail to see if that line could be blocked off. Simon C
How hot is the hydraulic oil when the engine starts bogging down? The reason I ask I was operating a new 320 of about the same era that did a very similar thing but the hydraulic temperature climbed exponentially. It had a faulty valve in the control bank.