I bought an ‘18 E85. 2100hrs. Clean, tight machine. Didn’t go look at it so maybe my bad. Operates great for first 30 mins. but then there’s a noticeable slow down and weakness the hydraulics. Hard to get a bucket full of material and boom up is very slow. I don’t have a manual so I don’t know where to hook on to check pressure. Also been reading up some common issues and relief valve problems are mentioned regularly. My question is boom operations slow down, blade won’t hardly raise machine but it’ll push material rolling over the blade and not blink an eye. Where should I start? I did put new filters on but don’t know what oil is in it.
A damaged hydraulic pump coupling results in the entire excavator being unable to move or moving weakly: A damaged coupling between the engine and the hydraulic pump will prevent the hydraulic pump from outputting power, causing all excavator movements to cease. Because the coupling is broken or damaged, engine power cannot be transmitted to the hydraulic pump, the hydraulic system cannot function, and various actuators (such as hydraulic cylinders and hydraulic motors) will not receive power. Please check the following:
If it operates fine for the first 30 minutes, then it’s unlikely to be the coupling. I would be more interested in what the pump’s pressures are at. Do yourself a favor and buy the manuals, I need paper, not files. Then read the sections on checking pump output pressures. Drive pressures will be a different pump than digging pressures, or may be, not that familiar with the newer 85’s. Probably should post a serial number also. Take the time to check each function, when you say won’t pick up a full bucket, will it lift the tracks? Will it track both sides, forward and reverse? Hows the swing? We need a bit more information. When you changed the filter, is it still available, to check for metal? Do you feel it’s definitely the hydraulics and not the engine? Pictures help also. Edit to add, the internet is great for information but has probably caused more work to be done, from anxiety or looking for issues, then maybe saved from work.
B48411339 serial #. Engine seems to run fine, no noticeable difference in start up and after it’s been working awhile. Both tracks seem equal both directions.When I changed filters I poured oil in filters out and ran magnet through it and didn’t see any signs of metal. The port I hooked on to read around 3000 when it was cold. After running it till I noticed the slow down it dropped to 24-2500 on all operations except dipper arm and it ran up to 3900. All numbers were with it deadheaded in each function. I’m looking for a manual to print off tomorrow
Magnet, isn’t a bad idea but a lot of what’s involved, isn’t magnetic. Thats why cutting the filter open and squeezing the pleats in a vice and unfolding the accordion in sunlight, works best. Pressures don’t sound bad, are these P1 and P2?
Don’t know if this is the correct spot or not, but this is where I hooked up to.
main relief valve seals , remove cove left hand side low of cab to rear two on top and the rest low down, get part from bobcat not standing oring
Pump was worn but was salvageable so it was rebuilt. Just got it on. New Bobcat filters and oil. Works great but single function operation of boom up is still slow but if you activate a 2nd function it comes to life. What’s that about
That sounds like a valve issue.
Maybe the one in this picture?
I'd start by checking hydraulic pressure once the machine gets hot since the problem shows up after 30 minutes. If the blade will push hard but won't lift the machine, that points more toward a flow or pressure issue than an engine power issue. Make sure the hydraulic oil level is correct and that the oil isn't the wrong viscosity. Also check the hydraulic tank breather, suction screen, and whether the machine has a clogged cooler causing the oil to overheat. A relief valve sticking open when hot is definitely possible, but I'd verify pressures before throwing parts at it. The fact that it works well cold and fades as it warms up is a big clue.
Where is the main relief valve located on this machine? Found Aluminum block bolted onto main control valve but don’t think that’s it. Is it under the cab maybe?
No idea, never had an E85. Might want to think about getting the manuals on it.