JD 350 loader - boom & bucket hydraulics quit unexpected

Post support questions about your JD350 and newer crawler here
Post Reply
User avatar
bobdoss
40C crawler
40C crawler
Posts: 17
Joined: Tue Jul 03, 2007 8:03 am

JD 350 loader - boom & bucket hydraulics quit unexpected

Post by bobdoss » Mon Jun 20, 2016 9:56 am

I just bought my second John Deere 350 loader. When I started it for the first time, it ran for about 15 minutes, with normal raising, lowering and down-pressure on the boom. After about 15 minutes, the boom would not raise more than a few inches.

I swapped the hydraulic pump (known good) from my first loader, verified the oil level in the sight glass, then traced all of the hoses to be sure they were not crossed.

One-by-one, I loosened the fittings at each end of each cylinder, and found a spurt of oil at the expected fitting when I operated the control lever.

I opened the oil reservoir, discovered the paper filter plugged, and the wire mesh filter absent. The can and the locking “wing nut” were lying loose on the bottom of the tank. I removed the paper filter and put the cover back on without the filter. I am ordering both filters, but am not confident that they will solve the problem, since the problem still exists with no filters at all.

The pop-up valve on top of the reservoir does operate, but not very smoothly - I plan to shoot it with some WD40. But there should be no reason for it to pop up with the filter removed.

Finally, the oil in the reservoir is milky, suggesting wáter in the oil. Although bad for the system, it seems that I should still get SOME response from the cylinders, since water (like oil) cannot be compressed. I am also going to check for air leaks in the suction line, since the oil is so milky.

Any and all suggestions would be VERY welcome - I am stumped, and don't know what to try next.

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 61 guests