84 310B bachoe slow hydraulics

Hello,

I've been reading these forums for quite sometime and have gotten good advice from them.

I just recently bought an '84 John Deere 310B backhoe with slow hydraulics. It has approximately 2200 hours showing on the meter. The steering and reverser seem to work fine. However the loader and backhoe seem slow and under powered. It chatters and vibrates a bit and make me believe the main pump is starving for oil. The previous owner had the main hydraulic pump rebuilt a few years back. I know I should probably test the pressures at the reverser and main pump from reading post, but wanted to start with changing the oil, both filters, and cleaning the suction screen. I have a service manual, but it lacks great detail on where the suction screen is located. Best I can tell, it is at the bottom on the case and is installed sideways or perpendicular to the length of the backhoe. Is it removed from the right or lefthand side of the machine? Can someone give me a picture or explain how to remove this screen? Is it located behind a fitting that a rubber hose attaches to from the sump to main hydraulic filter (horizontal filter)? If so, it appears the filter housing will have to be removed to get the screen out since the housing is directly across from this fitting and the rubber hose is only 4" long or so. Or can the screen be removed from the left side of the tractor by removing the fitting from that side?

Thanks in advance,
Cecil

You've got to get that screen out and check it. It's likely your problem, especially when the steering and reverser work fine. They don't need much flow.

I've got two 310Bs and have had the screens out of both. I don't recall from which side but I do know it wasn't any big deal, other then the oil mess. I did one last winter outside laying in the snow. That because my hydraulic filter cover blew off on a cold start (broke the bolt from pressure).

Note that the one filter cover that points straight down acts like a water-trap. If a 310B sits overnight in the freezing cold - it can freeze solid and dead-head the oil flow. So, you start the engine and it breaks that 1/2" bolt and blows the cover off.

Also, I suggest you order a new reservoir top hose from Deere and keep it on hand. This hose is near impossible to substitute and many 310Bs have the wrong hose installed. When it blows, it makes a mess. And, you're likely to stick the wrong hose on again and have trouble again. Both my 310Bs had the wrong hose and both blew. It's a small molded medium pressure hose and a molded coolant hose from NAPA can fit, but won't last long.

Elbow hose from hydraulic reservoir to cooler is Deerre # L35843 $11.70 3/4” molded hose, type 100R4, 300 PSI, 3.7” long with a 90 degree bend. Top of hydraulic reservoir.

By the way, you ought to get the OEM Deere service and operator's manuals for your 310B. I've got them both in .PDF files. You can have for free if you come up with a way to get them to you. Service manual is 70 MB and the operators manual is 13 MB. Many email programs crash trying to receive files that big. If you want, I can send by mail on a CD for a few bucks.

(reply to post at 17:13:06 10/29/11)

Click to expand...

LJD:Thanks for the reply. I'm not sure which 90 degree hose fitting your referring to. My 310b doesn't have a hydraulic reservoir, but uses the tranny as the hydraulic sump. Could you be refering to 300b maybe? If so, are your manuals for 310 or 300b?

In case someone ever needs to know in the future where the screen is located on a 310b. The operator's manual shows it but not the service manual. I ended up locating the screen. I got a little confused since the parts guy had told me that the screen would be located behind a plug that accepted the end of a 1/2" ratchet. Ended up finding out that it is located behind the fitting that attaches the small rubber hose from the hydraulic sump or transmission housing to the external hydraulic filter. I had a hard time figuring out how to remove the small 4" rubber hose. I finally discovered I had to loosen the external hydraulic filter housing and push it out of the way. I then barely had enough room to pull the screen out. The screen was almost spotless with only a few pieces of grass on it. Presumably from someone not cleaning a funnel out good enough before adding fluid.

I drained all fluid and changed tranny and hydraulic filters. Then topped off with new fluid. I still have the same symptom. Backhoe seems to be faster but doesn't have the power I think it should. It doesn't load the engine down when digging or you can't hear a relief valve pop, it just quits moving in an unpacked dirt hole. Oddly enough, the outriggers will lift the machine off the ground though. The front end loader and bucket move up real slow regardless of engine rpm. I can get the front end off the ground with the front end loader also but real slowly. I check the fluid on the stick and it appears to have bubbles on it like the fluid is foaming. I'm starting to think it is sucking air or a relief valve is hung open. Are there any easy things I should try first or jump straight to verifying pressures via the service manual? I might also just take it in to be looked at if there are no clear straight forward things to check. From looking at the flow diagrams, looks like fluid moves in high pressure from the main pump, to the accumlator, steering wheel, pressure control valve, then to the backhoe, or front end loader. I'm definitely not a hydraulic expert, but if backhoe functions at normal speed (but is underpowered) and front end loader is slow; I'm thinking maybe the pressure control valve could be the culprit. Anybody have any insight to how I should proceed next? Thanks again