Hi all I have a 1984 John Deere 310B backhoe. I just purchased this machine and figured I would change the hydraulic fluid, hydraulic filter, transmission filter and hydraulic sump screen. This machine ran just fine with great responce and cycle times. I drained about 8 gallons of fluid from the machine and the specs say it holds around 20 gallons so I figured I would increase the filter changes if I noticed oil problems. Anyways everything went well and I top off the fluid with John Deere HyGard. I started the machine and all my function were slow and severe chattering. I took the machine for a ride and everything worked well including brakes, steering, forward and reverse. The problem is the operation of the outriggers, front and rear buckets and boom operations. It seems like there is air in the system. Writing this I am wondering if I am sucking air at the filter housing. Anyways I hope you all can help. Thanks!
This morning I removed the hydraulic filter to make sure the gasket was seated properly (all is good). Started the machine and checked the fluid level and there was lots of bubbles on the stick. I went to the hoe and began bleeding the lines, no luck still chattering and sluggish. The valves controlling the backhoe operations give a rattling sound when used. I don't understand how the air got introduced as I did not remove all the fluid only what was in the transmission case.The only air would be from the filter housings. I failed to mention in my first thread that I did replace a rubber hose that is between the transmission case and the hydraulic filter housing. This hose is about 4" long and held in place by hose clamps and is located at the bottom of the transmission so it gets flooded when filling the system. Any help with this problem would be greatly appreciated.
I figured it out. When changing the filters and fluid I took the plug on the bottom of the hydraulic filter assembly off which actually holds the relief valve that is spring loaded. The spring dropped into my catch bucked and I fished it out with a magnet. I reassembled and had the problems mentioned above. I looked through my manual and discovered that there is a valve (about 3/8" in diameter with around a 3/16" stem) that this spring holds against its seat. I went fishing with my magnet again and found the valve. I installed the valve and all is normal (no bubbles,no chatter, smooth operation, great response and cycle times). So if you run into a similar situation before condemning a pump or something really expensive make sure this piston is held against it seat with the correct force if not it may create the same havoc I experienced (springs wear out). I hope my mistake can help someone else out.
Sorry we couldn't help and thanks for the update. I should have been able to at least point you in the right direction. Sometimes you have to wait a long time to get Deere advice here, some of the members don't check in very often, and not a lot of experience going back that far either.
Thanks Delmer for the reply.