hi guys I need opinions... I have a John Deere 8875the model is from 1996 the motor runs strong and the machine is still tight has way too many hours for the meter to read and a horrible repaint on it. the machine runs my badco excavator attachment without a problem on auxiliary controls. everything worked wonderfully until 3 days ago. The machine runs strong for about 10 minutes until it warms up then I lose proper controls of the boom and buckwt..they start to hestitate at first then shutter an inch at a time under load.they won't left off won't back down won't do anything properly then when I take the weight off them they move slowly back to the regular seated position. When the unit cools it works well again. It is not overheating and all filters and fluid s were changed. I called the Deere shop and a service rep said by the symptoms it maybe a solenoid (part mg86507510) or solenoid support ( part mg 86507506) but he said no promises. He spoke on the phone that I had to lift the cab to change these out and gave me instructions over the phone how to do it which didn't make sense to my setup so I started to question his judgement. Does anyone have input with more certainty? It would be greatly appreciated. I would hate to buy these parts and install them to find out it doesn't help. Thanks for any input you guys have.
Hi ed n i would like to help you out with your problem,but you gonna need some especialty tools as we walk along with the repair. Have you ckd the hydraulic filter yet. Remov it and see if theres any metal shavings,if so than you have a pump restriction issue,wich in fact can cause some bad internal cloggage.By the way you have to cut the filter open in order to take a good look into the filter:usa
Ok, thanks for the advise. Luckily I saved the old filter. I will cut it open and have a look tonight.. fyi, the symptoms are getting worse now. Still works fine when cold but now when hot, sometimes the controls work backwards. If I idle it down it works ok but of course no power . Any thoughts?
If the controls work backwards now at some times i would say that internal ck valves that take care of the boom and bucket blew up or are about to go completely disabled definitely we need to start cking on the filter first wich is one of the first steps to tackle this type of erratic hyd.problem.
One of my guys cut the filter open this morning. Besides a little shavings from the cut it doesn't look like any metal shavings were present. What should I check next? I'm ready to work on it all day today if we can resolve it
Hi Ed N next item i would ck be the drive pump control shaft seals for wetness if so,you have a leak and got to be corrected.You may also want a ck the reservoir oil tank see any foaming forming,there has to be an air leak on the system.Once you know that there is no air leaks either on the suction hose and no other visual leaks means two things,relief valve ssetting is off or the pump is likely to be at fault.the other components you may want to ck is for a weak relief port at the main control valve.Good luck.Postdata you gonna have to use a hidrogauge in order to adjust pressure values if you dont you may end up blowing a hose or an internal seal.
Thanks for the info...after inspection I found no wetness around the control shaft seals and there is no foaming. Where is the relief valve ? Or what does it look like. I will see if I can purchase a hydrogauge somewhere. In the meantime. I order a new pump aftermarket online that I should have tomorrow just in case... but fyi , this model has 2 pumps side by side, how would I know which one has gone bad? If I need to replace?