775 nh

[derbynutman]

Hello, I have an nh 775, all hydraulics work and drives work except for one side is really weak in reverse. It seems to work ok when cold for a few minutes. Forward works fine all the time. what could be the problem? What type and weight of fluid should I be using? Thanks

 

[frogfarmer]

Your hydro pumps have releif/replenishing valves for each direction and for each side 4 total. An easy test if you can get to the valves is to swap them and see if the problem follows the valve. If it follows the valve replace it. 10w oil is what is recommended and everybody has their preference. I run 10w30 engine oil in all my equipment hydraulics so its easy to service and remember. The dealer will tell you whatever oil came in it.

 

[derbynutman]

Your hydro pumps have releif/replenishing valves for each direction and for each side 4 total. An easy test if you can get to the valves is to swap them and see if the problem follows the valve. If it follows the valve replace it. 10w oil is what is recommended and everybody has their preference. I run 10w30 engine oil in all my equipment hydraulics so its easy to service and remember. The dealer will tell you whatever oil came in it.

I played with it today and got it to work, dont know how.. I ran it full throttle moving the bad side stick several times back and forth real fast, and it loosened up and works fine with lots of power.. I dont think it was good for it and maybe it will only work for a short period. could there have been something stuck and it freed itself. Thanks for the reply..Im also going to change the oil/fluid and filters tommorow

 

[frogfarmer]

I played with it today and got it to work, dont know how.. I ran it full throttle moving the bad side stick several times back and forth real fast, and it loosened up and works fine with lots of power.. I dont think it was good for it and maybe it will only work for a short period. could there have been something stuck and it freed itself. Thanks for the reply..Im also going to change the oil/fluid and filters tommorow

Given how you fixed the problem I would make sure you dont have a chain issue. Both tires on each side should pull when the machine is driven against an immovable object(large tree). It is possible the releif valve got some trash stuck in it and continued flow cleared it out. I would give the unit a good going over before I cleared it for use.

 

[derbynutman]

Given how you fixed the problem I would make sure you dont have a chain issue. Both tires on each side should pull when the machine is driven against an immovable object(large tree). It is possible the releif valve got some trash stuck in it and continued flow cleared it out. I would give the unit a good going over before I cleared it for use.

Thanks for the reply, I checked the chains and there fine...(put in new a year ago) everything is working fine for now. I ran it yesterday all day with no problems, hope it was a stuck valve that cleared itself... thanks again for the help..I changed the fluid and put in 10w-30. will this oil be ok?

 

[frogfarmer]

Thanks for the reply, I checked the chains and there fine...(put in new a year ago) everything is working fine for now. I ran it yesterday all day with no problems, hope it was a stuck valve that cleared itself... thanks again for the help..I changed the fluid and put in 10w-30. will this oil be ok?

10w30 is fine I run it in everything and buy it by the barrel. There have been pages written on the Hyd vs 10w30 vs the factory "Gold". I have never seen a problem but I will admit I havent seen everything.

 

[papow22]

10w30 is fine I run it in everything and buy it by the barrel. There have been pages written on the Hyd vs 10w30 vs the factory "Gold". I have never seen a problem but I will admit I havent seen everything.

Just to put my nickel in I too use 10-30w oil in most of my equipment,but the Komatsu tractor crawler requires 10w motor oil.No aw64 hydraulic oil.I know it hard to come by over here you have to pay premium price.

 

[PeteL775]

I know this is an old thread, but I have and old machine.... I have the same machine and the same problem, however every thing on mine says the hydraulics run ATF. Are the pumps and motors filled separately from the hydraulic reservoir? I still have not gotten up the nerve to pull the valves yet, but that is my next move. Any tips or tricks would be greatly appreciated.