M602 hydraulics

[Jay Liedman]

This is perhaps a really ignorant question, but here goes: I have a Moline M602. I rebuilt the engine, and made a few other repairs, and it runs really nice. HOWEVER, the rear hydraulic arms do not move at all when I manipulate the levers. I have added fluid, but no change. I am assuming the pump must be bad, but I am quite unfamiliar with the hydraulic system on this model, and there are some extra control levers I really do not understand the purpose of. Any advice before I pull the pump off?

 

[Howard H.]

I haven’t run my 602 in a while, but remember the hydraulics were pretty weak. And the pump was heating pretty bad, as I recall, so I suspected an internal oil leak…


Howard

 

[JOCCO]

Advice yes, get a manual and trouble shoot it. Might not be the pump.

 

[MMDEL]

Yes!!!! Jocco is right, get a manual so you can find out what each lever is for before you start taking things apart.

 

[Alan K]

Just asking, have you changed they hydraulic filter? Does your power steering work, remotes for a cylinder?

 

[Jay Liedman]

Just asking, have you changed they hydraulic filter? Does your power steering work, remotes for a cylinder?

Filter has been changed. No power steering on mine.

 

[Alan K]

Filter has been changed. No power steering on mine.

That is interesting. I have never seen an M602 without power steering. I thought all of them had it. Where are you from?

 

[T.R.K.]

Not familiar with a M602, but I recall getting the hydraulics to prime after replacing the filter in a jetstar3 required pouring oil in the line between the filter and the pump. The filter was mounted vertically on the left side beside the 3 point housing.

 

[Lyndon - AB]

This is perhaps a really ignorant question, but here goes: I have a Moline M602. I rebuilt the engine, and made a few other repairs, and it runs really nice. HOWEVER, the rear hydraulic arms do not move at all when I manipulate the levers. I have added fluid, but no change. I am assuming the pump must be bad, but I am quite unfamiliar with the hydraulic system on this model, and there are some extra control levers I really do not understand the purpose of. Any advice before I pull the pump off?

Check the relief valve in the main valve block. I had really weak hydraulics on my M602, and like you, assumed it was the pump. Replaced the pump, lo and behold, no change. Dug deeper, and found that the piston in the relief valve was stuck partially open. Popped it out, cleaned it up, put it back in making sure it can slide freely in the bore, and presto, fully functional hydraulics!

I don't have a 3 point hitch on mine though, so likely some differences in the layout of the hydraulic system.