JD 3720 Hydraulic pump return hose assemply leak

[marshallcro]

I have a slight intermitting leak in the return hose assembly in a JD 3720. It looks to me like its around the hose clamp of the vertical return pipe but its hard to tell. Can the pumps themselves leak? Has anyone changed this part and can you give me some advice in replacing it and reducing contamination of the fluid when opening the system? Also could you tell me the amount of fluid that is needed from the ADD line to bring it up to the FULL line on the hydraulic dip stick? Is there a specification for the X marks in the middle on the dip stick? I'm afraid of over filling it and ending up with more work to bring it to the proper level. Thanks in advance?

 

[mike48130]

Well assuming that is close to my 4410/4210, I have replaced them. Mine has the 2 pumps and one molded hose going to both. I replaced mine when I did a pump rebuild on the 4210. It wasn't hard, and mine is on top of the pumps, so wasn't much fluid loss.

The pump can leak. It is stacked plates with O-rings between them. There have also been incidents with these types of pumps to crack and leak.

Where and when does it leak? If it leaks when it is running, then probably not the intake hose.