revbill
Member
- Joined
- Jul 9, 2011
- Messages
- 17
- Location
- columbus ga
- Occupation
- heavy equipment mechanic for a medium size rental
I am working on a JD 120c. this unit has a Hitachi pump system.
This piece of equipment has been working just fine until the other day when it quit any and all hydraulic functions. I found that the piggyback or charge pump had sheared the pump input shaft. I replaced the pilot filter housing, that seems to have a sort of relief valve in it? I replaced all the hydraulic filters and checked the return to tank line from this pilot filter housing, it was clear. I replaced the pump, purged it ,fired the unit up and snap goes the small, charge pump shaft. The local JD dealer doesn't have a clue, they came out, checked it, put a pump in it, and the same results, broken shaft. Does that pilot filter housing really have a relief in it or should I be looking further up the system? Any ideas? or does anyone know how this system works? Getting expensive. Thanks for any help. Bill
This piece of equipment has been working just fine until the other day when it quit any and all hydraulic functions. I found that the piggyback or charge pump had sheared the pump input shaft. I replaced the pilot filter housing, that seems to have a sort of relief valve in it? I replaced all the hydraulic filters and checked the return to tank line from this pilot filter housing, it was clear. I replaced the pump, purged it ,fired the unit up and snap goes the small, charge pump shaft. The local JD dealer doesn't have a clue, they came out, checked it, put a pump in it, and the same results, broken shaft. Does that pilot filter housing really have a relief in it or should I be looking further up the system? Any ideas? or does anyone know how this system works? Getting expensive. Thanks for any help. Bill