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Looking for advice on a Grove RT 422

Tugger2 ยท 2025-07-09 23:23

A customer of mine has a this Grove Rt that has sat for 2 years . They have started it periodically but never actually ran any functions. It was parked running and functioning properly im told. As it sits now it will steer ,swing and the line runs up and down. Boom will not move up or down ,no telescope and the out riggers dont work. They have no manuals for the crane or the Hirshman LMI. Im going to encourage to get the right books for the machine first. Ive run this machine for them a few years ago ,just started it and ran it. But being a conventional guy this issue has me stumped. Just fishing for ideas before they start digging deep into it. Thanks in advance.

Replies6
  1. #1crane operator2025-07-10 06:54

    Does it have a disconnect lever for road travel on the pumps? Should be a short lever at the gearbox. Disconnect makes them road a little faster, but I would think it would disconnect winch also. Typically if the lmi isn't set or in bypass, you won't have cable up, boom down, or telescope out. They usually have 3 pump sections, swing, telescope and outriggers together on one section, then boom and winch on the other two. On RT s there's typically one pump that does steering, and usually some other functions, then the pump disconnect pulls out another pump that does boom and winch.

  2. #2crane operator2025-07-10 06:57

    Disconnect lever is usually between the turntable and the engine compartment. Either sticking up out of the deck, or accessed from a hole cut in the deck.

  3. #3Tugger22025-07-10 09:24

    Yes it does have a disconnect on one pump. Checked it and you can tell by sound when the pump is engaged.There seemed to be a lot of air running thru the pump at first. Going to call the parts guy today and look into manuals. I thinking this might be a pump problem stemming from some unreported incident,all i have got from the owner is that it was running fine 2 years ago.

  4. #4crane operator2025-07-10 10:17

    They can have the drive collar break/ strip out. It's between the pump and the gearbox.

  5. #5crane operator2025-07-10 13:02

    When I had a drive coupler strip, it would jump the hose a little, acting like it was building pressure/flow, but it would slip the teeth.

  6. #6Tugger22025-07-10 21:36

    They are looking at the main pump ,we will see what developes.