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JD650H dozer major hyd oil leak under pump/ transmission

NY Roughneck · 2018-09-09 10:31

Good Morning, I have a JD 650H that developed an major hydraulic oil leak the appears to be under and near the pump. Can not get a visual on the leak. The leak is significant empties a 14 gal reservoir in 30-45 seconds. Filling the trans hyd oil tank can only move the machine about 10 ft before out of oil. My problem is the machine is off road in the woods and we're going to have to repair it ourselves. We have raised the seat and removed the floor panel and two inspection covers from underside. We cleaned most of the oily mud from the area Can not get a visual on the leak. Hoses appear to be dry. Is there a hard line in the area under the pump? Any ideas on how where to start? Your assistance is greatly appreciated.

Replies5
  1. #1Bls repair2018-09-09 16:10

    Sounds like a main hydraulic line .Drop the belly pan and see what you can find.

  2. #2NY Roughneck2018-09-09 19:37

    We removed two inspection covers each about 8" x 20" I don't believe there is any other removable covers than the 8" x 8" engine oil drain cover? Thank You Much for your assistance.

  3. #3mestizo2018-09-13 22:31

    Just sitting in neutral the transmission charge pumps dump into the hydrostatic cases. Thats a good amount of flow and could drain the reservoir. Its your transmission reservoir thats emptying? Is your hydraulic reservoir fine? Could be a crack in the transmission pump housing. There is a charge relief valve on the bottom of the front trans pump and a jumper hose that runs to the bottom of the back pump, make sure everything there is snug. Can you get your eyes on the leak?

  4. #4JD955SC2018-09-14 21:47

    What about full on belly pan removal (never worked on a Deere but I’d think they would have a larger pan than the small access plates) Be careful they are heavy and awkward.

  5. #5OldMachinist2018-10-09 21:33

    I'm really sorry that I can't help you with your problem, but I'm hoping you can help me with mine. Just got a JD 450H and was wanting to change the engine oil. Looking up at the oil pan from underneath and through an access hole in the oil pan cover, there seems to be one drain bolt sticking straight down near the rear of the oil pan and another drain bolt sticking straight out the back of the oil pan, just a few inches from the vertical drain bolt. Can you tell me if these are different fluid drains? Or which to remove to drain the engine oil? Thanks...an I hope you got your hyd leak repaired.