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100 R2 hose on a Hitachi UH 083?

Planedriver ยท 2017-08-11 15:44

So on what I think is a return/bypass hose/steel line combo someone tore the threads up. It seems they forced a SAE pipe thread fitting into a BSPP female fitting. There are 2 lines leading to each of the drives are good so far. The problem 1/2" line comes off the bottom of the center joint to a Tee, then each branch goes to the top of each drive motor. My question of many is: If I replace the steel line with SAE 100R2 hose will it work or is there 5 - 6K pressure on that line like there is on the drives? Other options include brazing the hole that always rusts through under the clamp and welding a new coupler on.

Replies6
  1. #1GregsHD2017-08-11 22:23

    Sounds like that line is just case drain for the motors, so that hose will work. Better option then trying to weld oil impregnated pipe!

  2. #2Planedriver2017-08-11 23:35

    Thx Greg... seemed to make sense to me but wanted a second opinion.

  3. #3Welder Dave2017-08-11 23:52

    Find out the pressure first. What had the BSPP thread?

  4. #4Planedriver2017-08-12 00:00

    What I'm calling the return line had a female BSPP swivel fitting factory welded to the pipe. Interesting to note that a 1/2", 4090 psi rated hose about 2 feet long joined the pipe and center joint. As far as finding any pressure.... I have scoured the service manuals with no luck.

  5. #5Welder Dave2017-08-12 10:16

    A spec. sheet should say or call a dealer and ask.

  6. #6GregsHD2017-08-12 10:55

    On the top side of the rotary manifold (swivel) where does the 1/2" line go, should go to a return manifold or direct to the reservoir. There is no pressure spec for case drains that I know of, you want the least amount of pressure possible otherwise the shaft seal on one or both motor(s) will blow out. If in doubt just use 4 wire hose.