Heavy Equipment Forums Heavy Equipment Community

Cat D4H Oil Line To Radiator

RodC ยท 2026-02-23 18:22

Im working on an 1989 D4H 8PB0 SN There is a steel line running from the left bottom of the radiator to the right side of the engine for the oil cooler in the radiator. There is a hole in it. From what I can tell the newer models have a fitting and a rubber hose. I can't find any info in the parts manual for this line, steel or rubber. Any info you can provide would be greatly appreciated.

Replies10
  1. #1pittsburgh cat man2026-02-23 18:36

    Look under transmission

  2. #2RodC2026-02-23 18:37

    Here is an image from the service manual. This must be a newer model, it shows a hose where I have a Steel line.

  3. #3RodC2026-02-23 18:39

    I saw that, but Im a bit confused. It seems like engine oil is leaking. It may be tranny fluid. Ill trace it back a bit further tomorrow.

  4. #4pittsburgh cat man2026-02-23 18:50

    This is 8pb4000 up

  5. #5pittsburgh cat man2026-02-23 18:51

    is it possible oil is leaking from engine and just following down the line??

  6. #6Nige2026-02-23 18:53

    Is the 8PB machine S/N above or below 04000.?

  7. #7RodC2026-02-23 18:56

    No, I can see the hole in it.

  8. #8RodC2026-02-23 18:57

    Below 32XX

  9. #9RodC2026-02-23 19:01

    Dang it, I saw that exact diagram on the cat site yesterday, now I cant seem to find it under the tranny section.

  10. #10RodC2026-02-23 19:04

    It's under Cooler GP Thanks guys for getting me in the right direction. I thought it was weird that there was an oil cooler on the engine and one in the Radiator. You guys always help me out.