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JD 4.5L TD oil pressure switches/sending unit

hootowl ยท 2025-11-09 18:48

I have a 1928 Model A rat rod believe it or not with a 4.5L TD. I'm replacing the long oil pressure switch with a new one cause they always leak and this one is leaking... already replaced once. What is the canister looking one. Yes I have the gauge so I'm assuming the canister one is a variable sender for the gauge but what does the other one do? Shut the engine down?

Replies4
  1. #1csthompson122025-11-09 20:40

    I don't have an answer to your question, but would love to see more pics of the rat rod. What does it use for a transmission?

  2. #2hootowl2025-11-09 21:10

    That's hilarious... everybody always answers with that question. Powerglide with a custom adapter.

  3. #3Simon C2025-11-10 15:19

    The cannister style one is the variable resistor that causes the oil pressure gauge to sweep up and down. The small one is usually a 15PSI or similar light extinguisher for the dash light, if I recall correctly. Some times they are dual terminal switches that when the pressure gets to low the fuel solenoid drops out. Simon C

  4. #4hootowl2025-11-11 11:36

    I am using the original control panel the engine was connected to and it's got both a gauge and a light. I'm gonna see if I disconnect the skinny sensor if the engine shuts down.