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IH 2574 Trailer brake plumbing

charles walton ยท 2022-01-07 19:16

I just purchased a new to me '79 IH 2574 and it is a straight truck with a log bed,has no trailer brake set up, can anyone tell me what all I need to buy to put trailer air hookups?And is there a good tutorial video for this somewhere?

Replies13
  1. #1Shimmy12022-01-07 22:03

    It's not hard to do, I did a couple 25 years ago. The Johnson bar is an International-specific part that bolts into the steering column. You need a trailer brake push/pull valve, a tractor protection valve, glad hands, air line, and, most importantly, a schematic so you know what needs plumbed where. It's not hard, just time consuming, and it helps tremendously to have an identical truck that has the plumbing to look at as you go.

  2. #2Jonas3022022-01-07 22:03

    HeavyEquipmentForums That thread ended up covering it pretty well

  3. #3charles walton2022-01-07 22:07

    Thanks

  4. #4charles walton2022-01-07 22:08

    Thanks

  5. #5charles walton2022-01-08 09:04

    I've been reading this thread,made it through 6 pages so far,it is very helpful and it's made me want to seek out a good shop to do this IF I CAN FIND one that seems to know enough to do it and the estimate is not over my budget. Which means I'm probably going to spend the winter days trying to wrap my head around it and do it myself. Thanks again.

  6. #6charles walton2022-01-08 18:50

    This valve body has some plugs in the service lines like it might have had some lines teed into it before.

  7. #7Shimmy12022-01-08 19:47

    That valve has nothing to do with a trailer air supply. The tractor protection valve gets its air directly from the reservoir, and sends air out the emergency side when you push the trailer button in, and sends air out the service side when it gets a signal from the truck brake tredle valve, or the Johnson bar (trolley valve).

  8. #8charles walton2022-01-18 12:41

    I'm totally dumb on this subject but I'm getting the parts together to do this, starting at the dash. I'm looking on fleabay for MV3 valves and Bendix has several model numbers. What should I buy for the 79 2574 ?

  9. #9Truck Shop2022-01-18 19:13

    MV3.

  10. #10Truck Shop2022-01-18 19:19
  11. #11charles walton2022-01-19 06:01

    yessir,I got the MV3 part but Bendix has so many different models I was hoping someone would know which one is better suited for use on the IH 2574.

  12. #12Shimmy12022-01-20 00:00

    Well, IH didn't use an MV3 back then on the vocational trucks. If it was factory, the trailer valve received it's air supply from the truck valve, AFTER the brakes were released. We replumbed our trucks to have constant air so we wouldn't have to set the trailer brakes every time we parked. I think the MV3 valve is the way to go, I'm just not sure if you're going to have the room to put it behind that dash panel that holds the current park brake valve. If it has a front brake limiting valve in there too, that is going to be a problem.

  13. #13Birken Vogt2022-01-20 00:48

    https://www.suspensionspecialists.com/techinfo/Bendix_Brake_Handbook_2009.pdf