O.T. IHC PAYSTAR 5000 AIR BRAKES

lenray · Jun 19, 2023

Have this 1978 Paystar 5000 IHC 10 wheeler dump truck. Fixed all the air leaks and now the air brakes on one side of the drive axle have the wheels locked up.
Don't know how to adjust these--see there is a threaded rod with a lock nut and a 3 position clevis that goes into a part....How do I BACK THESE OFF ????
Thanks for any help.

used red MN · Jun 20, 2023

IH trucks particularly the extreme heavy duty Paystar line may be kind of odd balls. If it is like most of the truck with air brakes of that era the part you are looking to do the adjusting on is called the ..slack adjuster.. In the link the 3rd diagram down the example to the right ..type II.. is the most common type I came across working on a few hand fills of heavy duty trucks in the 80s and 90s. The slack adjuster is where you adjust the brakes. I believe the adjuster hex size was 9/16 inch wrench. Around the hex is a locking collar you push in and then turn the adjuster hex to tighten or loosen the brakes. I believe it follows regular bolt thread left loose and right tight. I suggest you first try adjusting one that already is released to get the feel of how they work. If the adjuster has pressure on it they can be difficult to turn.
Link to slack adjusters.

r.w.b. · Jun 20, 2023

1 silly question ,did you accidently get the 2 air lines turned around when you fixed the leaks? apply parking brake see if suspected brake is unlocked other 1 locked then push yellow knob in check em again.
when i adjusted brakes id turn that adjusted nut to snug,back off quarter turn maybe tad more never a half. make sure the locking collar pops out when done

Fritz Maurer · Jun 20, 2023

10 wheels means you have 2 axles in the back, which one is it? Does it have spring brakes in all four corners or just one axle? The question being are you getting pressure to release the spring brake, or if so, the diaphragm could be ruptured and would never release the brake, but this leak can be plainly heard. Or, if this malfunction is occurring on a non-parking axle, you may have a line crossed upstream somewhere. Another possibility is something broke inside the wheel and the S-cam over-center and jammed.

Fritz Maurer · Jun 20, 2023

Another possibility is you may have automatic slack adjusters... to back these off you get a sharp screwdriver and pull out the spring loaded button in the center of the adjusting bolt, and then it can be loosened.

showcrop · Jun 20, 2023

The adjusting screw head is only around 1/2 inch ad can easily get covered with grease so that you may not readily see it.

RodinNS · Jun 20, 2023

If you're considering putting this thing on the road, the best advice for you is hire someone qualified to fix the brakes. If you touch it, and it fails... and kills someone... you're going to be held responsible.
Beyond that, any number of things could be wrong. Without knowing what you did it's hard to give you good advice. Assuming that the air lines are correctly connected, you could be dealing with shoes that are simply rusted to the drum (most likely) or a broken spring in the brake chamber that is preventing full release of the brakes. If this is a problem that just developed since you worked on the air lines, then I'd wager you reversed a maxi line for a service line on a can... I would really suggest you get someone qualified to look at it tho.

Rod

Welding man · Jun 20, 2023

Did you grease the S cam bushings. If the truck has been parked a while. The S Cam could be stuck. Are the shoes and drums worn to where they have over cammed and locked up? A truck that old would not have auto slacks, unless someone put them on it and I doubt that.
People hate them because after a while they don't work right and still need to be adjusted manually. Air brakes are safe, simple and easy to work on once you learn how. I am a DOT certified air brake repairman.

2SteveWI · Jun 20, 2023

That truck is old enough that it may have Wedge brakes. S-cam brakes are by far the most common. Agree with the other posts that advise to find someone experienced to look at it. A picture would go a long ways. Steve.

counterclockwise · Jun 20, 2023

If you dont get this figured out soon contact me. I dont think you are too far away and Id be glad to stop and take a look. You are near Clare, correct.

lenray · Jun 20, 2023

FOUND THE PROBLEM--Many thanks for all the suggestions and help..It was a valve under the tredle sp. that was sticking....thanks again.............

caterpillar guy · Jun 20, 2023

Lenard Call me if you like. 989 413 5684 Those adjust with either a 7/16or a9/16 wrench on the side of the slack adjuster not the threads on the rod. IT has a ring you push in to turn and then pops back out to lock the screw from turning. Same on all 6 wheels If it happens to have wedge locks they are a whole different animal and are usually rusted up so you have to heat them with a torch to get them loose then do it each time you want to adjust brakes if it is not done on a regular basis and well lubricated each time they are worked on. Been 30 years since I worked on wedge lock brakes. Once loosened up they adjust reasonably well. The pedal valves are known to stick on trucks if not used on a regular basis also. Right under the pedal there. Squirt your favoite juice in ther and work on it. Some times you can get the pedal up off from the valve and work it loose that way. IF you canb get the little plunger deal out that is on top polish it up with some Emory cloth then lube well and check if it works freely.

O.T. IHC PAYSTAR 5000 AIR BRAKES

lenray

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used red MN

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r.w.b.

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Fritz Maurer

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Fritz Maurer

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showcrop

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RodinNS

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Welding man

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2SteveWI

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counterclockwise

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lenray

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caterpillar guy

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