m109a3 breaks lock up idling

[Redfive0]

I've Scanned through forms for awhile this morning. I could use a helpful point in the right direction. I have a 1966 m109a3 that when I run the the engine even at an idle for a few minutes the truck will apply its own breaks and lock up. this started occurring after we had paid someone to work on a truck clearly didn't know that much
about deuces. the wheel cylinders Was changed the shoes were changed and the master cylinder.

Any ideas where I should start?

 

[doghead]

Do they lock up without ever touching the brake pedal?

If so, I suspect your air-pack is leaking internally.

To test this, remove the plug from the back of the air cylinder portion of the air-pack, and hold a finger over it and see if air is building up. There should not be any air build up.

Another possibility is the master cylinder is not adjusted properly. This would more likely be the issue if you apply the brakes and they stay on but it could be the issue even if you do not apply the brakes.

Perhaps everything recently done, should be gone over and done again by the book(TM).