Heavy Truck Mechanics - Question about air brakes

[malbojah]

I drive an late 90's International 4900 for a local disposal company. Since I've started there, the air brakes on this truck have always sucked, no matter how much adjusting is done to the slack adjusters. The truck brakes straight, but the front and rear brakes do not work together.

If I apply regular pressure to the foot valve, I can see an approx 5 psi drop on my air gauge and the front brakes come on - but no rear brakes and no brake lights. I have to continue applying increasing pressure to the foot valve until what feels like a barrier is breached. At that point, I'm applying probably 25 - 30 lbs of force on the foot valve and a sudden spike of 20 psi is registered on the air gauge. The front brakes remain applied (not locking), the brake lights finally come on, and the rear brakes are engaged. If I leave the heavy amount of pressure on the valve, the rear wheels quickly lock up. If I'm at a stop and apply enough pressure the engage the rear brakes, the foot valve feels like it's trying to push me back into the chair.

I'd ask the shop mechanics to take a look at it, but right now they're swamped with snow removal stuff to be going on a goose chase. If I could tell him "this is probably what's wrong" he might be more receptive to working on it sooner

 

[skyking]

It can be any number of things. If it has a trailer hookup and hand brake, it can be the tractor protection valve. It can be the foot valve itself.
Another suspect is icing. If you could get it in a heated shop overnight and drain it out good you might find that one yourself. Regardless of all that, braking and safety should be an absolute priority. I would not drive the truck the way you describe it. Not worth it at all.
How would you feel if you hurt somebody? What would the boss think? I say fuck that shit. Be the really squeaky wheel on this one.

 

[olds]

Sounds dangerous and illegal. Since you know about the condition, when you hurt someone, prepare to be butt raped in court.

Has the truck passed BIT or is the BIT even current?
Drain all the water out, adjust slack adjusters properly. Be sure to chock wheels.
Do a proper COLA.

https://www.youtube.com/watch?v=smS9aJidlrc

 

[OILFIELDTRASH]

I'm actually a truck driver. I have no idea what's wrong with that truck. What I can tell you is that you should not drive that truck. You are responsible for that truck once you leave that yard. I would tell them you're not comfortable driving it as is. Write it up on your daily inspection report. That puts the responsibility on them. That puts it in writing and I promise you that they will not let the truck leave the yard once it's in writing. They have to keep the daily reports for the DOT when they get an audit.
Secondly you should be looking for a better job that takes care of their equipment and drivers. I won't work for a company with old ass equipment. Those places are for people with little experience, bad driving records, or don't know better.