New Job, possible issue with Trainer's truck

What kemosabi49 said makes sense if the trailers are set up that way. It does take time to fill the air tanks

 

When you pull the yellow button to apply the tractor parking brakes , the red trailer brake button will almost always pop out at the same time unless you hold the red button in with your thumb .

I don’t see a problem with this
Just do as the trainer says and keep your thumb on the red button so it won’t pop out .

Its almost like they designed it that way
You hook your forefinger behind the top corner of the yellow button and middle finger under the bottom corner , hold your thumb on the red button , and pull the yellow button out


If the trailer is plumbed so the air bags dump every time you pop the red button and apply the trailer brakes , then yea, it will take several minutes to inflate them and build enough air in the tanks to release the trailer parking brakes .

as for the brakes being grabby , I have no clue.

If the gladhand lines were hooked up backwards , the trailer parking brakes wouldn’t release at all .

 

You wanting to do the tug test with the trailer parking brake applied ?
Or using the trolly handle ?

assuming your tractor has a trolly handle or Johnny bar handle or whatever the lever on the right side of the steering wheel that activates the trailer service brakes is called .

my nephew is a driver and he never sets the trailer brake when they park at night ,
Said it takes too long to air it back up in the morning .

but they leave the rig idling All night ,

some trailers may leak down overnight if the tractor is not runnning

 

Honestly, you’re in training. It’s not your vehicle. Just follow directions and complete your training and when you get into your own vehicle bring any suspected problems to the shops attention. I’m just being real with ya.

 

$20 says it dumps the bags when you exhaust the air supply to the trailer. Then you have to wait for everything to air back up before the brakes release.

If the lines weren’t hooked up correctly you wouldn’t be supplying air to the trailer.

 

In winter when you see all the trucks with frozen trailer brakes after a storm you’ll be happy your trainer taught you not to set them every stop.. unless you’re on a big grade tractor brakes are enough if they are in proper operating condition. Aka no broken springs or misadjusted .

 

When I bought my trailer it had what sounds like the exact same problem. It took like 10 minutes for the brakes to release after supplying air, and light foot pressure would cause heavy braking. We had a mobile repair guy come out and he fixed it. The receipt shows part# KN26120, but yours might be different. It's listed online as a trailer brake control valve. The valve is installed on the trailer air tank. Hopefully this helps.

KN26110 is for service brake priority. It requires the trailer tank to be filled prior to spring brakes being released.