air brake question

the red one only parks the trailer, the yellow the tractor.

 

most of them if you pull the yellow, the red one pops out as well.

In the winter I usually put my thumb on the red one, so as not to apply the trailer brakes. They can freeze on if wet.

 

The reason the red one says not for parking is because the yellow one is the one intended for parking. The yellow and the red really do the same thing although the yellow sets the tractor brakes and the red sets the trailer brakes.. if you pull the yellow the red will pop out also(it should) but if you pull the red by its self the yellow stays in.. When i set my parking brake I almost always only set the tractor brakes holding the red button while I pull the yellow.. only under special circumstances do I set both.. I hope I did not confuse you...

 

It's not to be used for parking because at one time the trailers had single diaphragm brake pots & after the air leaked out the brakes would not be applied. There are still some trailers like that out there. This is also why in training you were probably told to back up close to the trailer, then hook up & supply the air before trying to back under it. It's kind of funny to watch somebody try to hookup to one of these types of trailers as it takes off away from them.

 

Good answers above.

Also, friendly hint: When parking, set the trailer brake 1st (red), give a small (gentle) tug then set the tractor brake (yellow). This will set tension on the 5th wheel lock and prevent some yahoo from pulling your 5th wheel release while you doing business in the truck stop. You can do the same thing with your Johny brake if equiped.

I drove for Swift and found that some clown had pulled my handle while I was grabbing breakfast. Lucky for me, I always do a walkaround. Just want save others the problems of a dropped trailer. And yes, I was parked in a slot, not the fuel island.

 

the red button is for trailer air supply---goes to the red line at back of truck--trailer air supply
the yellow button---when out--- exhausts air from the spring brake chambers allowing the spring to to apply brakes on all of the axles equipped with spring brakes
if you pull out the yellow button,the red will pop as well---and both the truck and trailer spring brakes will apply-- and when you drop the trailer after unhooking ,you will have the yellow in,allowing truck to be moved--and red in causing trailer brakes to be on(air released)

sorry i am not real good at explaining--but the moral of the storey is that the red button is really trailer supply
but if you pull yellow out while holding the red in,only the truck brakes will apply
this is what is normally done in winter so that your trailer brakes dont freese on while parked (probabely dont want you doiing that in school)

 

They were called Maxie brakes. If you didn't hook up the lines the trailer would take off on you while you were trying to back under it. Another way around this problem was to use a big piece of lumber behind the trailer tires, or a curb, or what ever. I haven't seen that setup in years. Another way was to let the trailer air build up then apply the brakes, then back under it. Sorry it's been a long time since I have worked with type of trailer. Hope I explained it right.

 

Maxie brakes are what is used now. Maxie Brakes link

 

Or what ever those brakes were called, I can't remember. Trucker 101 you've been at it as long as I have so what is the system called. I thought it was Maxie.