When should the tractor protection valve pop out?
The trailer air supply control (also called the tractor protection valve control) should pop out or go from “normal” to “emergency” position) when the air pressure falls into the pressure range specified by the manufacturer (usually within the range of 20 to 45 psi).
What happens to trailer brakes when the yellow valve is pulled out?
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..
Is red or yellow trailer brakes?
The yellow one controls brakes on all axles, the red is only for trailer, and the blue is only for the truck unit.
What color is the tractor protection valve?
red
The TPV is also called a ‘towing vehicle’ protection valve. The TSV has a red colored, eight-sided knob and is controlled by the driver. The driver opens (pushes in) the TSV when a trailer is being towed and closes it (pulls out) when there is no trailer present.
What color are air brake lines?
The red line is the air line for the trailer’s emergency brake. The green line is the electrical line. The blue line is the air line for the trailer’s service brake.
What happens when you push the brake button on a tractor?
The blue knobs will pop back out with no air in the tanks, or the yellow knob is out. If the yellow, and the blue knobs are depressed, the tractor spring brakes are released and the tractor can be driven. If you pull the yellow knob to set the spring parking brakes, the blue knob will also pop out.
Do you have to have yellow and blue brake valves?
To move the truck and trailer, you have to have BOTH the blue and yellow in…if you leave the blue out, and push only the yellow in (providing your trailer is hooked up, charged, and the red knob is in) you still will have the tractor brakes locked.
What’s the difference between red and yellow air brakes?
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..
Where is the blue brake valve on a tractor?
It usually had a green knob and was located to the far right of the air control valves. Blue was tractor only as stated before. We used the blue tractor only alot with our log trucks as you were “trailerless” half the time.