Hello! Need help please. The yellow knob is not popping out.

Im under the impression that the yellow button is supposed to pop out, found the yellow one to pop almost at 0 pressure.

 

This is what they teach in the school, and what ICBC (Insurance Corporation of British Columbia, they run the whole show up here) does at the Road Tests for class 1's.

With the truck shut off, and the lines still connected, pump the brakes down to where the RED dash valve (tractor protection supply valve) pops out. It must be no lower than 20 PSI and should be in the 20 to 45 range, although it can be higher.

Once the red dash valve has popped out (dynamited) you get out of the truck and break the red line (supply) and listen for leaks. With the red line still disconnected, you break the blue line (service) and then make a brake application. There should be no leak from either line. If there is, then your tractor protection valve is leaking and it will probably be an OTS (out of service).

There is NO requirement that your yellow dash valve has to dynamite when doing a tractor protection test.

There is NO requirement that your yellow dash valve has to pop out anytime, ever, for any reason. Even when they are brand new at the factory.

The guy who gave you the ticket and made you repair the truck did not know what he was talking about. As long as he was putting you out of service for the Yellow Dash valve. It might have been for something else. Maybe you had an air leak in the TPV.

Except that is the way they USE to do it. He obviously has not be taught the new regulations.

I know this to be true, as I got the info from a Commercial Vehicle Inspector who works for the Dept of Motor Vehicles in BC. All of our pretrips and courses have been designed with their help to make sure we teach the law, not what the law enforcers would like the law to be.

 

This is a comment found online

 

If you pump your brakes until both valves pop, that is NOT a tractor protector valve check, that is a low air pressure valve test and yes, both valves must pop to pass the inspection. This sets the tractor brakes in the event of a major air loss in the MAIN or PRIMARY system

If you take the red line off, push in both red and yellow valves, your red valve should pop out when the pressure in the secondary air system reaches 20-40 lbs. The Yellow should NOT pop out due to a line leaking on the trailer. Your Primary system should loose little if any pressure due to a broken trailer line.

 

I understand that some trucks have different setup maybe, but I’ll look into replacing the valve see how that goes .

 

But I’m not, in Canada.