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

I think it’s Bendix 107216 for $19.

 

the tractor protection valve is not part of the dash valve/module, it is a separate valve usually mounted near the rear of the tractor cab

the TPV will shut off air supply to the trailer irregardless of what the dash valves are doing... i.e. - the red dash valve can be pushed in, and the trailer spring brakes could be applied because the tpv has blocked trailer supply air... the point being; the 2 operate independantly of each other

Hence the only button to come out would be the red trailer supply valve. You would want to apply the parking brakes while your driving on the tractor. Now the PP1 yellow valve should pop out when the air gets low because they want you to be able to stop..

 

yes both do pop out at the same time when hooked to a trailer BUT, when i just press in yellow and pump down, it doesnt pop out, I looked at DOT reg book and it doesnt actually give the specifics about what needs to happen actually, so im still confused????????

 

The inspection it’s a quarterly company inspection

 

I see, but they’re looking at the yellow one, and they have an issue because it doesn’t pop out . So technically I’m ok,

 

I have found someone having same issue like mine:


OK heres some background info.... i was DOT'ed in VA about 6months ago, i was shut down because DOT said i had a bad tractor protection valve, he had me push both brakes in with red airline unhooked and let air leak out, and the buttons were suppose to pop out, only the trailer brake did, so i had TA come out and give me new tractor protection valve and i was on my way............. i havent been DOT'ed since but the other day i went to test it and it still didnt work.(only trailer would pop out) I bought a rebuilt MV-3( i think thats what it is) and replaced the tractor valve and the seal... Now they both pop out, but when i press just the tractor brakes button pump down air, the button still doesnt pop out(although the buzzer does come on) my question is, is it suppose to???? and any suggestions on how to fix?

 

The way the company tested my truck is they pressed the yellow one only and then pressed the brake pedal to see if it’s popping out, and then they said it’s not popping out between 40-20psi. They didn’t touch the red one. It was bobtail so, no need, I guess

 

So this person replaced the tractor protection valve, then purchased a rebuild one , and it didn’t change anything.
I could spend $320 in parts just to see the same outcome .
I’m confused