Its a Volvo Problem

[RyanC]

This might help with some of this
http://www.wabco-na.com/literature/Air-B...rol-Valves

Saved me a few times. Find which ever valves you have and do the tests.

Hope this helps.

[Evotrucker]

(04-22-2019 )Nilao Wrote:  From what i see in your picture the red line comes from the trailer brake release valve in the dash. Should only have air supplied to it with the red knob pressed in. The green line should be a supply from the foot valve, always pressurized. The grey line comes from the treadle valve on the dash and the orange line comes from the application port on the foot valve. If you were to remove all from that valve except the green line there should be no air escaping from those lines, with the engine running you will still be able to feel air escaping even without the tanks being at full pressure...if you unhook all those lines and the valve is still venting then its the valve.

Your colors may vary so look and see what lines come from the components of your truck...ie some truck use a orange line from the brake valve release on the truck

I actually replaced the tractor protection valve already twice, I thought it was faulty the first time around. When I put in the new one, made no difference.

[Evotrucker]

(04-22-2019 )RyanC Wrote:  This might help with some of this
http://www.wabco-na.com/literature/Air-B...rol-Valves

Saved me a few times. Find which ever valves you have and do the tests.

Hope this helps.

Number 14 is a relay valve, it says if service brakes applied the relay valve is not seating properly so gotta replace it... so I got a tech from a local shop here to come out here n see what he can do.

[RyanC]

I think this is getting over thought.... the hose that's leaking is stopping your truck from building any air. Follow the hose that's leaking to the next valve or component it plugs in to. Disconnect all lines from it to find which one air is coming from. Do the tests and see if air is supposed to flow that component under your conditions. If it is supposed to flow then follow to the next component and repeat.

Opening loom sucks and in winding the birds nest of bullshit is worse.... but sometimes you gotta go caveman style and just follow it along.

[snailexpress]

This yellow tube is exhaust from park control dash valve. From valve it's going thru manifold outside.

https://www.youtube.com/watch?v=-1vA1EnNJZ4

[Magard]

Edit post. Ok so I do have that yellow line. It only exhausts when setting trailer brakes. If that helps at all.

[Evotrucker]

Small update, towed the truck to a volvo dealership.

I'm sure they will figure out exactly and let me know in a couple of days.

[Evotrucker]

got the truck back today, turned out to be a bad in dash relay.