Help identify air system part

[Lead_sled]

What’s the name of the valve at the front of the tractor that splits and supplies air to the front brakes?

When I press my brakes, air is escaping at this valve/splitter and at the brake foot valve.

[Nilao]

You mean the treadle valve on the firewall with like 8 lines coming off it?

[RocketScott]

Not too up on all the newer trucks and ABS systems but...

It's probably just a quick release valve. QR-1

My truck has an LQ-2 that acts as a limiting valve too. There's an air switch on the dash labeled slippery or dry road. I don't think many trucks use those anymore

[Chamberpains]

If you have air puking out the quick release valve, go ahead and change it. They are cheap and often forgot about. They get gummed up. But that may not be your problem check all you brake chambers for leaking internally. Have some one hold down your brake pedal down and have a listen to all of them.

[JimT]

(04-01-2021 )Lead_sled Wrote:  What’s the name of the valve at the front of the tractor that splits and supplies air to the front brakes?

When I press my brakes, air is escaping at this valve/splitter and at the brake foot valve.

I'm bad with part names too. Can you pinpoint the location? Maybe a picture would go a long way. Inside cab? Under cab? Inside engine compartment? If you have one of those radar braking systems there's probably more valve up front under/behind the bumper too.

[Lead_sled]

Sorry late on the reply, but here are pics of it. One from top and another from bottom. It has 3 lines connected to it. One line each side and another on top.

Been chasing air leaks since this was found.

[Lead_sled]

Looks to be this QR1 valve

[Lead_sled]

What’s the purpose of this valve? This guy is bleeding off air when I press the brake. But simultaneously bleeding air off at the foot valve. I have the foot valve in hand already to be changed, but someone told me to change this QR1 valve first because it may be the culprit of the foot valve bleeding off air.

[marek4792]

So there's a smaller air hose from the foot valve that sends an open signal to that valve there which opens a bigger valve that applies/releases the brakes. there is one for each braking system Spring and Service brakes respectively. the diaphragm inside is probably bad and that's why it is leaking air.