Issues after brake valve replacement

1998 FLD120. Just replaced the Bendix E6 brake valve. Brake lights come on and the rear brake valve will start purging and the rear front axle brakes will cycle on and off. The truck is off when this is happening and you can hear the air moving through the system.

Maybe the plunger that the brake pedal rod pushes out to actuate the brake valve is sticking? Seems if I push pedal in and out it stops and lights got out.

 

Truck off, air is leaking out of the exhaust on rear valve. No brake lights yet.

 

Is that the plunger that is on the firewall that connects to brake pedal.
Mine would always get stuck due to rust from water getting in.
Need to sand it an put some antiseize an silicone where it attaches to the firewall.
That is the entrance of water

 

Yes. I sanded off the corrosion and lubed it. Also used gasket maker to form a gasket since I didn’t have a replacement.

 

The plunger should move snuggly back an forth when u apply pressure from the pedal.
After that your lights should turn off an not lose pressure.

 

I feel like its still sticking now but maybe not enough to activate light. Right now lights are off bit the air is moving and releasing/leaking from rear valve.

Wonder what the chances are that rear valve decided to give up the same time I’m replacing another one? That would be my luck. Im trying to get this fixed as I have a load to pick up in 4 hours.

 

@Rideandrepair @xestra

Any ideas?

 

I don’t know much about it at all. Maybe go through the cycles, test drive it a bit if possible, maybe try hooking it to a trailer. Release brakes, see what happens. I’m wondering if it’s just in bobtail mode. Brake valves operating at less force? I really don’t know why it would be exhausting. Maybe pump them down while running with parking brakes released. Let it build up, and see if it starts working right? My treadle valve was sticking in very cold weather. A good hard jab on the pedal would release them. The brake lights supposed to come on at 5lbs application.

 

Ok. Good to know about the lights as i was always curious. I do think it is the plunger sticking. Maybe it got nicked and is getting hung up. I dunno. I cycled the ABS system hoping it was dirt or debris somewhere. I also pinched off brake hoses to see if a can was bad and was cycling back through (mechanic on YouTube did this)

Im going to run with it. I have a short run out and back so if i have trouble I will always be near a shop.

 

If you ever need to change an air brake switch. One of the 2 on parking brake. Hopefully you can read NC65 or NO5 on either. At least NO or NC will identify which one it is. From my notes.