Issues after brake valve replacement

If its not a nicked plunger I’m wondering if having full pressure, which i didn't before, damaged an already disintegrated rubber inside the rear valve? I’m going to replace that assembly next. It’s also original. Was going to do all the valves but this one is pricey.

 

I was wondering. Mine was rusted and almost seized anyways. I went ahead and ordered a new one. I do actually have good working brakes now. I thought I had a proportioning valve and that was giving issues but it was the plunger all along…..and possibly valve. Next week everything will be new and good to go.

Thanks to everyone who replied. It helps in learning this truck and these systems. Didn’t really care as a company driver and I wish had.

 

Interesting. I just looked at a pic I took and the rod is threaded and there is a nut on it. Will check when I get home tomorrow. Thank you!

 

Update: I installed a new plunger and housing. I may have dinged the other one up when I dropped it 3 times, making it stick and thus having slight brake application. I also adjusted the rod just in case. All seems to be fine now. Thanks again for all help and suggestions.