[Chas Stricker]

Howdy All,
I've noticed that it now takes more gauge pressure (7+ bar as opposed to 6bar) for the parking brake to fully release. It used to move immediately at 6 bar and now at the higher pressure one side drags a little. I don't hear air leaking. Any ideas? Thanks,
Chas

 

[Chas Stricker]

It can be parked for a few hours or day. It has been a gradual thing I think. I'm curious where to start. Could it be the "unloader" or a bad bag on the rear brakes or something blocking the lines? Could it be a leak, even though I don't hear a hiss? I'm trying to get an idea if you all have had a similar issue and I'll tear into it from there. I've had the truck about 5 years now and it would fully release the parking brake at 6 bar or less. I used to have to be careful because the 4-5 air shifter has always needed about 7 bar to work and it wouldn't shift. Now my "hold-up" is the parking or rear brakes.
Chas

 

[Chas Stricker]

I'm going to remove and clean the Gizmo that is squarish and has 4 large air lines going to it (I'm very technical). Ben and Bob have been giving me ideas and I'll go that way. I was to do it Saturday but I went and pulled a wrecker out of the mud instead. I hope to do it this week. I'll post what I find.
Chas

 

[Chas Stricker]

Howdy All,
I took the "Four-Circuit Protection Valve" apart today to see if it was gummy. Earlier I called it the Square Gizmo thingy. It had some nasties and the pressure adjustment screws needed heat and lube to become adjustable again. I totally messed-up all the adjustments, lubed it and put it back together. Still have the same problem. I'm attaching some pictures so folks will know what the part looks like. In the pictures I've already loosened the bolts and the top is raising up against the springs. On the good side......I now know what this part looks like inside but it would be nice if I knew what port fed what.

I wonder what a bad Parking Brake acts like? I noticed a valve after the PB and wonder if it is in there. Once again, any ideas.
Thanks,
Chas

 

[Chas Stricker]

Howdy Yarr,
I had a couple of issues. One was the 4-way control valve. The other was the rear parking brake portion of the calipers. Mine would take more pressure but the light would go off like it should. You might be having a different issue if the light isn't going off yet the pressure is beyond the typical point.
Let us know,
Chas