I call it this because it is making me very mad. I have spent way too many hours trying to understand how it should work and getting it to work properly.

It does not have the "wedge" between the pawl and sector gear.

You may recall from other threads that my parking brake wasn't working well. When I had the drums off for replacement I found and fixed the reason why. I took photos and will do a post on this, time permitting. Basically, there were burrs and sharp edges that prevented the parking brake applicator from moving full travel.

Now the auto adjuster is not doing its job. The best that I can get is about one inch above the floor where I am essentially pushing with my toes. Here it holds better than before my repairs inside the drum. Other times the pedal goes all the way to the floor. If I could get it tight about 1/2 to 3/4 way down I know the parking brake will hold very well.

Here is what is going on. I put a punch mark on the part that holds the pawl and another one adjacent to it on the part that has the sector gear so I could see relative movement between the two parts.

Upon applying then releasing, the punch marks move showing tightening of the cable by one tooth where the pedal goes to one inch above. The next application and release the punch marks show loosening by two teeth where the pedal goes to the floor. The next application, release the punch marks are adjacent again. When it is at one inch there are 5 or 6 teeth on the sector gear that could be used to make it tighter. Note that before repairs inside the drum the pawl was in the third slot of there the sector gear.

All the manuals say is that the adjustment is automatic and no service is necessary.

Signed, At Wits End.

 

After posting I looked at the mechanism some more and got an idea. I pushed the PB pedal as far as it would go. Went under the truck with a rope looped it around the cable splitter and tied it off forward. This left a lot of slack in the cable forward of the splitter. I released the pedal and the pawl ended in the third valley from the end. I pressed the pedal and it got very firm and stopped about 3 inches from the floor. I tested the holding power by applying throttle. It was about 1600 RPM before it started to move. Before it would begin to move just above idle.

Success? Kinda. With the rope removed and the pedal released the auto adjust put it back to where it was in my original post. I know that they have those wedges that prevent the pawl from disengaging the sector gear and the auto adjust from working. I could get one of those, but it would be nice if it worked right.

 

The first thing to do when troubleshooting any problems with the parking brake is to manually adjust the rear brakes. Have you done this?

 

I just installed new brake drums and adjusted it until there was a slight drag. I pulled the axles so I could get a good feel.

 

Good news is that with my modifications to the brake shoes and new drums the parking brake will hold up to and at stall speed (just under 2000 RPM). Much better than the 1000 RPM that I started with.

Have you tested your parking brake this way? What were the results?

Bad news is the automatic parking brake adjuster failed and created enough drag to heat the brake drum to a deep purple (about 550 deg F). The drums are thoroughly warped.

I hope the shoes are OK. Any opinions on this?

Good news is I didn't like the Centric drums because they don't have the proper groove at the outer edge to form a labyrinth seal with the backing plate and this won't keep the water out like it should. I bought NOS Ford, made in the USA, drums on eBay for about the same price as the crappy made in China drums. I can't wait for them to get here. First delivery estimate was Friday, then today, now they are guessing Tuesday.

 

Did you buy a used axle? If so perhaps it's got the wrong brake parts in it.

 

Nope, original axle as far as I can tell.