Drum In Hat Parking Brakes part of Disc Brakes on Automoble

[MEASURE TWICE]

I have checked with repair shop for the slight roll before grabbing to stop the vehicle on a Manual Transmission truck and they said it is normal. Drum In Hat (DIH) is the small drum brake inside the Rear Wheel Disk Brakes. This mechanic checked it and said it is different that my prior truck which did not have 4 Wheel Discs (w/DIH). The same model truck in the past had Disks in front and Drums in rear, so that is why this happens. Thinking maybe not so fast. I have found many having this same thing happening and have not had answer with specifics why it happens. I sure would like to know as I think it is @%^#$.

Depending on grade of slope when parking it can be 1 to 3 inches of roll before it grabs. Not very comforting. The amount of hold once it grabs is just great once it goes any where from 0 to 3 inch of rolling. The parking brake pedal only needs normal pressure and goes just half way the travel to the floor, so that is good. Looked at the cables and they are fine.

In neutral with the parking brake set and the engine off on level ground I am to get some chalk to mark where the wheels are when vehicle is pushed and expect to see this play. Forward to Aft roll measurement is what I want to know. Then when I know exactly the amount I can check with manufacturer rather than the place that did my brakes about a year ago and find out what is said.

Anyone come across this and have any way to fix if in fact it is not normal?

PS

I always put in reverse (lowest gear) when parking along with the manual shift DIH Parking Drum Brake Brake.

 

[Greg58]

My Chevy 2500hd does the same thing, however it is a automatic. If you've ever had it apart the little shoes seem to small for the job to me.

 

[MEASURE TWICE]

My Chevy 2500hd does the same thing, however it is a automatic. If you've ever had it apart the little shoes seem to small for the job to me.

Thanks:
I did not see them but only from the outside you see the circumference diameter of the drum which lets you know. OK, I guess I have been more recently parking a greater amount on non-level ground and just noticed.

Only if the rolling can become greater in distance due to something wrong I would then worry about it.

Still wonder mechanically how it does this when compared to the regular size rear drum brake?

What I mean is I don't think the brake should when making contact with the drum allow for rolling, then subsequently grab and hold perfect. So that I think only leaves it that the shoes are held sort of in a flimsy manner and are allowed some free play in either.

I saw some online pictures showing the parts but not clear enough to see what I would then try to compare to a regular drum brake and know precisely what is in my book really not quite right.

A recall for cable coming off when in icy conditions was done on the parking brake on my vehicle, but that I can now know had nothing to do with this slight roll issue. Also the brake jobs done at shops also had nothing done wrong either.

I do have a wedge of wood I put under a wheel to chock when on really steep hills, as well as the parking brake and the tranny.

 

[Greg58]

The block of wood works every time, I keep plenty of fire wood so a lot of things get scotched with a wedge around here.