Rear brakes are giving me fits.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
2,029
Reaction score
2,935
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
This should be relatively easy to diagnose. If the old drums were dragging that's a clue. Go back to basics. Make sure the shoes are retracted onto the anchor pins and emergency brake cable is free. Then if residual pressure is suspected open a bleeder. Like I said in the first post, incorrect shoe size will be obvious if they are placed in a drum. They should have a very similar [not exact] diameter.

Match up the remaining parts. Make sure it is assembled correctly, primary and secondary shoes are in the proper location.

I have seen shoes that had too much material for the application, may be a couple times in 30 years. Do the basics first, then the odd problems.
 

rusted nuts

Full Access Member
Joined
Mar 5, 2023
Posts
809
Reaction score
1,421
Location
Pa.
First Name
Jeffrey
Truck Year
1979
Truck Model
k20
Engine Size
4cly diesel
Where is the RPO typically located? I want to say I saw something inside the glove box door? I'll have to double check.

Rusted Nuts & Fast 99: No the drum would not turn by hand before I removed it. In fact it was so tight the shoes and hardware came off with the drum. That's when I found out the adjuster was backed all the way off already.

Rusted Nuts: There was no ridge worn in the drums. That's the part that's truly puzzling. It's like they were brand new just installed with no wear at all, yet they were installed that tight and I drove the truck from Ft. Wayne IN to Grand Rapids, MI with no issues.

Even when I removed emergency brake tension completely (to swap a frayed cable) I still couldn't get the drums to go back on. The one thing I haven't tried yet is the cylinders. I'm wondering if maybe I have the wrong ones, as I did replace those. Last night I did confirm that my drums are exactly 11".

The next time it's not raining or snowing here (or both in the same day) I'm going to dig into this thing again. I'll let you guys know what I find. Stay tuned lol.
I have had rubber brake hose cause this They were breaking apart inside and a bit of rubber would block the hose and not allow the brake to release.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,449
Reaction score
8,686
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
I have had wheel cylinders stick in their bores. I know someone already mentioned that but be sure to check it.
 

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
2,029
Reaction score
2,935
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
Opening bleeder would eliminate a failed brake hose, if shoes were on anchor pin that would eliminate a wheel cylinder. Yes, either could cause the described problem. There are ways to narrow it down.
 

Brownsquare

Junior Member
Joined
Jul 4, 2021
Posts
19
Reaction score
6
Location
Wayland, Michigan
First Name
Marc
Truck Year
1987
Truck Model
R1500
Engine Size
4.3 V6
UPDATE (although not much of one): I took both sides apart again and opened the bleeder on both cylinders. They won't compress any more than they already are, so I don't think that's my issue. Right now I'm half through replacing the emergency brake cable...wondering if that might have been too tight. I'll keep you guys informed. -Marc.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,853
Reaction score
5,646
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,76,70,48
Truck Model
Suburban k10, bonanza k10, k30, k20, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350, 350
UPDATE (although not much of one): I took both sides apart again and opened the bleeder on both cylinders. They won't compress any more than they already are, so I don't think that's my issue. Right now I'm half through replacing the emergency brake cable...wondering if that might have been too tight. I'll keep you guys informed. -Marc.
I'm telling you guys.

I tried multiple new rear drums. They aren't cut right or the shoes are too big. I had to get my drums cut, to fix my brake drag problem.
 

Latest posts

Forum statistics

Threads
44,163
Posts
950,654
Members
36,276
Latest member
2manysquares2care
Top