Self Adjusting Brakes on a 56 http://forums.aaca.org/topic/281516-self-adjusting-brakes-on-a-56-buick/Buick

[Beemon]

Just a tech thread as I've just finished doing the swap today. Theoretically you can do this with any 12" Buick drum, but I have not seen anything smaller than 2" shoes. That being said, the 2 1/4" shoes on the 56 goes well above 1968, which is where I pulled the donor equipment from. I only pulled rear equipment off two cars because they did the front adjusters differently than the rears (and all the fronts were missing anyways), but the rears on the 56 are set up the same as the front minus the parking brake.

 

Parts used:

NAPA #UP2340 - spring kit readily available

NAPA #UP80551 - left side adjuster

NAPA #UP80552 - right side adjuster

NAPA #UP80762 - adjuster return spring

 

The adjuster arm, steel rod and override arm/spring were re-used from the donor cars as I could not find the part numbers and will be checking known vendors for replacements soon. Still have yet to pull the front drums off as the store didn't have a second spring kit on the shelf, but tomorrow I'll be picking up and pulling the fronts. With only the rears being self adjusted though, I noticed an immediate difference in braking and parking brake function due to the minuscule adjustments these systems accomplish.

 

It really is unfortunate the actual hardware part is not made aftermarket like the 9" Chevy self adjusters. When classes begin on the 19th of September, I was going to stop in the manufacturing department and see what it would take to have replicas made. I don't know if there's a huge demand for it for the pre 1960 Buicks, but the system was obviously very successful to be used for over 10 years until the advent of disc brakes. Needless to say, these 68 Rivieras will live on partially in my 56 Riviera.

 

[JohnD1956]

Interesting idea.  I had never considered this. 

[old-tank]

When using auto adjusters you need a brake drum caliper (https://www.amazon.com/AMPRO-T71558-Brake-Resetting-Gauge/dp/B00A8FOEFE/ref=sr_1_1?ie=UTF8&qid=1472228668&sr=8-1&keywords=drum+brake+gauge) to set the shoes.  When installing new shoes this may need to be done a few times every 300 miles until stable and will need to be checked if erratic braking.  After that the auto adjusters will keep the adjustment for the life of the shoes and you can avoid adjusting every 6,000 miles.

Good research and work...I really like you you keep thinking of new ways to do things!

Willie

[Beemon]

A lot of the stuff I do is overly ambitious lol ... at least I know this one will work and be reliable for the life of the vehicle. 

 

Is it every 6000 miles? I was told to check them every 1000 miles. It's not that I don't like adjusting the shoes by hand (even though it is), every time I crawl under there I spend more time than I want to because I either go too far or loose track because the tool slips and have to start all over again. The rears aren't an issue but the fronts are right under the king pins and are just more trouble. 

 

Also thanks for the link to the calipers. I admit I didn't know such a tool was needed. Before I get too far I'll be sure to check out the shoes again. How I had assembled it was I tightened the adjuster by hand until the drum couldn't slide over the shoes, then loosened it until it wasn't a tight fit but with slight drag. My plan was to see how well it performs for about 100 miles before peeking in there again. 

 

It's too bad I could never get the aluminum drums on there. With the modern hubs, it needs to be spaced about a half inch off the back of the spindle and then a quarter inch needs to be shaved from the tips of the backing plates (maybe more) for a snug fit. If/when I buy new front drums, I'll test fit them with the roller hubs. 

Edited August 26, 2016 by Beemon (see edit history)

[Beemon]

Self adjusting brakes Part 2:

 

 

I forgot to mention, the nails in the spring kits are marked "8" but the originals are marked "4". The 8 is also smaller than the 4, which makes sense because the rears on the donor cars were only 2" pads and not 2 1/4" pads. Part #UP80707, I'll update the OP with this number, too.

 

 

With more than enough room on the front wheel hubs for the adjuster. When I pulled the original manual adjuster off, I dialed in the auto adjuster to about the same length before re-assembly. I also forgot to take a pic of lubricating the rear backing plates, but I just sprayed some white lithium grease on the pressure points to avoid squeaks. I picked up a caliper like the one Willie posted and it was pretty close, only a minor adjustment to get it where it needed to be. Buttoned everything back up, backed out of the driveway somewhat aggressively and nailed the brakes... pretty interesting experience when you can feel them do the fine adjustments! I did a couple of quick reverse stops on the neighborhood drive just to make sure they were seated in and then went for a drive.

 

Pedal response was faster and the pedal was higher as it didn't take as much to get the brakes to energize when finely tuned. Overall though, besides the higher pedal, there was obviously no difference in braking. I was able to put more pressure on the brakes because of the higher pedal, but that was the only difference I really noticed. Ease of application and not having to worry about adjustments in the long term was the ultimate goal from the beginning. Measures should be taken to check the pads bi-anually, or sooner depending on pad life.

[NTX5467]

The faster response can possibly end up with less distance travelled, even with the same deceleration rate . . . which is good.  The added confidence of the higher pedal apply position can also help with the confidence that the vehicle will stop sooner.

 

Used to be that a brake adjustment "touch-up" was done about every 2nd oil change, back then? 

 

Even with automatic adjusters, that initial adjustment is critical to the correct operating and response of the system.  That's why that adjustment caliper is so neat!  Worse thing is that you have to pull the wheel and brake drum to use it, but it can be worth the extra effort rather than developing "the feel" of using the brake adj spoon and a thin-shaft screwdriver.  THEN hoping you don't destroy the adj hole plug in the process!

 

Keep us posted on how things continue!

 

NTX5467