55 Buick Brake Thoughts and Ruminations

[M1842]

I finally got my driver side front brake apart last night.  The drum measures 12.094" on heavily and deeply scored surfaces, that's a goner  So only one of the 4 original drums would have been useable after machining. I went ahead and bought replacements from either Bob's or CARS, can't remember now, its been a couple years. I tried buying used drums but no one would guarantee their drums were machinable.  Someone saying "Its got a lot of meat still" was not a confidence builder when the seller had a no returns policy.

 

I took the pins out of the brake cylinder and they are not identical, the depth of the cut where the shoe rides is different.  Is that normal?  They do seem to be the same overall length.  I measured the distance with the pins installed from the bottom of the slot on one pin to the bottom of the slot on the other pin.  Then when I put the pins in the new cylinder, I will measure again.  It seems to me that if the cups are longer than the old one, then the brake shoes will be held further out.  Potentially, keeping the new drum from fitting over the new shoes even with the adjuster at it's smallest setting.  I think this may explain the problem I am having on the other side. How hard is it to find pins with the proper dimensions?   I'm wondering if someone compensated for the oversized brake drum by adding longer pins?  Are there any specs on what the pins should measure up?

 

I bought one of those deals on eBay probably 4 years ago, 4 brake cylinders and 3 rubber brake hoses for $99.  I broke one of the rears and replaced it with one from Bob's that worked much better.  I am considering replacing the other 3 now.  Especially, if the slot to slot measurement comes up significantly higher than the original. 

 

Speaking of the originals, I used a 2.5 pound ball peen hammer and a long bolt as  drift and started working on driving the old cups out of the bore.  It is not going easily, to say the least!  My other thought is to have the old ones sleeved and then rebuild them.  That would eliminate issues with off shore made parts of dubious quality and dimensional compatibility.

 

Mark

 

 

[packick]

Mark:  I don't know if a picture will help you in determining the proper length of the wheel cylinder pins, but here is a picture of the right-front brake setup on my '55 Century:

 

 

[M1842]

Hey. Thanks for the photo if the passenger front brakes where the drum will not fit over the fully retracted shoes.   The interior of the drum measures 11.99 to 12.01 depending on where I measure the diameter. The shoes and hardware are all brand new, shoes match the curve of the drum.  The hold down pins are too long, there is no tension on the hold down springs.

 

Here is a picture of the brakes. Anything look incorrect?

 

 

[M1842]

I just thought of this, should I be putting brake fluid in to the brand new cylinders to ensure the seals and pistons can move freely in the bore?

[Gary_Ash]

Some replacement shoes have thicker linings, allegedly to compensate for worn drums, but that makes it harder to put new drums on.  Brake shoe machines got banned because of asbestos in the old linings, but now that the asbestos is no longer around, the shoe grinders are still banned.  Maybe a friend still has one in his garage...

 

You can use an electric palm sander with 36-60 grit paper to bevel the ends of the shoes.  That sometimes helps.  If you are brave, you can even go over the whole length of the shoe to take a little meat off.  You can also use some spray adhesive on a strip of coarse sandpaper, stick it inside the drum, and work the shoes against it to make the radius match.

 

Another way around the problem is to shorten the threaded portion of the adjuster and the sleeve that threads onto it.  Perhaps a 1/4 inch will let the bottom ends of the shoes come together enough to get the drum on.  Adjusters are cheap and replaceable. 

[Bloo]

5 hours ago, M1842 said:

My other thought is to have the old ones sleeved and then rebuild them.  That would eliminate issues with off shore made parts of dubious quality and dimensional compatibility

Good plan. Brake and Equipment of Minneapolis does a nice job of sleeving. There are quite a few others around too.

 

1 hour ago, M1842 said:

I just thought of this, should I be putting brake fluid in to the brand new cylinders to ensure the seals and pistons can move freely in the bore?

If you have them apart, use Sil-Glyde. Be sure to also get it on the part where the piston and bore are dry. Rebuild kits used to come with a little red capsule of clear goo for this purpose, but hardly ever do anymore.

 

3 hours ago, M1842 said:

Here is a picture of the brakes. Anything look incorrect?

 

 

Not really. Be absolutely sure the curved spots at the top of both shoes are tight against the anchor pin.

 

Edited September 20, 2022 by Bloo (see edit history)

[EmTee]

With all of these new parts, be sure to do the anchor pin adjustment as described in the 'major brake adjustment' section of the shop manual.  That will ensure that the shoes, as mounted on the backing plate, are centered in the drums.

 

I had the same holding pin issue with my '38 Century.  As a temporary fix I found some nuts that were the right thickness and put them under the head of the pin to shorten the working length.  Once I determined the proper length pin I was able to have my local NAPA order them for me.  They can look them up by length.

 

Edited September 20, 2022 by EmTee
typo (see edit history)

[KAD36]

2 hours ago, Gary_Ash said:

You can also use some spray adhesive on a strip of coarse sandpaper, stick it inside the drum, and work the shoes against it to make the radius match.

^-   X2.  Take your time until the pattern is uniform. Slight bevel to the edge and gtg.

[M1842]

2 hours ago, EmTee said:

With all of these new parts, be sure to do the anchor pin adjustment as described in the 'major brake adjustment' section of the shop manual.  That will ensure that the shoes, as mounted on the backing plate, are centered in the drums.

 

I had the same holding pin issue with my '38 Century.  As a temporary fix I found some nuts that were the right thickness and put them under the head of the pin to shorten the working length.  Once I determined the proper length pin I was able to have my local NAPA order them for me.  They can look them up by length.

 

I did this on the rears.  I will be sure to do the fronts as well.

[M1842]

"If you have them apart, use Sil-Glyde. Be sure to also get it on the part where the piston and bore are dry. Rebuild kits used to come with a little red capsule of clear goo for this purpose, but hardly ever do anymore."

 

This jogged my memory, when I did the brakes on my 51 Chevy 30 years ago, the new cylinders came with that clear goo stuff. I had completely forgotten about it.

 

[M1842]

I beveled the ends of the shoe lining and shortened the adjuster by about a 10th of an inch.  The drum went on further than it ever has but still stops short and is bound up by the shoes.  Tomorrow I will shorten the adjuster again.

 

The curved tops of the shoes are right up against the anchor pin.

 

Nice to be making some progress again!

[M1842]

Took another 10th of an inch off the adjuster and the drum went all the way on but does not turn.  I think I will leave it for now til I get the anchor pin loose and can do the adjustment.  Then see if the drum turns 

[EmTee]

Start by just loosening the anchor pin.  Tap it with a brass hammer to make sure it's free from the backing plate and see whether the drum will turn.

[M1842]

That is my next step. Applying penetrating oil to the threads of the anchor pin. So far, I can't get the  nut in the anchor pin to break lose.  The pin is right in front of the steering knuckle so I can't put a socket on a breaker bar. I bought a 6pt 15/16 wrench, I am looking for a pipe I can use to extend it.

 

Update: found it was cheaper to buy a wrench extender than buy a piece of pipe to go over the end of the wrench.

Edited September 26, 2022 by M1842 (see edit history)

[EmTee]

22 hours ago, M1842 said:

So far, I can't get the  nut in the anchor pin to break lose.

Probably means it's been awhile since the last adjustment was performed... 

[M1842]

I finally got the anchor pin out of the backing plate.  I ended up using my new wrench extender and a 24" breaker bar, along with some heat and penetrating fluid.  It broke free and I got the nut off.  Had to use a hammer to break the pin free from the backing plate.  The rear brakes were not nearly as bad as this!  On the rears, once I had the nut loosened I could move the pin up and down.

 

Must be decades since the last brake adjustment! 

 

 

Mark

[M1842]

I cleaned up all the parts of the anchor pin this afternoon and reinstalled on the back plate which had also been cleaned around the anchor pin hole.  Reattached the brake springs and put the drum on.  Low and behold, it went on easily and spun without effort.   I am in business now, will be able to adjust the shoes and move onto the other side.

 

I will go ahead and remove the other anchor for cleaning before I do anything else on that side. I never thought that could be a problem.

 

I feel like this has been the world's longest brake job at 3 years but this feels like a break through (pun intended).  I still have to put the rebuilt master cylinder in and the new steel lines.  

 

I have had to do a lot of side jobs along the way like rebuilding the parking brake and replacing a control arm.  I am hopeful that I am done with surprises on this task.

 

I am retiring next week and plan to spend more time on the Buick.  Work has put a crimp in my hobby time. 

 

Mark