Jump to content

Brake drum max inside diameter??


Worden18

Recommended Posts

Hey guys,

 

I've been working on my '51 Meadowbrook rear brakes.  I'm sure a lot of you have seen my recent posts in "Me and the Meadowbrook", but I wanted to start this separate topic so it reaches more people in case some folks are not following my thread.

 

NOWHERE in my shop manual does it say what the max inside diameter of the rear drums can be.  Does anyone know this dimension?  Could it be actually stamped on the drum itself?  I'll admit I haven't taken a close look at the drums yet even though I got them off.  I'll likely have to use a wire brush on them in order to read any numbers if they indeed are on there.  I know this knowledge is like squeezing toothpaste out of a tube for some of you guys, which is exactly why I am asking.  Help me out if you can.  Thanks!

 

John M. 

Link to comment
Share on other sites

5 minutes ago, Worden18 said:

Hey guys,

 

I've been working on my '51 Meadowbrook rear brakes.  I'm sure a lot of you have seen my recent posts in "Me and the Meadowbrook", but I wanted to start this separate topic so it reaches more people in case some folks are not following my thread.

 

NOWHERE in my shop manual does it say what the max inside diameter of the rear drums can be.  Does anyone know this dimension?  Could it be actually stamped on the drum itself?  I'll admit I haven't taken a close look at the drums yet even though I got them off.  I'll likely have to use a wire brush on them in order to read any numbers if they indeed are on there.  I know this knowledge is like squeezing toothpaste out of a tube for some of you guys, which is exactly why I am asking.  Help me out if you can.  Thanks!

 

John M

Generally .060 over 10 or 11 inch drums max.

What do they measure now?

Edited by 55 Fargo Spitfire
Link to comment
Share on other sites

2 minutes ago, 55 Fargo Spitfire said:

Generally .060 over 10 or 11 inch drums max.

What do they measure now?

I haven't measured them yet.  I only have a 6 inch caliper, but a friend of mine has a 12 inch, or I can use my boss' caliper at work.  Not sure if there would be another more accurate way to measure other than with a caliper.  I can't imagine getting close at all with a tape.

Link to comment
Share on other sites

1 minute ago, 55 Fargo Spitfire said:

Are they in good shape now?

If they need machining take off the least necessary.

When I pulled them off earlier today I just gave them a quick once-over.  They did look in good shape.  If they need to be turned, I can skim them at work.  I'll take them into work on Monday and measure them accurately at different points all the way around.  Thanks for responding.  I'll let you know how they "turn" out.  :D

  • Like 1
Link to comment
Share on other sites

10 minutes ago, keithb7 said:

I checked 3 different Mopar manuals that I have from the era. Nothing mentioned about drum max wear limit in any of them.

No they dont necessarily.

But most manufacturers and  jurisdictions limit passenger car brake drums to .060 over size and some to .090 stamped on drums at times too.

I would keep it to .060 on these to be honest as to not have any issues with the shoes expansion limits are not too far exceeded.

 

  • Like 1
Link to comment
Share on other sites

2 hours ago, keithb7 said:

How’s the job progressing Worden? Any updates? 

Been too busy the last couple of days to get at it; but, I'm going to take the drums to work tomorrow so I can get the right caliper to take a measurement.  That's step one anyway :)

They are 11 in. drums btw...

Edited by Worden18
Link to comment
Share on other sites

On 3/17/2018 at 7:13 PM, 55 Fargo Spitfire said:

Generally .060 over 10 or 11 inch drums max.

What do they measure now?

 

 

  I measured both drums today with a 12 inch caliper.  All around the surfaces of both drums they measured within a couple of thousands of an inch to the 11 inch diameter.  There is NO ridge at the bottom of either drum, telling me that the shoes did NOT wear out the drums in the least bit.   There's no wear or ridges or anything at all.  The drums are very true as well.  I won't have to turn or even skim them; the car has no shimmy at all when braking.

 

  Since cars like this hardly ever have their brakes jammed on hard consistently (you don't go fast, you don't stop fast....at least that's how I drive) I can totally understand how these drums  have zero wear on them.    

 

If the drums had measured .005 - .060 oversize, making them 11.060 max diameter, then for sure there would've been some wear I  would have detected:,  a visible ridge at the bottom of the drum where the shoes don't touch; no doubt a guy could've felt even .005 with a fingernail.   

 

So, I have to get busy and clean up the drums and start making some progress.  This weekend looks promising. :)

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use