Brake drum removal - what the Shop Manual doesn't tell me.

[DonaldSmith]

On a hard stop, my 47 DeSoto Suburban pulls hard to the left.  Not so with a gentle stop.  A few years ago, this happened briefly, but went away as I continued to drive the car.

Solutions:  1)  Drive the car more.  (Getting to be a pain.)   2) Inspect the brakes.  (A pain for sure.)

 

OK, how do I get the drums off to inspect the linings, cylinders, etc? Obvious?  The Manual doesn't say.  Years ago I inspected the front brakes.  I remember now.  Take wheel and tire off, remove cotter pin and big nut, slide off the hub and drum.  No big deal.   For the rear drums, the Manual mentions "Axle Shaft Nuts - 142(min)" ft. lbs. but doesn't show the hub that the drum and wheel connect to, nor mention removing the hub.  We're supposed to know how to do it.  

 

Suddenly it's coming back to me!  The Forum has revealed this for years.  To remove the back wheel hub and drum, I'll need the legendary giant, heavy-duty hub puller (or loosen the nut and drive around until something goes Bang!)

 

Which reminds me of when I was a kid and my dad was confronting something that needed fixing. I asked him, "You gonna fix it yourself, or have a man do it?"  Good question for me these days.

 

[1949 Wraith]

Loosen the rear axle nut while tire is on and in contact with the ground using breaker bar etc. Remove tire, leave axle nut on loosely then use your heavy duty puller ensuring all 3 legs are centered and tight.

[Loren]

The first thing is to get (or borrow) a real hub puller.

The Chinese eBay pullers aren't going to do the job.

A used puller is fine as long as it's a good one.

The better the hub puller the less work it is to use it. Use several types and you'll see what I mean.

Heft is the key.

Once you get a good one, taking the rear drums off is not the terror it is with a crumby one.

I think nothing of it any more.

ALWAYS put a cotter pin in the nut if the wheel is going to touch the ground. We have a way of forgetting to do that and then you'll be singing that old country & western tune: "You picked a fine time to leave me loose wheel!"

 

[TodFitch]

1 hour ago, Loren said:

. . . ALWAYS put a cotter pin in the nut if the wheel is going to touch the ground. We have a way of forgetting to do that and then you'll be singing that old country & western tune: "You picked a fine time to leave me loose wheel!"

Been there, done that. Not a pleasant thing to have happen. Definitely put a cotter pin in immediately upon putting the nut on, forgetting is too easy and the consequences could be pretty bad if you drive without it.

[dwest999]

Keith has some good videos on YouTube on brakes in case you need a refresher.  

 

 

[desoto1939]

Nice video:  I had an issue where the bleeder screw was leaking fluid. It was not from the bleeder hole inthe screw but with the fluid seeping out via the treads onthe bleeder screw.

 

On my 1939 Desoto they use a very different type bleeder crew that had a cap on the end of the bleeder screw.  These are hard to find. I had chnaged out my bleeder screw about 5-10 years ago and there never was any issue with leaking fluid. Had the car up on jack stand and noticed some fluid onthe back of the rim and a spot of fluid on the floor. Pulled the rim and the drum. No leakage from the single brake cylinder that has step down piston.  Looked at the back of the backing plate and then saw the issue with the bleeder screw.

 

Changes to another new screw and the same thing was happening.  Found a NOS brake syslinder that I had and put inthe original style bleeder screw and the weeping stopped.  Found a brake specialist in Michigan and he had the replacement bleede screw that had the correct taper to seat the screw. replaced the bleeder screw with the new replacement and the issue was solved.  Might have been that the taper on the bleeder screw was not fully making contact to seal the fluid.

 

So the small things can cause issues.

 

Rich Hartung

Desoto1939@aol.com

 

[Andydodge]

This is the type of brake drum puller I bought 50 yrs ago when I had the 40 Dodge Coupe.....this puller has never met a tapered axle that it didn't like, it was called a "Coxhead" wheel puller.........the centre bolt is 1.75" so its reasonably big.......lol..............andyd 

[DonaldSmith]

Shazam!  The other day, my car was pulling to the left as I braked, the harder I stopped, the worse it pulled.

This set off demons in my head, contemplating a dreaded brake job, hub puller and all that. 

But I remember this happened before, after I hadn't driven the car for a while.

So I drove the car through the neighborhood today, doing gentle stops and panic stops, and even riding the brakes.   

It stops real straight, now.   That just leaves a host of other gremlins on my to-do list.       

 

[James_Douglas]

Don, When time allows...

 

Take the car to a good shop and ask them to take the tire off, then have then pull the nut and pull the drum. You can then inspect the lining and have them LIGHTLY turn the drum if it has too many ruts. Just tell them that leaving a little bit is preferable to taking too much off.

 

The MOST Important. Have them use a lot of anti-size compound on the tapered axle shaft, the key and the inside of the hub-drum where is contacts the shaft. Then have them put it back on and torque the nut down and put in a NEW cotter pin.

 

What is hell is if you have a wheel cylinder start to leak and you cannot get the drum off at home. When I got my Suburban home the first month it took me three weeks to get the drum off and I have all the tools and torch. Doing the above will someday save your back side. The anti-size works great and the next time a drum has to come off it will come off even with a cheap puller.

 

James

[Sniper]

21 hours ago, DonaldSmith said:

Shazam!  The other day, my car was pulling to the left as I braked, the harder I stopped, the worse it pulled.

This set off demons in my head, contemplating a dreaded brake job, hub puller and all that. 

But I remember this happened before, after I hadn't driven the car for a while.

So I drove the car through the neighborhood today, doing gentle stops and panic stops, and even riding the brakes.   

It stops real straight, now.   That just leaves a host of other gremlins on my to-do list.       

 

 

My 51 does the same thing, even to the left like yours.  On my list to fix.

[bamfordsgarage]

Would anti-seize reduce the friction between axle and hub and put more stress on the key?

 

My main experience with tapered axles is on Model T Fords. Lots of worn axles, keys and hubs in that crowd, and these are often attributed to insufficient axle nut torque — and grease etc on the taper. 

[Sam Buchanan]

I thought proper attachment depended on the taper and drum being dry and clean.

[kencombs]

50 minutes ago, Sam Buchanan said:

I thought proper attachment depended on the taper and drum being dry and clean.

So says every manual I've seen since I started working on these things in 1960.  No lube of any kind on mine, ever.

 

edit:  actually not every  manual mentions it.  Some are silent on the subject, but those that do discuss it have forbidden lube in that spot.

Edited July 23, 2021 by kencombs

[Andydodge]

And I'd suggest that you purchase a 12" length of keyway material........its cheap and any decent engineering shop should stock it, and replace the key if it looks like its got some wear..........and a nice new split pin of the correct size.........and I've never used anti seize either as my Oz manuals state that the hub/brake drum should be assembled dry..............andyd

[Go Fleiter]

well, I drove 2 seasons with loosened nut on the left back brake drum- but no "bang..."

I had it one whole winter under my practice to give the puller a good whack every morning- no "bang"...

 

 

 

Than I lost patience and had the drum cut.

 

 

Mechanic put a kind of secret copper paste like stuff on the axle-

forbidden or not!

No problems since taking the drums off!

 

The only thing I hate more is changing the universal joint´s  boots- no way to warrant a unhurt bellow - less pressing out the trunnion pin...

 

Good Luck!

Go

 

Edited July 26, 2021 by Go Fleiter

[Sniper]

Never had an issue with trunnion boots.  Unless they are so old that the rubber has dried out and they would fail soon regardless.

[James_Douglas]

I have been using a high quality anti size compound for two decades on the 1947 Desoto and never had an issue. I used it decades ago on my high performance 1964 Chrysler 300-K's and never hand an issue.

 

I always carried an extra set of keys in the 300's given the HP on those.  I do replace any keys that show any signs of stress. Once should remember that back in the day anti-size compound was not common in auto repair and that may well be why it was not included in many manuals. Grease is NOT a good thing to use in such situations and that is probably why why a lot of manuals said to do it dry.

 

James

[Go Fleiter]

Where could I get those keys new?

Bernbaums doesn´t offer them.

Are they standardized or have I to search for a special size?

Thanks!

Greetings from Düsseldorf!

Go

Edited July 26, 2021 by Go Fleiter

[Sniper]

Pretty sure they are a standard size.  You can buy key stock in bulk and cut to length, as an example from Grainger

 

https://www.grainger.com/category/fasteners/key-stock/key-stock?categoryIndex=1

[Dodgeb4ya]

Don't use the typical low carbon key stock. 

IE flywheel shear keys...   pto keys etc.

Key stock comes in different grades of steel.

The factory keys are a very high strength steel.

Just some more info....

[kencombs]

I do a lot of work on small engines.  Most use a tapered crank and flywheel with a key similar to our axles and hubs   
 

B&S, Kohler, Kawasaki , Onan all specify dry install.  Many flywheels have been split at the keyway due to a slippery wedge (the crank) and aggressive tightening. The material there is cast iron but I still use caution not lube.