39-48 brakes question

a banger

a banger

Member
Hey fellas , I've got a question about brakes. It's my understanding 39-42 brakes have adjustable anchor pins, while 46-48 have self- centering non-adjustable pins. Any pro's or con's to one or the other? Also what drums can interchange from one backing plate to another? I'm planning on running 35 wire wheels and would like to run 35 drums with hydraulic brakes. Any ideas ? Thank's

 
You're right on the backing plates, but as far as I know, the 35 drums will not be compatible.
You will need 40-48 drums, with a spacer ring around the center hole of the wheel about 3/16" thick.
You might have to remove some balance weights from the drum to allow the wheel to seat.

Mart.
 
'35 rear drum/hubs will work with the later hydraulic brakes. You would have to run the original '40-'48 drum/hubs or the repro MT USA made drum/hubs on the front. You would need the proper spacers on the front using these drums w/'35 wires but no spacers would be required on the back if you use stock '35 rear drums. This is how one of my cars is setup now.
 
a banger said:
Hey fellas , I've got a question about brakes. It's my understanding 39-42 brakes have adjustable anchor pins, while 46-48 have self- centering non-adjustable pins. Any pro's or con's to one or the other? Also what drums can interchange from one backing plate to another? I'm planning on running 35 wire wheels and would like to run 35 drums with hydraulic brakes. Any ideas ? Thank's
Click to expand...

You are correct about the 39-42 vs. 46-48 brakes. The 39-42's require adjustment of the anchors ONLY when new linings are installed (to center the linings in the drums) and after that, only the upper "clearance" adjustment is required to compensate for wear. While the 39-42's require that extra adjustment, which is easy when you know how and why, once that is done, the adjustment becomes the same as 46-48.

Some feel that the 39-42's are more precise and that there is some kind of nanosecond delay when the 46-48 brakes are applied, while the shoes find center, but I doubt if anyone would really notice the difference. Accordingly, subject to the above, they are equally good... but NOT as good as Lincoln-Bendix Self ENERGIZING brakes.

Regarding the hubs/drums, the 1935 fronts are offset about 1" inward on the hub as compared to 40-48 hubs/drums, and therefore will not fit with hydraulic brakes EXCEPT for 39-40 Lincoln Bendix "deep fronts" on 32-34, 35 or 36 spindles with some extra work involved and special kingpins/bearings etc. Otherwise, when converting a 35 to hydraulic brakes, it is necessary to use 40-48 front hubs/drums, along with a pair of Wire Wheel Support Rings of the appropriate style depending on which exact hubs/drums are being used. The 35 rear hubs/drums can be used as they are for hydraulic brakes IF they have not been machined beyond the limit (my practice is 12.060" diameter maximum) for which there seem to be differing opinions...
 
Mart and JM 35 Sedan: Your posts were not there when I STARTED writing mine. JM is correct about the 35 REAR hubs/drums being compatible... The offending balance weights on 40-48 hubs/drums are usually only an issue on the "inside drum, outside hub flange" style. The "outside drum, inside hub" style works much better with wire wheels for this and other reasons...
 
Hey guys, thanks for the tips on the drums. I have both types of brakes in my collection of parts, so i should be able to make something work. I was thinking the later plates with the self centering pins may be a plus,less of a hassel to adjust, but i'm not sure. any thoughts on that ?
 
The initial adjustment is no big deal, and the early plates look cleaner as they do not have the "dimples" around the edge for the shoe supports like the later plates.
 
Thanks for the info re 35 rear drums, I didn't know they would work with hydraulics.

Mart.
 
I picked up about 50 used brake shoes from an old Ford repair dealership. The 46-48 shoes had wear down by the pivot point whereas the 39-41 style usually did not. The ones that did had shimmed linings.

My OPINION is that the later style shoes adjust for wear better than the early style, and with more shoe area making contact should stop a little better especially if you have worn brake drums.
 
Arc-grinding new linings to properly fit the newly-machined drums will be of great benefit with either style of brake... followed by proper adjustment of the 39 - 42 anchors. Most people like the 46-48's better because they don't have to deal with the anchor adjustment, and many do not understand the anchor adjustment purpose, and didn't back then... so the new 46's were made "fool" proof!!!
 
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