Technical BRAKES, Ultimate Guide To Fitting '39-'48 Hydraulic Brakes To Your 'A'....

You guys may be interested in how Dave Wilton solved the problem on the rear.
mtcarproducts.com

 

No problem, are you going to the Hayride? I can take it there....

 

I wish I would have seen this 3 weeks ago. I just did this. I found out the hard way what needed to be done, It was exactly what you said even down to the chamfer on the brake shoe. I made a master cylinder mount that came from the frame to put where the stock pedal could still be used. I think I have a picture of this at home I can post later for those that are looking for a less expensive route. I just used a 2 reservoir master cylinder from speedway because thats what I had. A single stock 40 ford type would probably be better? Also my backing plates were hitting the radius rod and I had to grind a little on the backing plate.......My 2 cents Thanks.

 

This is a really good post with excellent replies, too. I really like the option of spacing out the drum on the hub--I feel that axle shims are unsound, as the juncture between hub and axle needs to be super tight. Cars with shims will likely end up being driven by the axle keys. I believe Wilton does his that way, though I can't find my way back to that on his site.
Model A axle housings come in several variants, and some don't really have enough flange thickness to be cut for clearance--plus that's a pretty big job, and requires a friend with a gigantic lathe.
There is SOME extra width in Ford hydraulic drums, generally seen as an unworn step where brake surface meets the front plate of the drum, that might be utilized for some extra clearance in there.

 

Ok Hambers,

I did the rear '46-48 Ford juice brake conversion this weekend on my A-V8 Sport Coupe.

This what I found:

First, don't cut the hole in the backing plates. Just rotate them forward 20 degrees until the spring hanger clears and drill four new holes. I did this by puting the backing plate on in the correct position using large welding vice grips and drill the new holes from behind. No need for a drill press unless you are just anal about that kinda stuff.Also by rotating the backing plate forward you are able to have clear access to the wheel cylinder for running brake lines which normally would be impossible with the placement of the spring hanger. This method worked great and saved time.

Second I didn't need to machine the backing plates and drums. I used two axle shims and torqued it 200 lbs. Before the shims, the drum binded up once it was torqued, but afterward it was just fine.

As for the front axle conversion I did not use any of the Model A stuff and built my own dropped axle front end with '40 juice brakes so I have no comment.


Have fun!

Tex

 

ok I found the picture. I really had to shrink it, so I hope its clear enough.
This is how I did the master cylinder.

 

Thanks for the pic, Roadburner. How are you going to connect the brake pedal to the master cylinder?

 

I just made a new tab and welded it on the bottom of the pedal.

 

<<<There is SOME extra width in Ford hydraulic drums, generally seen as an unworn step where brake surface meets the front plate of the drum, that might be utilized for some extra clearance in there>>>

That extra width is more thsn 1/4 inch. I am using 2" shoes

 

According to a guy on Fordbarn, "There was an article in the F.A.S.T. (Ford
A Speed Technology) magazine about how to do it, with photos showing the adaptors that Dave W. makes. Generally, a spacer was used
on the brake plate to move it outward for
clearance and the drum was also spaced out."
Bruce Lancaster (or anyone) Do you have a copy of this info?

 

I believe Wilton used a repro prewar type hub and drum and put a spacer between hub and drum to get the requisite clearance without resorting to axle shims. I know I saw a picture of this, but I could not find it on his site.

 

Look here:

http://www.rodandcustommagazine.com/techarticles/135_0507_lincoln_brakes/

And here:

http://www.mtcarproducts.com/stuff.htm

 

Ahhh! Now we're getting the ultimate drum brakes for the rear of the Model A! The articles and pictures show that if a spacer is made to fit the A rear axle, then a modern backing plate (74-76 Chevy Big Wagon or any other 12"backing plate, 59 Olds or Buick?) with self energizing, self adjusting 2" brakeshoes will easily fit. Wilton is making his own hub and brake drum, but its easy to see that the 1940 hub can be separated from the drum and another spacer added there with new lug studs.
I will take pictures as I do this and will post them here.
Thanks Bruce!

 

I had this note in my files from Fordbarn or maybe Ahooga.com:
The 'V8 Times', Sept/Oct 98 Issue, pages 46 and 48, quotes several Ford Service Letters and later corrections. The final direction on tightening axle nuts reads: "tighten nut 356074-S to 200 to 220 foot pounds; then continue tightening to the next castellation providing final resultant torque does not exceed 275 foot pounds.


On the front brakes:
It certainly doesn't hurt to plug and redrill the holes, but the backing plates only see shear, so slots should be fine- the key is to avoid any slop and not to make them any bigger than necessary. I added washers to reinforce the area and hold the centering rings in place.

http://www.jalopyjournal.com/forum/showthread.php?t=122603&highlight=buick+tech

On the rears:
I have heard that it is better to remove enough material from the lips of the drums and backing plates to avoid the need for axle shims altogether. The 16 degree rotation is another popular way to skin the cat. Lots of references on Fordbarn and Ahooga.com, and Clings sells the backing plates modified this way. www.clingsaftermarket.com

If you go with reversing/flipping the backing plates, the opposite sides&#8217; wheel cylinder bleeders will be at the bottom. The round hole in the backing plate can be modified so that the cylinder can be rotated to put the bleeder back on top. Be sure to use the original sides&#8217; wheel cylinders so the big bore end of the cylinder actuates the correct shoe. Flipping/rotating backing plates is a little easier, but I don't like the brake lines exposed and vulnerable below the axles tubes.

 

Excellent Post


I just gave away an original a front axle as well as 39 front and rears (complete).

Too much junk hangin around the shop.

I wish I would have kept the complete 39 spindles etc.

But when your tired of tripping over boatloads of heavy crap.....

.
..

 

Thank you!

 

Where do I get a front fitting kit?

 

Speedway sells the adapter kit to adapt '39-'48 Ford backing plates to the stock A spindels.

Streetrods are drivin' by Chevy, Hotrods are powered by Ford!

 

thanks for sharing the information

 

Looking threw this thread, there’s a lot of awesome info. Found some other potions are for parts and setup. Figured I’d share if anyone would want to know what I found.

Master cylinder and battery box. Pretty neat, keeps everything on the driver side with factory peddles.
http://www.bolingbrothers.com/model-a-master-cylinder-battery-box-assembly/

Set for the rears, you still rotate the backing plate 20' forward, and drill new holes. Shave and dimple the back plate.
https://www.speedwaymotors.com/Bend...r-1937-48-Ford-Rear-12-x-1-3-4-Inch,7374.html

Hubs for the rear
https://www.speedwaymotors.com/12-x-2-Brake-Drum-for-Bendix-Style-1937-48-Ford-Brakes,5847.html

Front kit, just bolts right up.
https://www.speedwaymotors.com/Speedway-Early-Ford-Spindle-Bendix-Drum-Brake-Kit,383096.html

 

bump, its a common question , I was looking for the answer myself so bringing this post back to the top for reference .

 

Just read the entire thread, great info and thanks to all contributors.

 

Yep.....must have missed it a long time ago.....but just look at all those views but yet not a near a comment.....