Doing Brake Linings (on a '25)

[MikeC5]

I promised to post some photos of doing the brake linings...

Photo 1 - the linings came pre-bent to almost the right radius. I kept them in there until ready for use.

Photo 2 - I decided to cut using a hack saw. I was able to cut the thinner linings for the parking brake with sheet metal shears but these are tougher to do that.

Photo 3 - I decided to add a bit of chamfer to the leading and trailing edge using an ordinary metal file.

Photo 4 - I used plenty of clamps to hold it in place. You want to make sure the lining is tight against the band before riveting.

Photo 5 - Clamped and ready to transfer drill (don't even think of pre-drilling the holes)

Photo 6 - Transfer drilling the holes on the first two rivets. Rivet from the mid-point of the lining piece first, then work out toward the ends.

Photo 7 - Using a spotface tool with pilot equal to hole diameter (drill diameter really). I got it from McMaster-Carr, which is also where I got the linings and brass tubular rivets.

Photo 8 - Spot faced lining. I tried to get these to a depth about 2/3 of the lining thickness (0.170" for the 0.25" lining)

Photo 9 - This is a 3/16" diameter semi-tubular rivet with length of 5/16". The head is 3/8". I'm not certain if this is the original rivet size used when new. The parking brake shoe used 9/64 diameter. However, whomever did the brakes the last time used the small rivets in the bigger holes on the external bands.

Photo 10 - This is the rivet setting tool I got from Meyers. It worked great for the e-brake but the rivet end setter seemed too small for the larger diameter rivets.

Photo 11 - This is the anvil from the Meyers tool. Luckily it was 3/8" diameter on one end and 1/4" on the other (1/4" is used for the e-brake rivets)

Photo 12 - This is the rivet setting tool I used for these bands.

Photo 13 - Here's the set up for bucking the rivet. I clamped a dolly into the vice and set the rivet anvil on top.

Photo 14 - Ready to hammer.

Photo 15 - The bucked rivet

Photo 16 - The finished segment.

[MikeC5]

Woops, here are the photos... I tried to get them to post in order but I couldn't figure it out. Start from the bottom and work your way up right to left.

[Guest 1930]

Great photos Mike, I have only had to do one set of shoes on one of these early cars and that was some time ago and I paid someone to install the linings. You say they came pre-bent, I watched the guy do mine and he used a material that was cut from a roll. It was a flexible banding material.

Did your lining have some sort of backer attached to them? Sounds like they did I guess and you were concerned with this becoming out of shape.

What was the backer material. If there was a backer or stiffner already attached to your linings than why were you concerned with the depth of the countersink, wouldnt you have just been able to countersink all the way down to the backer or stiffner.

I guess I am mis-reading something.

[jpage]

The company I used to work for relined brakes and I have done my share. Always start to rivet from the center outward. Do not countersink more than 2/3's through the lining. Always use a rivet diameter the same size as the holes in the shoes as smaller rivets will start to move after a while. Always drill each hole one at a time with the lining clamped tight. Always use brass brake rivets; they have a little wider head with a flat surface and the brass will not damage the drums if they come in contact with the drum. Always keep the lining clamped tight to the shoe when riveting to make sure the lining is in contact with the shoe. Never over tighten the rivets. Tighten only enough to hold the lining securely to the shoe. An overly tight rivet will crack the lining and it will eventually work loose. The foot operated rivet machines were good for this because you could preset the pressure on the rivets. Chamfer the ends of the linings and always arch the finished shoes to the drum by sanding them to fit. When chamfering the ends sand away a little at the top contact areas so the lining does not drag at the ends.

[MikeC5]

No backer on the linings Jason. I had to be careful not to spotface too deep. They probably did come off a roll but the pre-bend was helpful. It's good to hear that I didn't do too badly from a pro.

[jpage]

I have never seen a backer on any bulk or preformed lining. The type in the photos is heavy duty woven lining. It used to be made of an asbestos material with a brass mesh moulded in. It has good friction and average wear.Another type you may see is a flex-moulded lining,which is a slightly softer,gray material impregnated with small bits of brass wire. It wears a little quicker but has better friction qualities than heavy duty woven. Both of these types work well on antique cars with a slower top speed and which have no precast lining available. I would not recommend them for post war vehicles! Most all of these materials are available in a bulk roll(hence the prebend) but are not made for specific applications. Always make sure that you use the correct thickness when relining brakes! Always make sure that you use the correct length rivet;too long and it will never tighten enough,too short and you'll not get the holding qualities that you need or smash the holes out!

Edited September 23, 2012 by jpage (see edit history)

[Aussie Dodge]

Mike, thank you for a great detailed post with excellent photos. I am just about to install new brake linings in my 25 Dodge. Just a quick question, my old dodge has no linings left on the internal brakes so I have no idea of the length of each lining. My old mechanics guide book suggests the total length of lining for the internal shoes is 5 foot, 11 inches per vehicle, but there is no guide as to length of the linings inside each brake drum. I have spoken to a couple of local brake mechanics and they have suggested that there would be a primary and secondary lining within each drum and that these can be identified as one lining is longer than the other. The shorter lining (primary) typically faces the front of the vehicle and this apparently has something to do with the amount of additional pressure that the braking system can apply to the brake drum when the vehicle is moving in the forward direction.

Have you encountered this situation?  or can you provide information on the length of the brake linings for the internal brake on a 25 Dodge.

Regards Aussie Dodge

 

[Spinneyhill]

On 12/28/2016 at 10:51 PM, Aussie Dodge said:

My old mechanics guide book suggests the total length of lining for the internal shoes is 5 foot, 11 inches per vehicle, but there is no guide as to length of the linings inside each brake drum. I have spoken to a couple of local brake mechanics and they have suggested that there would be a primary and secondary lining within each drum and that these can be identified as one lining is longer than the other. The shorter lining (primary) typically faces the front of the vehicle and this apparently has something to do with the amount of additional pressure that the braking system can apply to the brake drum when the vehicle is moving in the forward direction.

 

So that is 35.5" per side or say 18" per shoe? The primary shoe is usually longer, say 18.25" vs 17.25"?. The primary shoe is pulled into the drum as it rotates so if the actuating mechanism is at the top, it is the front shoe. If it is actuated at the bottom, it is the rear shoe. When reversing, the shoe roles are reversed. If you have two  actuating mechanisms, you have two primary and no secondary shoes. The primary shoe goes close to the actuating mechanism whereas the secondary shoe can be short of the actuating mechanism. The only reason for a shorter shoe is to save brake lining material - it doesn't do much braking so save money and don't put it in?

 

If you have 12" dia drums, you have 37.7" of circumference so 35.5" of shoe sounds about right?

 

 

[MikeC5]

I just happened to have the brake drum off (replacing rear axle oil seals) and so was able to take a couple of photos and measurements.  I was able to cut the brake lining to appropriate length easily with a hacksaw.  They both (top and bottom) measure 18 and 3/8" length.

[Pete K.]

Thank you for posting this Mike