Disk Brakes

These are the field modifications I have made both authorized and unauthorized. The goal of any of the mods is to improve the jeep’s safety or reliability.

The WW2 jeeps use very small drums and require frequent maintenance in order to ensure maximum stopping power. Well, that seemed to translate into once-a-week adjusting. This is not a fun process. So after much research, I installed disc brakes. The setup is from the parts of two vehicles. The disc is from a 1978 CJ. The calipers and backing or mounting plate are from a 1978 Chevy PU 4×4 1/2 ton (front axle) along with the brake hoses that go to the calipers. In my setup, I had 1/8 inch of the top hat removed from the disc. This was necessary to ensure the correct alignment of the caliper/pads. Other options would have required either removing material from the back of the hub or grinding pad material off. Speaking of grinding, you will need to grind some metal from your front knuckles (this is to ensure clearance of the caliper.) You may also find that you will need to grind some material off of the ears of the calipers in order to clear your wheels. And now for the BAD news. You will not be able to run your 4.5 x 16-inch rims with this setup. I didn’t know this when I started. Since then a disclaimer has been added to the website I used. The website owner, Chuck P, seems very willing to share what he knows about the conversion. Check out his site for details. IN THE WORKS…I just received some information that in Brasil there is at least one company that manufactures discs, backing plates, and caliper kits that will fit the jeep and allow stock wheels. More as soon as I find out. Disk Part 2 This is another modification that I have done to my jeep in order to promote safety. This version of the disk brakes will allow the fitting of stock-size wheels which is an improvement over my earlier version of disk brakes.

Before you get into the article a word or two on the need for CAUTION. If you don’t know anything about brakes LEARN! If you don’t get this right you could injure yourself or someone else. Test! Test! and Test some more! After completing work on my brakes I drive the jeep around the yard, gradually going faster after each stop. This is to ensure the brakes are not acting squirrelly. Only then do I take it out into the neighborhood and test it some more before taking it out onto the local roads.

Other parts needed or used:

Master Cylinder
4 spacers for the front axles
20 long lug bolts
20 long lug nuts
brake pressure regulator

The first question is where can I get those disk brakes? They are made by SuperBreak Disks (that’s the way they spell it!) in Brazil. However, you can’t buy them directly from the manufacturer, you have to buy them from a retailer. The retailer I used was Calibre Offroad. Calibre didn’t have too much experience (none) with exporting parts. I started talking to Calibre in February 2002 and was not able to get the parts shipped to me until June 2002. Luckily I was able to enlist the aid of a friend of a G503 member. Paulino worked out the details. He was able to get the shipping cost from $400 UPS to $200 UPS. I guess they have competition in Brazil.

The retailer I used doesn’t appear to have a functioning website but Superbreakdisk has other representatives you can contact if interested. The owner of Superbreakdisk spoke English so I was able to discuss details with him before buying. Someone at one of the representatives may also speak English. Be sure to ask them about their ability to export. As far as shipping Brasil UPS can do it. Also, airline companies may take your shipment and deliver it as close as your nearest airport.

jeepdisk1sm

Picture above. In the first picture, you can see the disk. The next photo is of a modified and unmodified caliper mount. I had to take the caliper mounts for the front to a machine shop and have the hole enlarged (because I needed to add spacers, see below).The kit is officially for the CJ2A, CJ3, etc. with a DANA 25 axle. The third picture is of the parts included with the kit from Brasil. It had all the hardware necessary except for longer lug bolts. Note that the instructions are in Portuguese but it’s really not that hard to figure out. jeepdisk4sm

Above. I had adapters (first and second pictures) made to go behind the caliper mounts and the disk. This cost roughly $325 at my local machine shop. This was necessary because the axle of the MB/GPW differs from the CJ2A (actually the MB/GPWs have a DANA 23-2 axle) DANA 25 axles. When you install the kit without the spacers the disk cannot be rotated because it presses against the steering arm. With the adapters this is no longer a problem. The third picture illustrates the removal of the brake drum and installation of the longer lug bolts. jeepdisk7sm

Above. First, you need need to remove all of the original brake parts. Follow the directions in TM 9-803 for hub removal. Be sure to remove the brake backing plate and the brake drum from the hub as well. Install the spacer then the caliper mount, followed by the hub. Then the spacer goes behind the disk and then that unit goes over the hub with longer lug bolts installed. Next, install the calipers onto the bracket. The caliper is a standard Combi (Volkswagen van) part. The kit includes the SAE to the metric adapter for the brake lines. You have to assemble the caliper before installation but it was simple enough even for me! jeepdisk10sm

Above. Here’s where it gets a little ugly. I used a grinder to remove a little material from the caliper (you could use even longer lug bolts if you want to and perhaps a larger spacer.) and you also have to remove some material from the wheel itself. The civilian wheels that I am using have 4 spokes. Each spoke has some ears that are in the way of the caliper. I used my grinder to remove roughly 1/8 inch of material and then test-fitted the wheel. It took me about 5 hours to install just this one wheel, not counting setbacks that included discovering that the kit as delivered would not work. Trips to the machine shop to work out adapters. If I were to do the adapters again I would go with at least 1/4 inch to ensure plenty of clearance between the disk and the steering arm. As it is it just touches the plastic shield which will of course wear. I will need to keep an eye (or two) on this to see if any serious wear develops. Finally, I have that beloved NDT tread on my jeep! Well, at least on one wheel. Perhaps the rest tomorrow. You should know that the manufacturer is a great guy named Mr. Suzuki. I spoke to him on the phone and he even had pictures emailed to me to help show how the kit is installed. Unfortunately, the MB/GPW, even though it is basically a DANA 25 it is still different (doh, that’s why it’s called a DANA 23-2). Also, Mario at Calibre Offroad is very friendly and we traded emails many times. He had never tried to export parts before so he was stumped the first time. I think that he should be able to handle the export next time should anyone want to try it. By the way, both gentlemen speak English very well which is good because my Portuguese is non-existent. So how much did it cost? Since the front and rear axles on the MB/GPW are basically the same (except for the obvious), I bought two front kits. Calibre Offroad offers a different kit for the rear for the CJs. I don’t know much about that kit but I think it includes the parking brake setup. Parts Cost 2 front axles kits $360 UPS shipping from Brasil $200 Customs fee $150 4 spacers to adapt the kit for Dana 23-2, front axle only $330 Total $1010 Not included in the total above are the cost of the Wilwood Master Cylinder kit (in theory you could use the original but would have to remove the valve), brake pressure regulator (to control/delay the rear brakes from engaging), lug bolts, and lug nuts. I bought those parts (except for the lug bolts) when I did my first disk brake conversion on this jeep with the Chevy/CJ setup. That’s about it for now.