Can Anyone Help On These Brake Drum Size

Starting to get my newly bought 65 CJ5 ready for movement. Runs and now has new springs without 3/4 of the leaves broken so time to move onto the non existent brakes. Kaiser is running a 10 percent off special on brake bits so pulled the wheel to see what I got there. A bit confused on exactly what I have as I haven't seen a drum on a 4 wheeled vehicle in a decade. To me from that I'm assuming this is a standard 9" set up but hoping someone can confirm or deny it. I do know I don't have the s hard lines but rather the soft line going to the cylinder. From my measurements via a board on the top and the bottom I am getting about 10" outside diameter of the drum. It does have 3 bolts holes in the drum which looks like the 9" but being somewhat uniformed about drums can someone confirm for me that seems about what that the 9" set up is so I can get a full replacement set up on order. Last inspection was 78 so not worth trying to save anything except the pedal imho. Thanks and for not a Jeep or even an American guy I'm so far enjoying the project. Amazed how easy things are coming off.

 

All CJ brakes prior to 1966 Dauntless was a 9” Bendix brake system.
Otherwise in order to verify the brakes you have, a picture is virtually mandatory.

 

Yep, with Jeeps this old things like brakes are often changed, so pictures would help.

Your mention of "three bolts holes in the drum" probably indicates drums for a M38A1 were used at some point. Same Bendix 9" brakes for M38A1 and CJ5 but the military had three screws holding the drums to the hubs, and the CJ usually had swaged wheel studs, neither of which are needed.

Think Ken must have meant all CJ5 brakes prior to the 1966 Dauntless were 9" Bendix.

 

I had some tux parks that were pre 66 with 10" brakes.

 

The CJs also used three screws.

 

None of the CJs I have owned had the screws in the drums, but I have only owned a couple of Jeeps later than CJ2A.

The 67 CJ5 in my avatar had swaged studs before I converted it to 11" brakes, the two sets of M38A1 surplus axles I have had the screws in the drums which let me to think that was military specs. The swaged studs, or the screws serve no real purpose other than to have held the drums in place on the assembly line, and cause some aggravation to whoever does the first brake refresh on the Jeep.

 

This. Brake upgrades are common on old Jeeps (because the 9" brakes suck)

 

Early editions of the CJ had the same features as the military. I have three screws and no swage on my '56.

 

If I were faced with buying new parts anyway, I would convert to 11 inch brakes if I could find the parts. Any extra cost would be well worth the conversion effort.

 

OK garage gnome, I have never schooled myself on the Tuxedo Parks. I did not realize they were ahead in the brake department.

Old Pappy, I believe you refer to the pre 1953 3B brakes as Lockheed’s ?
I have inadvertently lumped them together with all the other later 9” Bendix brakes.
Yes those pre 1953 Lockheed’s are certainly all swaged drum brakes.
Beginning with 1953 cj-3B all 9” cj drums are mounted using the 3 countersunk screws
This specifically implies that 3B cj5/6 hubs are drilled to accept those 3 drum screws beginning in 1953.

Yes the 1953 -1971 9” CJ Bendix brakes were of 2 eras. Prior to 1959 the front wheel cylinders used inverted flare “S” tubes. After that the front wheel cylinders were fitted with frame mounted hoses.

 

Makes sense that the early CJ5s, especially from the 50s, would have the same hardware as the M38A1s, since both were coming off the line at the same time. I have never owned a CJ5 that early. Until the last few years most of the Jeeps I have owned have been between 1945 and 1951. The last government contract I am aware of for M38A1s was the Marine contract in 1963, when the Marines rejected the M151 being adopted by the Army. I have two sets of Marine surplus M38A1 axles, likely from that contract, and both have the screws. I have had two 67 CJ5s, the one in my avatar picture and another that I parted out, both had swaged studs.

I too would upgrade to better brakes rather than buying the parts to rebuild the old 9" brakes, but if originality is important the 9" Bendix brakes are superior to the 9" Lockheed brakes used from WW2 through CJ2A production.

 

My 11” brakes about threw me over the hood today when a mini suv was creeping through the gas station parking lot , thanks Andy! The XJ pedal/booster add to that exponentially. I’ll add the 11” rears when it cools down

 

Ken,

I can bring an example of a set of 67 CJ5 hubs with brake drums still attached by swaged wheel studs to the reunion if you want to see for yourself. I suspect that while military Jeeps were coming down the line they used the same parts for the civilian Jeeps, and that would have included CJ3Bs. I also suspect that once the military contracts dried up in 63 they probably went back to swaged studs to save a buck or two, and they certainly had the equipment for that since it was SOP from 1942 to at least 1948.

 

Spence,

Glad you like the 11" brakes. They are certainly an improvement over any of the earlier 9" brakes. I have converted most of my Jeeps to 11" at least on front, but all four on my CJ5. The backing plates are getting difficult to find, which is causing me to look a little harder at disc brake conversion for my current project, at least on front.

 

Andy, never knew about the late swaged drums either so I checked the books.
Your correct. Apparently jeep started using an updated form of swaged drums from 1967 - 1971 on the 4 cylinder CJ’s only. Due to updated part number those late 9” Bendix certainly are not identical to the CJ2A nor Cj3A swaged drums.

Besides 11” Bendix I consider the CJ 10” Wagner brakes to be an excellent upgrade for 4 cylinder CJ’s in particular. They are plenty big enough for slower jeeps and have better rock/debris sealing characteristics than the 11” Bendix brakes.
The 10” Wagners typically sourced from Dauntless CJ’s can be found with or without the self adjusting mechanism.

 

With the earlier inboard drums the swaged studs made some bit of sense. When they started using outboard drums there was no reason to swage the studs, so I was a bit taken by surprise when I got into these CJ5s, both 67s.

What Ken just posted clarifies my mystery a bit, and supports my suspicion they reverted to swaged studs to save a buck on the assembly line, or it may have had something to do with the transition from WO to Kaiser, both companies were in decline and probably cut costs wherever they could.

 

Are yours the USMC version? They had lockers.