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Discussion Starter · #1 ·
Do you have to do anything special to replace the stock rear 9 inch brakes on the CJ3B with Ford Bronco 11 inch brakes? By anything special I mean other than removing the drums,backing plates and replacing with the Ford Bronco parts?
 

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IIRC, you may have to drill one extra hole in the Bronco backing plates. They might bolt up as-is... I just can't recall clearly.. but I know worst case you will need to drill one hole to completely match the flange pattern on the CJ axle tube flange.

You might want to check with the guys on the Flatfender forum at EarlyCJ5.net/forums

(I have a set of 11" front D30 EB brakes in my shed)
 

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Discussion Starter · #3 ·
I picked up the 3B last night, it has 11 inch brakes on the front already, I got the backing plates and drums for the back. I'm going to drive it like it is for a while and then start taking it apart.
 

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I installed 11" drums all around on my '71 CJ5.

I used postal Jeep drums, and drilled three rows of (18) 1/8" holes in the drums, 54 holes in each drum.
These holes allowed water and mud to be evacuated from the braking surface immediately, so I never had the old wet-drum-brakes-don't-work-on-the-trail issue.... very useful if you do much water crossings/mud holes. Additionally, drilling improved dry braking so that it stopped as well as 4-wheel disc, even with 33x12.50 Mts on steel wheels.

I detailed my write up years ago on EarlyCJ5.net. Others followed this idea, and made improvements in the process and the application. This is one of the truly great mods that can be done on a drum-braked rig.

Good luck with your B.. . post pics!
 

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Discussion Starter · #5 ·
I installed 11" drums all around on my '71 CJ5.

I used postal Jeep drums, and drilled three rows of (18) 1/8" holes in the drums, 54 holes in each drum.
These holes allowed water and mud to be evacuated from the braking surface immediately, so I never had the old wet-drum-brakes-don't-work-on-the-trail issue.... very useful if you do much water crossings/mud holes. Additionally, drilling improved dry braking so that it stopped as well as 4-wheel disc, even with 33x12.50 Mts on steel wheels.

I detailed my write up years ago on EarlyCJ5.net. Others followed this idea, and made improvements in the process and the application. This is one of the truly great mods that can be done on a drum-braked rig.

Good luck with your B.. . post pics!
I got a dual master cylinder kit with it, did you use one of those or did you change to a different master cylinder?
 

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My '71 had a factory dual-circuit master cylinder, but it was still an under-floor mount.
With all the mods I did on that CJ, I kept the frame-mounted pedals.
I have a couple sets of swinging pedals... if I had kept the rig longer I probably would have swapped to swinging pedals/firewall-mounted master cylinder & hydraulic clutch.
I ran the AA chain-drive clutch which was OK until you got the frame twisted... :rolleyes:
 

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Discussion Starter · #7 ·
Any tips or information on a proportioning valve. After the 11 inch brakes and the dual master cylinder conversion I guess the rear brakes can/will lock up . The front are already installed with the stock master cylinder. I have the parts for the dual conversion, that will be my next project.
 

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Discussion Starter · #12 ·
I just got a email from the person that sells the conversion kit. He said that no valve was needed with the drum brake kit. Now all I have to do is find another location for the brake light sensor.
 

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Just to be clear, the residual pressure valves and the proportioning valve are not the same thing. See the link I included above.
The kit probably does not need a proportioning valve, but certainly needs residual pressure valves. If the kit you are buying comes with a master cylinder I'm guessing the RPVs will be already installed, just under the fittings for each circuit on the mc body.

If you are already clear on this, sorry to repeat... I just didn't want you to miss this important aspect of the drum brake system.

HTH, good luck, post pics!! :thumb:
 

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BTW, who are you buying the kit from?
R&P ?

If so, big :thumb: for Rich & Paul !!

If you are buying elsewhere, you should certainly check out R&P 4WD, here:

RP4WD
 

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Discussion Starter · #15 ·
Just to be clear, the residual pressure valves and the proportioning valve are not the same thing. See the link I included above.
The kit probably does not need a proportioning valve, but certainly needs residual pressure valves. If the kit you are buying comes with a master cylinder I'm guessing the RPVs will be already installed, just under the fittings for each circuit on the mc body.

If you are already clear on this, sorry to repeat... I just didn't want you to miss this important aspect of the drum brake system.

HTH, good luck, post pics!! :thumb:
I believe the master cylinder is set up to have less braking pressure on the rear .
 

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Discussion Starter · #16 ·
BTW, who are you buying the kit from?
R&P ?

If so, big :thumb: for Rich & Paul !!

If you are buying elsewhere, you should certainly check out R&P 4WD, here:
I've already got the kit, it's marketed by : hermtheoverdriveguy.com .
 

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I believe the master cylinder is set up to have less braking pressure on the rear .
Not talking braking pressure here; talking residual pressure in the lines after the brake is applied and released.
Check with Herm to verify that the MC has residual pressure valves appropriate for drums on both circuits. It may be set up with residual pressure valve for disc on the front circuit (this is a common set up), and if it does you'll never get your brakes to operate correctly.
 

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Discussion Starter · #18 ·
Not talking braking pressure here; talking residual pressure in the lines after the brake is applied and released.
Check with Herm to verify that the MC has residual pressure valves appropriate for drums on both circuits. It may be set up with residual pressure valve for disc on the front circuit (this is a common set up), and if it does you'll never get your brakes to operate correctly.
Herm sells a kit for 'disk front and drum back', so that would tell me the back brake line from the MS is set up for drums. The kit I got was set to run drums both front and back so it is a differently set up MS than the one for the disk/drum mix. He also has a dual MS for disks front and back. It seems like he knows quite a bit about the old Jeep conversions.

The brake shoes and all the springs etc are supposed to be here tomorrow. Hopefully I can get the rear drums off without to much trouble, I don't have a wheel puller but I can rent one downtown if I need to.

I keep forgetting the camera........
 

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If Herm sold the kit set up for drums F&R, then I'm sure he will have the correct residual pressure valves already in place.
I've dealt with Herm before; he's a good guy. He sells quite a bit to the forum members at EarlyCJ5.net.

Looking forward to your pics!!
 

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If Herm sold the kit set up for drums F&R, then I'm sure he will have the correct residual pressure valves already in place.
I've dealt with Herm before; he's a good guy. He sells quite a bit to the forum members at EarlyCJ5.net.

Looking forward to your pics!!
2x-and anyone who would put a 3B pic on the web page header can't be too bad---
 
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