Master Cylinder and brake converstion for a 72 CJ5

I am in the middle of a axle swap and SOA build on a 72 CJ5. So far things went well in the axle swap and i will now have disk brakes on the front. I swapped out the old Dana 30 for a Dana 44 from a 79 waggy. I also plan to use the steering box and pump on this jeep from that waggy.
My issue right now is attempting to adapt the Disk brakes from the waggy to the CJ5 chassis. I went ahead and bought a master cylinder for a 78 CJ7. The reason i did that is that CJ had disk brakes and an unboosted master cylinder. My question is how do i start getting these two systems working with each other. I noticed the MC has two diffrent sizes of outlets and i know my current chassis has only one size.
Anyone that has done either the Power steering or brakes that would like to help me that would be great.
Thanks
CH

 

Bill Ansell's Brake Bible is Must Read for anyone working on brakes on their Jeep.

The answer to your above question and all the other questions you will (or should) have are there.

I'm not a fan of the Pirate Board but Bill Ansell really does his research and his tech articles are all worth the read.

 

I installed disk brakes on the front of my 72 about a year ago. I also used a 78 manual brake m/c from a CJ7, I had to shorten the m/c pushrod about a 1/2 inch and fabricate a bracket to mount the stop lamp switch to contact the brake pedal arm because the 72 m/c had a pressure switch to turn on the brake lights and the later brake systems have the mechanical switch. You will need to get a proportioning valve also, I found a used one from a jeep salvage yard for $60.00 with all the odd size fittings still attached, new proportioning valves are about $160.00. However a Napa auto parts store in my area had all the odd size fittings in stock. The small reservoir which is toward the front of the m/c is for the rear brakes and the large reservoir is for the front brakes, I mounted the proportining valve below the m/c on a bracket that I fabricated and attached to the lower steering column mount. With the proportioning valve mounted with the electric switch facing up and the large port that comes out the end (which is the outlet for the rear brakes) facing straight back, there are two smaller ports on the other end of the proportioning valve (one faces straight down and the other faces up at about a 45 degree angle) that are for the front brakes. You will need to run new lines to the front brakes because the drum setup used one larger line with a T inline to supply fluid to front ,the the disk setup used 2 smaller seperate lines for the left and right wheels (BTW it doesn't mater which of the small ports on the end of the proportioning valve goes to the left and right wheels)The lines from the master cylinder connect to the two remaining ports on the top of the proportioning valve on either side of the switch (which is for a brake warning light) these lines have to cross, meaning that the line from the large rear reservoir of the m/c connects to the port toward the front of the vehicle (on the end that has the 2 small outlet ports for the front brakes) and the line from the small front reservoir on the m/c connects to the rear port on top of the proportioning valve . If you are doing this yourself you wil need to be able to cut, bend and flare your own brake lines. I have a pressure bleeder, but you can pump bleed the brakes but it might take some time because you will have alot of air in the system.
Good Luck

 

Also I just finished installing power steering on my 72 CJ5 and depending on which engine you have I can probably talk you through that upgrade also. I have a 258.

 

I knew the pushrod was too long when tried to bolt the master cylinder to the firewall, the pushrod was seated in the piston in the rear of the m/c about a 1/2 inch before the m/c was flush against the firewall. With the master cylinder bolted to the firewall you should have a small amount of freeplay in the brake pedal before it starts to move the piston. I found some adjustable clutch pushrods that I was going to try and modify but it was less work to just grind small amounts off my existing pushrod until I had the amount of freeplay that I wanted. Mine might be slightly different than yours because about 10 years ago I did away with the cable clutch system that they used in 72 only and installed the pedals and clutch linkage from a 73-75, but I am still using the 72 brake pushrod.

 

Thanks for the responces on the push rod, it seems i did have it a bit long, i might still have it to long and will need some sort of an adjustable rod. My question is now do you guys usually have much power with this set up. I am not sure if it is going to be as strong as i was hoping.

 

One other thing, if not using a power booster make darn sure you use organic pads, not semi-metallic. Organic pads can be used with manual brakes with no issue. Semi-metallics are designed to be used with a power booster and have a much harder compound than organics. This means without a booster the semi-metallic pads will give poor stopping ability.

 

I have semi metalic pads on mine with manual brakes and it requires a little more pedal force than it did with the 4 wheel drum setup in normal operation but when trying to stop quickly at highway speeds with the Jeep loaded or when coming down a steep hill on the brakes I am wishing for a little more power. However if you have big tires then it will be worse (mine has 30x9.50s for now) I am going to put power brakes on mine soon, I have 2 hydro boost assemblies that someone gave me, I just don't think that I need quite that much power so I will probably just go with a vacuume booster.