converting to power brakes?

[jwillys]

I have an older (late 60's CJ5 ) with a Dana 44 rear and Dana 30 front. It has drum all around. I have no power brakes. Whats the best way to upgrade without breaking the bank... I really want to upgrade to power brakes and steering. I have the Dauntless Buick 225 V6 v6 btw.

 

[BajaEdition]

First, as we have asked you to before
go to your cp and add the info on your Jeep
that way we can check and see what we are dealing with
not doing so, makes clear answers hard to do
we have asked you to do such in other post you have made

Now. unfortunately for 71 and earlier cj5s there is no cheap and easy way to add power brakes.
the problem is that your entire pedal system is on the floor, not hung from the firewall like a more modern vehicle, to move this you will have to redo not just the brakes but the gas and clutch system also. You will need to get a firewall backing plate so you do not stress the metal from where you hang the stuff from, add the pedal system that matches that plate once it is welded in place, get a hydraulic clutch system and install that, get a cable to redo the accelerator cable and do that, get a power brake master cylinder that matches the pedal and firewall plate and add that.
once the MC is in you need to design new lines, more than likely you have a single stage MC and will need to address new brake plumbing. I would use a adjustable compensation valve so I could tune the brakes.
Now seeing all that work, I just replaced the MC with the kit Herm the Overdrive Guy sells, see our link area, and put disc all around, divided the brake lines to a 2 stage system and put in the comp valve.
I can say they are not power brakes, but then they stop a lot better than the drop the anchor and hold on style OEM brakes.

 

[ThisGuyUKnow]

First, as we have asked you to before
go to your cp and add the info on your Jeep
that way we can check and see what we are dealing with
not doing so, makes clear answers hard to do
we have asked you to do such in other post you have made

Now. unfortunately for 71 and earlier cj5s there is no cheap and easy way to add power brakes.
the problem is that your entire pedal system is on the floor, not hung from the firewall like a more modern vehicle, to move this you will have to redo not just the brakes but the gas and clutch system also. You will need to get a firewall backing plate so you do not stress the metal from where you hang the stuff from, add the pedal system that matches that plate once it is welded in place, get a hydraulic clutch system and install that, get a cable to redo the accelerator cable and do that, get a power brake master cylinder that matches the pedal and firewall plate and add that.
once the MC is in you need to design new lines, more than likely you have a single stage MC and will need to address new brake plumbing. I would use a adjustable compensation valve so I could tune the brakes.
Now seeing all that work, I just replaced the MC with the kit Herm the Overdrive Guy sells, see our link area, and put disc all around, divided the brake lines to a 2 stage system and put in the comp valve.
I can say they are not power brakes, but then they stop a lot better than the drop the anchor and hold on style OEM brakes.

Baja, Is there a difference between the later model cjs like say 80's and the op's cj as far as how thick the metal is on the fire wall? And under the dash between the fire wall and the dash? Like are the steering components in a different place? Or anything drastically different like that?

 

[jwillys]

Is there a way to purchase disc brakes from a donor Bronco or something and use them instead of buying all new stuff from Herm? I will be ordering his dual master cylinder kit and then converting atleast the front if not rear to all disc. I would think that it would be possible to find good used parts at one of my local salvage yards etc. I found a steering gearbox from a 96 Bronco for $45 locally. I would think I could buy disc brakes too and make them work. Any suggestions?? It just seems like $650 for the front only brakes is a lot from Herm. I know his are new or remans, but I am just being frugal.

 

[BajaEdition]

Baja, Is there a difference between the later model cjs like say 80's and the op's cj as far as how thick the metal is on the fire wall? And under the dash between the fire wall and the dash? Like are the steering components in a different place? Or anything drastically different like that?

until 71 the pedals came through the floor
after 76 they are on the fire wall
I am not sure about 72 to 75

but he has a late 60s setup so he has a problem with the placement of the MC

 

[BajaEdition]

Is there a way to purchase disc brakes from a donor Bronco or something and use them instead of buying all new stuff from Herm? I will be ordering his dual master cylinder kit and then converting atleast the front if not rear to all disc. I would think that it would be possible to find good used parts at one of my local salvage yards etc. I found a steering gearbox from a 96 Bronco for $45 locally. I would think I could buy disc brakes too and make them work. Any suggestions?? It just seems like $650 for the front only brakes is a lot from Herm. I know his are new or remans, but I am just being frugal.

the herm setup is using GM truck brakes, you need to find a mounting plate and Calipers if you want Junk Yard Brakes.

 

[jwillys]

which model of chevy truck brakes do I need? Will disk brakes that are meant for power brakes, work with Herm's set up with the upgraded master dual master cylinder? I suppose I just need to find a truck with 44 rear if I do the rear, and then a 30 front for the front... what am I missing here. ( I just junked a set of 4x4 chevy axles with disc up front....dang) Please fill me in if you would be so kind. I took a pix of my differentials and put in my other post. I am at my other pc right now and don't have the pix to post here. What bracket are you talking about? a bracket to hold the calipre??

 

[BajaEdition]

you will need to source the mounting plate GM uses on trucks with Dana 30 or Dana 44 axles, that will mount direct to the Dana 30 you have in the front. what ever calipers is on that, trust me GM does no make a ton of different calipers for trucks.
also grab the disc
then go out and order new hubs, I would not use used hubs, and new bearings, while at it get new lug bolts that have long enough press flanges to hold the disc on.

PS thanks for filling out what you know about the Jeep, it really helps us answer questions because we know what we are looking at.
could you post a pic of your front axle with the brakes off so I can look at it.

 

[BajaEdition]

there is a guy on Ebay that is selling the mounting plates for 78 dollars a piece.

 

[jwillys]

no problem. I will post much more when I start tearing into it. Just trying to get a plan of attack. where do you start???? lol. Looking forward to it. I will post the pix as soon as I can. T/hanks

 

[BajaEdition]

seeing how we are still trying to date the frame, can you crawl under there and tell us what type of MC you have, a single or a double?

 

[jwillys]

what does the guy on ebay have it listed under? tried chevy disc plates and chevy disc mounting.... nothing . T?hanks

 

[BajaEdition]

GM/Jeep dana 44 Disc Brake CALIPER MOUNTING BRACKET,Backing Plate,73-91 1/2 ton on eBay!

 

[BajaEdition]

here is a write up on it
Early Jeep Disk Brake Conversion - Timeless Tech Drum to Disc - Jp Magazine

 

[jwillys]

Heres the pix of the hub and mc

 

[BajaEdition]

thanks
now first, that is a 2 stage MC, that is great, pull it and rebuild it, when you do pull the back pressure device in the front outlet.

second, that is not a Dana 30 axle, it is a closed knuckle D25 or 27, I have some great news for you
if you want a Dana 30 , you can find a narrow track one that takes Jeep disc.
If you use that axle there you will need to learn how to take care of a closed knuckle, plus the bearings are different that need to be sourced. Your choice,

If I were in your shoes, Because you need to rebuild that axle anyway, I would go and find a Dana 30 from a NT CJ5 with disc on it anyway.

 

[jwillys]

Sweet! THAT IS WHY I LOVE FORUMS! I will start searching. Any tips on where? What does a narrow track measure or what defining characteristic do they have?

 

[BajaEdition]

Sweet! THAT IS WHY I LOVE FORUMS! I will start searching. Any tips on where? What does a narrow track measure or what defining characteristic do they have?

All CJ 5s have NT axles, so that is a given. I think a late 70s with disc is what you are after. I do not know the gearing in your present axle, but finding the same gearing is a huge plus. I would do a craigs list search, there are search engines for Craigs list that you can do according to how far you want to drive. once you get there try to get the tie rod and drag link with it, as well as any steering stabilizer. and of course try to get the calipers and rotors if they are there,
Oh if it does not have the knuckles for mounting disc, move on. once you get it home rebuild it and seal it up, any difficulty will show up then.

 

[jwillys]

Just found a good Nt with all hardware needed fir $100. He also has a Dana 300 and T-18 6.32 combo in great condition for possibly $400. The Dana 30nt has 4:10. Which way should I go? Find 4:88 for the 30? Will the 4:88 in my front work on the new nt 30?

 

[Saddle Tramp]

1972 was the first year that CJ peddles hung on the firewall. In 1972 the clutch was activated by a cable with a ball on each end that fit into brackets, one on the peddle the other on the clutch fork. The balls were notorious for pulling off under the strain and leaving you high and dry with no clutch. By 1973 Jeep changed to the rod system. 1977 is the first year disk brakes were offered on a Dana 30 CJ. The spring perches on a 1977 & newer axle will be wider by about 1/2” than the 1971 & older version. I’m not sure if you can make that work without changing something; I’d try and pick up the spring plates with the axle if possible as you most likely will need them.