Disc Brakes Or Power Booster?

Hello all. I have a brake upgrade question for everybody. I'm going to put in work on my 57 M38A1 and I'm trying to figure out what path I should go down. I know this has been a well discussed topic, so I apologize if I'm beating a dead horse. At some point in the past, a previous owner modified my M38 and threw a Dana 30 front end and Dana 44 rear end from a early-70s era CJ5 under it, so I actually already have 11 inch drums all the way around. I've read that some people recommend just going with the bigger drums since it's an easier install and you get almost the same braking power as discs, but I'm still not all that happy with them. I also have a dual reservoir MC mounted to the firewall along with swinging pedals already. However as these are also out of the same era of CJ5, they are still aren't power brakes. I want it not only to have better stopping power, but an easier pedal feel so my wife can feel safe driving it. So here are my questions:

Should I go ahead and put discs brakes on the front axle? Will that really gain me more stopping power over what I already have? Or should I just add a power booster to the MC to gain the pedal ease I'm looking for, and will the 11 inch drums be able to handle it? Or do I need to do both? If I put discs on the front, I will be buying a kit so I get new parts and it's done correctly, but I don't want to spend $500-$700 if it won't make much of a difference. Any insight would be very much appreciated.

 

I’d keep the drums if you don’t ever plan on tackling water crossings and don’t mind the extra steps for maintenance/replacement. The discs don’t offer much more stopping power over dry, clean 11” drums. Adding a booster is a good place to start.

 

I'm kind of surprised that you don't have plenty of stopping power with your current 11" brakes on all 4 corners. Do you have auto adjusters on all? Maybe get a power bleeder and see if you can improve what you have.

 

Ditto. R&r those 11's. Add a booster if needed but with any reasonable tire size you should be smacking the windshield with your forehead.

 

Yeah, I was surprised too when I drove it the first time. I felt like the stopping power I would associate with the original sized drums. I haven't the chance to do much with it yet, but I'll pull the drums off and make sure I go through each set before I make any decisions about swapping to discs. Although I plan on going off road some, it won't be anything ridiculously crazy. If the 11s provide adequate stopping power, I'm more than happy to keep them and save the money rather than swapping. As for the MC, I am just a little concerned my wife won't like driving it without the comfort of the power booster, but I can always add one later. I had another M38A1 about a decade ago, that someone put a large power brake booster on, but left all the original brakes. It actually stopped great, but looking back I'm sure it was probably murder on those poor little 9 inch drums, lol.

Thanks for the advice!

 

I too started with drum brakes. I now have 4 wheel discs. I used a power brake booster and master cylinder out of a 84' S-10.

 

Nother vote to r&r the drums.
I did disk for cost and parts availability reasons but that snowballed. Since you have the backing plates the hard part of finding backing plates is over.

 

I decided to go with Geo disc up front and 11” Bendix in the rear along with a dual master. I chose the disc as I plan on doing some forest roads and they may have streams, so just in case. Now, in all fairness, the 9” were not in the best of shape when I took them apart with lots of yuck everywhere from leaking over the years. They would stop but scary and definitely not a very fast stop. After the conversion, I felt they stopped so much better. I can slam them on and get stopped in a hurry. Not like modern cars but more than acceptable.

Now for your second part, the wife. My wife tried the new setup and said she would only drive it in an emergency. She grew up with a standard so she knows how to down shift to help the braking process, but was not comfortable with them. I bought a booster to install on our wagon when I get to brakes just for her. I will put in the 11” Bendix all the way around since I don’t really plan on river work on the wagon. At least for now. So my suggestion is going with a booster for your wife if she plans to drive it. Just my opinion.

 

I have drilled 11 drums all around on my CJ. It stops good but still takes a fair amount of pedal pressure...if the Mrs doesn't have strong legs she'd probably appreciate the power booster. I drilled my drums specifically to help with water crossings, but they're still not worth a damm when wet...

 

I did the front disc conversion on my '75 . Best thing I've done to mine . Major improvement, particularly with the wet & the stream crossings , like Warloch said. I was very fortunate to already have a '84 GM Hydroboost to go along with it :

 

I think this is the route I’m most likely going to take. She’s not used to manual brakes and would have a hard time putting the necessary force to the pedal. I want her to enjoy driving it, and I think power brakes would go a long way. That, and a new heater, lol.

I’ll just have to decide if I’m going to use a booster from a newer model CJ, or find one from another type of vehicle that would fit better around a 350.

 

If his wife is like mine, she is too used to power of modern brakes so won’t ever get past it.

 

If you have swing pedals you need to find a booster and master cylinder that will match your pedals

 

I ended up with disc brakes and power booster on my 71'. First on the D27 and then the D30. I had a bad experience once with drum brakes after completing the Rubicon. We were pretty much in water all weekend. When I got back to pavement the p side drum dried out first and a stop sign snuck up on me. I almost put it on the side and the pucker factor was huge. Anyway I used a 89 Cherokee power booster and master with both axles. Just make sure you use a thick mounting plate. I used 3/16". If you don't there is a ton of flex.