YJ Brake Upgrade

cj777

cj777

Well-Known Member
Joined
Mar 22, 2005
Location
Durham, NC
I've got a 91 YJ with a Dana 60 front and 14 bolt rear. Both the front and rear axles are running 3/4 ton Chevy calipers to fit my 15" wheels. I'm currently running the stock master cylinder and power booster. The power booster has a vacuum leak, and I'm using it as an excuse to upgrade the very poor braking system. So I'm looking for options of what master cylinder and power booster to replace these with. I was leaning towards Yager's JB7 swap http://www.nc4x4.com/forum/threads/jeep-update-v6-3-jb7-brake-swap.12699/
But am open to suggestions, e-350, grand marquis, corvette, etc. What are the pros and cons of each, or what's worked for you?
 
The one I'm using and have used for years is the Dodge 15-3500 master cylinder. Its a direct bolt in aside from having to replace the adjuster screw with one a good inch longer to seat plush inside the booster cup. You'll need about 5/8" over stock roughly but it'll take some mockup. The bore is quite larger than the stock TJ mc and the braking force will improve greatly. In the few ive done, some ended up having a slight lag from stagnant to 1/4 pedal but thereafter it kicks in with a vengeance, easily locking up 42s on the pavement.
I'll also add that I'm running G20 calipers on the rear and single piston GM 1 tons on the front.
 
XJsavage said:
The one I'm using and have used for years is the Dodge 15-3500 master cylinder. Its a direct bolt in aside from having to replace the adjuster screw with one a good inch longer to seat plush inside the booster cup. You'll need about 5/8" over stock roughly but it'll take some mockup. The bore is quite larger than the stock TJ mc and the braking force will improve greatly. In the few ive done, some ended up having a slight lag from stagnant to 1/4 pedal but thereafter it kicks in with a vengeance, easily locking up 42s on the pavement.
I'll also add that I'm running G20 calipers on the rear and single piston GM 1 tons on the front.
Click to expand...
So you're using a stock TJ booster? I think I remember reading on Pirate that a TJ booster won't clear a CJ hood.
 
Yes, stock TJ booster. If I had to upgrade the booster I'd probably use a dodge 1500 style just to keep everything uniform. I don't really know much about boosters as far as bolt patterns and heights and such between the big 3, however.
 
I'm using stock 90 yj booster and 69 Camaro master cylinder.

The 69 Camaro one has equal reservoirs. It's all cast iron. Be careful as the front port is for front brakes and the rear port for rear brakes unlike all newer m/c's. I had to make a new adjustment bolt for the pedal rod, not too hard to do. It was 1/4 or so longer than stock. This really allowed me to get the pedal how I want it.

Beat of all this m/c fits a large majority of vehicles and is in stock at almost all part stores. I checked several to find something that is not special order. I did have to grind slightly to fit all the way back against the booster.

Also the lines come off the driver side so it is much easier to work on than ford/jeep etc that the lines come off on the pass side.

Best brakes I have ever had, will easily lock up 42's if I get on the pedal hard. Chevy 60 with stock calipers up front and 14 bolt with 1/2 ton calipers in rear.
 
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