11-inch Brake Upgrade

Keeping the Original Look

Jeff Heidman posted this on the old CJ-3B Bulletin Board, and people continue to discover this great tip for upgrading a Jeep from 9-inch to 11-inch brakes to provide more stopping power, while still resembling the original equipment.

S lineJeff: "When upgrading to 11" self-energizing brakes on your front axle, and want to keep the original look to your install (hose guards and "S" hoses), order wheel cylinders for a 1985 Ford F350 with dually wheels -- they are the same 1-1/8" diameter cylinder as the factory CJ-5, but have the inverted-flare straight connection that the original 9" brakes came with. A new "S" line will have to be modified to connect with the new wheel cylinder. I used the flex lines on my installation, but may swap out to keep the original look."

9-inch and 11-inch"Old brakes versus the new! The part numbers are: left side P/N W35325, right side P/N W35326. Both are DRW cylinders (dual rear wheels.) Just ordered another set from rockauto.com for cheap!"

Complete"These are pictures of the install on a John Maldino's CJ-2A that is currently being restored."

See also the new and old brake drums (130K JPEG).

Daryl in Washington: "I like the look of the originals with the S lines. Anytime we can make brakes stop the load better while keeping the original look, seems like a win-win situation."

Bob: "Very nice. I managed to get the original "S" lines onto my 11" brake conversion and use the guards as well. Looks a lot better."

oldtime: "Nice tip. I like it. I like those Monroe shocks too. Those are the old #1004 shocks. They are not gas charged. I guess the next big debate is... early "S tube" style brake lines with hose gaurds, vs. the later long frame-mounted hoses.

S line and Z line"A while back I built and installed some 10" Wagner brakes that were removed from a Dauntless CJ. They were placed onto a 3B having the early-type brake tube configuration (short hose at cylinder).

"The 10" Wagners are very much like the the 11" Bendix CJ brakes concerning the cylinder port angle. I found that I was readily able to use the hose guards via using stock CJ "Z" tubes in place of earlier "S" tubes. When applicable I much prefer the "Z" tubes in lieu of the occasionally uncooperative "S" tubes."

From the Willys Jeep Parts website:





$ 4.50 EA.




The Upgrade

Rock-EttAs of 2015, Willys Jeep Parts in Arizona is offering a four-wheel 11" brake upgrade kit "entirely comprised of Willys OEM and replacement parts" for $1100.50. A little pricier than these Rock-Ett reconditioned Mercury brakes from Dana axles, advertised in 1965 (right).

There are a number of other vehicles, typically from the 1970's, that have been used as donors for this conversion (see further down this page.)

Jon Paulsen described installing an 11-inch brake kit available in the late 1990's: "You get all new parts including the backing plates and new rubber hoses to go from the pre-installed brake cylinders to the hard line on the axle. You don't need to do any assembly, because everything is already assembled to the new backing plate, just bolt it up, hook up the lines and bleed 'em. Count on a weekend, but well worth the effort.

"I guess you can also go for bigger brakes from newer Jeeps, but you want the 11" ones to do much good, and you'll likely need to do a lot of work to used ones, if you can find them.

"When I put them on, I also could only afford 1 axle. I still have the small ones on the rear, and it works fine. Before, I could never get the front ones to lock on road, even with good pads and fully adjusted. Now they seem well balanced. The front brakes will skid when braking hard, and the rear will occasionally make some noise too. The rear brakes don't completely lock up.

"Caution: You should thoroughly test any brake work before street operation. Modifications to brakes need even more thorough testing. The results you get may differ due to different tires, weight distribution, and other factors. It is very important not to end up with a braking system which causes the rear wheels to lock up during hard braking. A proportioning valve may need to be incorporated to adjust the balance and avoid rear wheel lock-up, especially if upgrading both axles. Be sure to observe all precautions and follow all instructions supplied with the 11" brake kit.

"If you can only do one end, front is better because the front provides a much larger percentage of the stopping power. This is because most vehicles are "front heavy" to begin with (from engine weight), and as you apply the brakes, even more weight is transferred to the front. The harder you brake, the more weight is transferred. This makes it very easy for rear brakes to lock up and very difficult for the front to lock. That's why they often put discs on front, drums on rear. Newer vehicles have proportioning valves to send more pressure to the front, where it's needed, but my 58 lacks the valve.

9"The 11-inch brakes offer more braking power in two ways. More surface area 11x2 in = 22 sq in. Also, they have a larger slave cylinder which generates more 'mechanical advantage'.

"You've got to pull the backing plate which means, pull the tire, drum, locking hub, spindle, wheel bearings. Good stuff to know how to do anyway. See Brake Drum and Wheel Hub Removal. You need the giant socket to remove the big nuts on the spindle (about US$10 to 12). While you're in that deep, you might want to inspect and/or adjust the king pin bearings -- fairly simple if you know how. Chiltons '45 to '74 CJ's or whatever they call it covers all this (you need a $5.00 spring scale -- you have to measure 14 lbs. if I remember). Haynes says to go to the dealer for king pins. Our Lafayette dealer doesn't even know what a CJ-3B is. Thought mine was an orange army Jeep.

"Anyway, you DON'T have to pull all the pads and springs and stuff off the backing plate, or assemble that stuff on the new... it all comes in one nice chunk. I did mine on a weekend including new cylinders for rear, new tubing, and I rebuilt the master cylinder. It was a looooooong weekend! Lonely! Good idea to do in winter, so you don't miss any sunny days with your beloved Jeep!"

Potential Problems

After purchasing the parts to perform an 11" brake upgrade, Todd Marquart noticed a potential problem. "I bought the full backing plate assemblies to convert my front brakes to 11". The 11" drums do not have the 3 holes for the screws that attach the drum to the hub. I'm wondering if I should drill the holes or simply leave them out, allowing the lug nuts to hold the drum against the hub."

Bruce responded: "Most modern vehicles with drum brakes don't use any screws, rivets, etc. to hold the drums on. I don't think they need them. Where can it go? An old-timer once told me the only reason they were there was to keep the drums from falling off on the assembly line."

Ed Wilson agreed: "The 11" brake package I purchased several years ago does NOT use the screws to secure the drums and works just fine."

Todd later reported: "I had a rather long trek installing 11" brakes on my '56 3B. It required me to replace the driver's side steering knuckle due to stripped threads. I bought a new steering knuckle and installed it.

"First was the issue of how to hook up the new 11" brakes. The hard "S lines" did not fit and needed longer threaded fittings for the larger wheel cylinders. After talking with the mechanics, I purchased longer rubber lines and eliminated the "S lines." This required removing the shield that is mounted to the kingpin retainer. At this point, the first problem showed up. The bolts that hold this shield on are longer than the other bolts, and when tightened down, will rub and score the inner portion of the steering knuckle. I put extra lock washers to fix this, but not before scoring the metal.

"Now all I had to do was put in the tie rod end and torque it down to 60 ft-lbs and I'd be done. When I put on the castle nut and torqued it to spec, it had pulled the tie rod end up until it ran out of threaded stud and then stripped the stud and castle nut. I bought a new tie rod end thinking that was the problem but the new one fit the same. I am now looking at trying a new steering knuckle. I have the tie rod installed, but not torqued to spec on the defective knuckle. The brakes work great and I have all of the original equipment if I decide to restore her."

Joel Kamunen has a caution for the few people who may have stock 15" wheels rather than the usual 16" stock wheels: "One thing that I overlooked was the wheels. After my 11" brakes were installed, I found out that my stock 15" rims wouldn't fit over the new larger brake drums, so I had to get new white spoke wheels. For anybody doing this conversion, they might want to plan ahead if they have the 15" wheels."

Tim mentioned: "I have, in the past, run 15-inch white spoked rims and also 15-inch Ford 4x4 Pickup rims. Both fit without interference."

Glenn Houston added: "The original 15-inch Jeep wheels will not fit, but both Ford and Dodge 15-inch will fit, at least all that I have tried off pickups will."

Russ W. posted: "15 inch will not fit if you use the heaver cast drums or fin type. I finally found ones that would fit, off a Wagoneer. They are rather thin walled. It is a close fit."

Parts Donors

Joel Kamunen had these comments about finding used parts: "The backing plates for the 11" brake conversion are becoming harder to find. So far I have found that the following vehicles use the desired parts for the conversion: 1972-1974 Jeep CJ, 1967-1970 Jeep truck/ Wagoneer, some DJ Jeeps, some Jeepster Commandos, International Scouts using Dana axles. We will probably have to dig through the junk yards for future conversions."

Dan Koozer added: "Ford pickup ('56-'65?) half-ton brakes will bolt up with the use of a simple easy to make adapter. Novak used to sell the plans for this conversion."

Jim Sammons also believes in checking the wrecker first: "People can say what they want about scrounging but I have found many a good part in the junk yard. Most people that don't scrounge must have lots of money. Just about every junk yard I visit is very reasonable. Try any vehicle with a Dana 44 rear axle, such as IH Scout, Ford pickups, and mail Jeeps. I am fixing to start scrounging for larger front and rear brakes myself. I have in mind for the front brakes, the brakes off of a 2-wheel drive mail Jeep or off the front of a Scout. I know the ones off the Scout will work but want to try the ones off the mail Jeep because they are larger. I have already found out that disc brakes from a Dana 44 front end will not work on the Dana 27 axle. Good luck scrounging."

Brian suggested another donor: "I got my brakes from a '73 or '74 Wagoneer. $100 at local junk yard. Would have been less but they insisted that in order to use the backer plate I needed the hub also! Drums were a mismatch, so I had to replace, but still cheaper than the $500 quoted from a local 4 wheel shop."

Adam Sparks: "For my 1962 CJ-5 I got brakes from a '74 CJ-5, front and rear. Had to drill the backing plate for the rear drums since the holes didn't quite line up -- no biggie though, plenty of metal there to drill in and have plenty of strength left over. Front was a straightforward swap. Pretty easy -- now I have self adjusting drums all the way around. I paid $400 for all four brakes and then bought new shoes for the front and new wheel cylinders."

Joel Kamunen: "I wasn't happy with Four Wheel Parts Wholesalers either, but now that I have my brakes installed, I'm happy with the improvement. The new 11" brake sets are imported and only so many come into the country at a time. Using a donor vehicle is your next best hope. When I installed my 11" brake set I noticed that the new front brake lines were quite long, but I figured that was for suspension articulation."

Ken Reed: "I just completed the swap in 4 hours and everything off a '73 Wagoneer worked perfect. I did use the brake hoses from the Willys as the Wagoneer's were way too long."

Note: steering and brakes on your vehicle are critical to life safety. The information on this page is general in nature; if you are uncertain where your problem lies or how to correct it, get professional advice.

Thanks to Jeff, Jon and the other contributors. -- Derek Redmond

Return to the CJ-3B Tech Tips page.

FacebookVisit CJ3B.info on Facebook.

CJ3B Home | Contents | Search | Links | 3A and 3B Community

Last updated 31 December 2015 by Derek Redmond redmond@cj3b.info
All content not credited and previously copyright, is copyright Derek Redmond