Author Topic: YJ Brake Upgrade  (Read 5767 times)

Offline kirksjeep

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YJ Brake Upgrade
« on: January 12, 2012, 03:57:15 PM »
Since us YJ guys never had an option for a D44, we have to upgrade to the ford 8.8 rear.  With the 8.8 you get disc brakes, which help a little at stopping the bigger tires, but the YJ single diaphram brake booster is a limiting factor.  There are few upgrades out there such at using parts for 70's fords or finding a set up out of a 95 (only year that works, very hard to find and expensive) master cylinder and  brake booster.  I came across the link below that uses a set up out of a TJ.  Now I just need to get one off of Ebay (average price $45).

http://www.jeepforum.com/forum/f12/06-tj-booster-mc-my-yj-1177891/

1992 YJ Sahara, 4.5 Rubicon Express ED Lift, 35" BFG MT, Custom Bumpers, SYE/CV Drive Shaft, OBA, Ford 8.8 rear, 4.10 gears, tie rod flip, 1"MML/BL
2002 KJ Liberty, 2" Lift, 31" tires/DD
2002 F-150 Harley Davidson 5.4L SC
2013 Explorer Sport
2006 Harley Road King Classic
1988 Honda Hawk GT

Offline Bill3753

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Re: YJ Brake Upgrade
« Reply #1 on: January 12, 2012, 09:35:04 PM »
Sinister Fab makes this for a TJ.  Maybe it could work on YJ's too?

http://www.sinisterfabworks.com/shop/item.aspx?itemid=57

"This is Made to Fit perfect onto the Power brake booster plunger to make the dodge 99-01 master cylinders work on your Jeep TJ to upgrade your brake system for one ton style calipers."
04 TJ, HP60, 14 Bolt, 5.13's, linked, locked, on 38's and (still) in the works.

Offline kirksjeep

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Re: YJ Brake Upgrade
« Reply #2 on: January 13, 2012, 04:49:10 AM »
I just picked up a brake booster, master cylinder and proportioning valve from an 04 TJ on Ebay for $40 (and free shiping).   ;)
1992 YJ Sahara, 4.5 Rubicon Express ED Lift, 35" BFG MT, Custom Bumpers, SYE/CV Drive Shaft, OBA, Ford 8.8 rear, 4.10 gears, tie rod flip, 1"MML/BL
2002 KJ Liberty, 2" Lift, 31" tires/DD
2002 F-150 Harley Davidson 5.4L SC
2013 Explorer Sport
2006 Harley Road King Classic
1988 Honda Hawk GT

Offline gearhead1985B

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Re: YJ Brake Upgrade
« Reply #3 on: January 13, 2012, 08:39:53 AM »
k with my pos i run the stock yj single diaphram booster a a 69 corvette master 89 waggy calipers on all 4 corners with an adjustable propotioning valve to for the rear and all 3/16th line every where it stops on a dime

i did have to jack with the adjusting rod to make them stop as good as they do i went out 2 or 3 full turns
"If you can read this, Thank a Teacher, if you can read it in English, thank a SOLDIER"

https://www.masterpull.com/Index.aspx
http://www.taboocustoms.com/

Offline kirksjeep

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Re: YJ Brake Upgrade
« Reply #4 on: January 29, 2012, 03:19:18 AM »
My parts finnaly arrived today.  Too bad I have duty tomorrow, and I in a few days, I leave for a few weeks. :(  I am stocking up parts for a weekend of wrenching when I get some time.  On the to do sometime list:
Install the Chromo D30 shafts that have been sitting in a box for over a year
Install the Power Steering Cooler
Fix my Onboard air
and now add the Brake Booster and Master Cylinder
1992 YJ Sahara, 4.5 Rubicon Express ED Lift, 35" BFG MT, Custom Bumpers, SYE/CV Drive Shaft, OBA, Ford 8.8 rear, 4.10 gears, tie rod flip, 1"MML/BL
2002 KJ Liberty, 2" Lift, 31" tires/DD
2002 F-150 Harley Davidson 5.4L SC
2013 Explorer Sport
2006 Harley Road King Classic
1988 Honda Hawk GT

Offline kirksjeep

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Re: YJ Brake Upgrade
« Reply #5 on: August 05, 2012, 07:12:29 PM »
So based on my list of "To Do" items above, this was my last one.  I will post this up incase anyone in the future wants to look up this topic.  I followed most of the "How to" from the link in the first post with the following changes:

1.  The used TJ brake booster/master cylinder combo didn't come with any of the nuts to bolt it to the firewall or to bolt them together.  A quick trip to Home Depot with the brake booster in hand and I was set.
2.  I used a 2" grade 8 bolt for the adjustment part.  I cut the head of the bolt off and used a grinding wheel to make a vertical notch about 3/8" deep.  I slid the end of the brake booster rod (previosly cut off) into the notch and made it so it was a tight fit (i.e took some light taps with the hammer to get it in.).  When the welding was done it gave more area to weld and came out looking a lot cleaner.
3.  The adjustement portion of the install was not very well explained.  In short, I got it close and noticed the brake lights were on, so I adjusted the rod lenth until the brake lights went out.  I also just used a standard nut, not a nyloc nut since I can't see how it come come loose, and to make adjustments with the assembly installed is hard enough with the tight space under the dash. 
4.  I re-used the YJ brake lines from the proportioning valve to the master cylinder.  I pulled them off, cut the ends off that go to the master cylinder and installed the TJ fittings.  I have a double flare tool, but these lines needed the ends to be convex instead of concave.  I did a double flare and then put the fitting in the vice and gently used a body hammer to bend the lip and make the right shape.  I then used a file to smooth any rough areas and it came out looking ok.  I re-used the YJ proportioning valve so I didn't have to take apart more brake lines.  With a little flexing of the lines it all worked out.

The result: WOW!!!! The first trip around the block I locked up all four tires on accident since I wasn't used to the power. A big difference, that I should have done a long time ago.
1992 YJ Sahara, 4.5 Rubicon Express ED Lift, 35" BFG MT, Custom Bumpers, SYE/CV Drive Shaft, OBA, Ford 8.8 rear, 4.10 gears, tie rod flip, 1"MML/BL
2002 KJ Liberty, 2" Lift, 31" tires/DD
2002 F-150 Harley Davidson 5.4L SC
2013 Explorer Sport
2006 Harley Road King Classic
1988 Honda Hawk GT