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Brake booster swap and brake switch 89 and ?

Ecomike

NAXJA# 2091
NAXJA Member
Location
MilkyWay Galaxy
I need some help on a thread I already started in OEM. It seems I inherited a non 89 OEM booster in the 89 XJ I have. I know the Mod people have done a lot of brake custom upgrades, so maybe you can help me figure this out. Here is the link to my OEM post, and all the details:

http://www.naxja.org/forum/showthread.php?t=1055610&highlight=brake

Is the sleeve diameter smaller, and brake switch clearance larger in the later years than 89? If so which year changed? Why would some one use a later year booster that looks, size wise like the 89 booster? I am hoping I can figure out what they used, and then order that year brake switch to solve my problem.
 
hope this helps:
The WJ booster went south on me, so I replaced them with 95-96 XJ units. The old style brake light switch requires grinding on the end of the booster push rod in order to fit. :thumbdown: I solved that with an HO cruise control bracket and a simple painless wiring switch.
SANY3326.jpg

The switch...
SANY2803.jpg


I got the idea from this pic I found over on ComancheClub...
100_2571-1.jpg

I found the bracket on an unknown year model. I assumed it's was an HO model. All of the Renix models I looked at had an extra wire running to the booster rod mounted brake switch instead of this type bracket. It's off an auto trans model as well. It did have to be slightly modded to fit my manual pedal assembly...
100_2571-1-1.jpg

...I ground off this corner and notched the opposite side corner. I also moved the switch in the opposite hole shown in the pic. I moved the mounting insert to the next hole as well. It's a little easier to see in this pic with it installed.
SANY3326a.jpg

With the slight grinding I did the bracket slid on the pedal assembly and even lined up with an existing hole in the pedal assembly. The switch is this painless model is this one. Painless Wiring 80172 - Painless Performance Push Button Brake Light Switches - Overview - SummitRacing.com it's cheap, and it can even be ordered through AutoZone.
I did have to tweak the bracket down a little to make good contact and maintain some adjustment with the switch. Then all you do is cut off the old plug and solder on a couple of female spade connectors.

http://www.jeepforum.com/forum/f22/my-88-comanche-886068/index23.html#post10091257
 
Thanks for the links, lots of answers in both. I am left with a question, did anyone bother to see if the 95-97 brake switches and sleeves would solve the problem in an older jeep upgrade?

For now I am assuming the BB I have is a later year, but it physically looks like an 89, not a double diaphragm near as I can tell, so I am still puzzled as to how and why it was shoved in 89. Looks too new to be a JY pull, unless it was nearly new when when the xj was junked. I will take a closer look tomorrow.
 
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I ended up going back to just the 3/8" OD bolt, no sleeve, the stock switch, and some large diameter OD brass washers to fill the gap left by not using the sleeve and plastic spacers. I did not drill, grind, cut or weld anything...etc.

I got the bolt nut set just right, then put on the lock nut, so it is not too tight or too loose (took several tries), and I added a piece of scrap rubber and duck tape under the switch, wrapped around the brake peddle arm, just below the brake switch so it can not be knocked down out of proper position.

It is working perfectly now. Thanks for all the feedback.

I did look for a later year switch, but non were a match. All the later year switches are more like the white upper switch that is threaded on the end.
 
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