Dual diaphragm Upgrade part question.

[skidoo_j]

I'm wanting to get the easiest dual diaphragm upgrade.

 

I've read all about it in the past between here, madxj, naxja and a few other, but it seems most of my bookmarks are now dead. So I scrolled through the DIY forum here and couldnt find what I was looking for.

 

I know some have used a 97+ xj but then ended up having to pull the rod and rebuild it.

 

so people were using a 95/95 xj and adding the flat spot and enlarging the hole. (firewall spacer needed)

I also see people were using '00 wj. (no spacer needed?)

 

But IIRC one combination did not require relocation of the washer fluid bottle or modifying the firewall lip, but I can't seem to find the build/mod stating which one it was.

 

Anyone having insight as to which did not require modifications or relocation other then the push rod for the switch would be greatly appreciated.

 

 

I think I may have read where they used a dual diaphragm booster from one and a mc from a different one etc.

 

 

Thanks in advance.

[Zenobian_84]

so people were using a 95/95 xj and adding the flat spot and enlarging the hole. (firewall spacer needed)

I also see people were using '00 wj. (no spacer needed?)

 

Actually, you have them reveresed. If you use a WJ booster / MC, you have to enlarge the hole and add a spacer. On the 96 XJ (unsure if 95 is the same) it's a simple matter of installing it and bleeding it.

 

According to Don, the 96 is a plug and play deal, but I haven't seen anyone actually install one and give their 2 cents on it.

[HOrnbrod]

According to Don, the 96 is a plug and play deal, but I haven't seen anyone actually install one and give their 2 cents on it.

95-96 XJ swap is PnP for the 91-92 models. For PnP on a Renix you have to use the 91+ brake switch and splice some wires. I think if you retain the Renix switch you must grind the brake rod flat to make contact, but I haven't done a Renix model swap.

[skidoo_j]

According to Don, the 96 is a plug and play deal, but I haven't seen anyone actually install one and give their 2 cents on it.

95-96 XJ swap is PnP for the 91-92 models. For PnP on a Renix you have to use the 91+ brake switch and splice some wires. I think if you retain the Renix switch you must grind the brake rod flat to make contact, but I haven't done a Renix model swap.

 

So no BFH is needed to tweak the lip above the booster? does the 91 have the same washer fluid res?

[HOrnbrod]

So no BFH is needed to tweak the lip above the booster? does the 91 have the same washer fluid res?

If you use the aluminum spacer plate between the booster and firewall there is no need to touch the lip. I had to slide the old reservoir forward about 1/2" to avoid contact with the booster, easy. Then later I installed the 97+ XJ reservoir inside the left fender, so had lots of room. :D http://www.comancheclub.com/forums/viewtopic.php?f=9&t=5840

[skidoo_j]

So no BFH is needed to tweak the lip above the booster? does the 91 have the same washer fluid res?

If you use the aluminum spacer plate between the booster and firewall there is no need to touch the lip. I had to slide the old reservoir forward about 1/2" to avoid contact with the booster, easy. Then later I installed the 97+ XJ reservoir inside the left fender, so had lots of room. :D http://www.comancheclub.com/forums/viewtopic.php?f=9&t=5840

 

 

easier said then done on mine, I did an open conversion and used the 2.5 overflow bottle and I'm still using the factory air filter box. I'm not sure if I have 1/2" to move the washer fluid res.

 

 

 

Would someone who has done the 96 diaphragm conversion take a moment and measure from firewall to end of booster and to end of master cyc. So I could check for clearance.

[jeepcoma]

Here was my experience. No BFH needed. My reservoir moved about an inch forward so I did tap a new mounting hole for the screws, but that was it.

 

viewtopic.php?f=2&t=32143

[mjeff87]

easier said then done on mine, I did an open conversion and used the 2.5 overflow bottle and I'm still using the factory air filter box. I'm not sure if I have 1/2" to move the washer fluid res.

 

 

 

Would someone who has done the 96 diaphragm conversion take a moment and measure from firewall to end of booster and to end of master cyc. So I could check for clearance.

 

If you are using the 2.5 overflow bottle, you can relocate the washer resivoir to above the HVAC fan.....it fits there like a glove. Just drill two holes in the pinch seam and bolt it in:

 

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Jeff

[skidoo_j]

easier said then done on mine, I did an open conversion and used the 2.5 overflow bottle and I'm still using the factory air filter box. I'm not sure if I have 1/2" to move the washer fluid res.

 

 

 

Would someone who has done the 96 diaphragm conversion take a moment and measure from firewall to end of booster and to end of master cyc. So I could check for clearance.

 

If you are using the 2.5 overflow bottle, you can relocate the washer resivoir to above the HVAC fan.....it fits there like a glove. Just drill two holes in the pinch seam and bolt it in:

 

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Jeff

 

 

did you change out the pedal assembly in the cab too, or did you space out the diaphragm to make the push rod the same length?

[mjeff87]

I screwed up the "grinding down the end of the rod" part and couldn't get the old brake light switch to work, so I ended up swapping in the whole pedal assembly from the donor XJ I got the booster from. Quite the PITA doing it solo, having a second pair of hands would have really helped, but I got it done.

 

My brake and clutch pedals are off about 1" in height, but it really doesn't bother me.

 

Jeff

 

edit: I spliced the new brake light contact switch into the wiring of the old switch, you need the pink and white wires on the new switch (I just cut off the other wires):

 

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[Blue88Comanche]

i don't remember if i used the 97+ XJ or the WJ booster and MC but i had to enlarge the hole in the brake rod and gring a flat edge on it. i don't think i had to hammer the lip by the booster when i put the brakes in but i did hammer on it later when i was replacing the clutch line.

 

here is my current setup on my Blue MJ (4.0 / AX-15).

 

 

 

 

[skidoo_j]

i don't remember if i used the 97+ XJ or the WJ booster and MC but i had to enlarge the hole in the brake rod and gring a flat edge on it. i don't think i had to hammer the lip by the booster when i put the brakes in but i did hammer on it later when i was replacing the clutch line.

 

 

Looks to be from the Wj based on what you did, and the appearance. the 97 plus requires the rod to be replaced based on my readings. I noticed in your photos that the washer bottle is not attached, were you able to attach it back in the factory location?

 

I think I'm set to pick up a wj set up, seems best option for pre 90's. as it's only 3/16" longer rod so all is needed is minimal spacer, drilled rod, ground flat and good to go. Still in air if washer bottle needs relocated.

 

the 95-96 is a direct bolt on with 91+ un-sure of spacers as i didn't research it much. I've read that the 95-96 rod is actually 3/4" longer then pre 90 so it's advised to space it or cut and weld.

 

 

Thanks everyone for your help and pictures. It's really helpful. I like when we can gather information all in one thread rather then across 20.

[MJCARENA]

I put a 95/96 XJ booster in my 89 XJ. Drilled the hole bigger and ground the rod end flat (grind a little off at a time till it matches the original thickness from the hole to the flat spot, to much and the brake switch won't work right,don't ask how I know this.) Moved the bottle a little forward and ran new brake lines from the new master to the original prop valve. Also used the spacer that came with it, no bending of the lip needed. Very easy mod. Just working under the dash wasn't much fun. Must be getting old.

[nhrocker]

I used a '96 junkyard booster to upgrade my '90.

 

I did use the spacer, so I didn't have to bend the lip. The washer bottle was relocated further forward. I made the stock pedal and brake switch work by cutting the end off my old and new rods (after carefully measuring to get the length right) and welding the end of the stock rod onto the '96 setup. Pedal is the proper height and brake switch works better than before after cleaning it while it was out.

[ratrapp]

the 95-96 is definitly the easiest way to go.i didn't change any brake rod or such.i got the complete booster/master cylinder, valve, lines and spacer from the salvage yard for $40.all i had to do was slightly grind the rod for the renix brake light switch to work.i had already moved the wiper jug in the fender using the 97-01 ckerokee parts.

[skidoo_j]

How thick of a spacer are you guys using on a 95-96 booster into a <89???? According to the specifications the push rod on a 95 is 5.75" where the <89 rod is 5". This measurement is from booster to center of push rod. The stock spacer only appears to be 1/2" at best. Am i missing something, wouldn't that mean that your brake pedal is pressed in 1/4" at all times?

 

Or is there enough slack in the pedal assembly to allow it to just sit 1/4" further from the floor board making the brake and clutch offset?

 

I could see the 95-96 being a benefit because you don't have to screw with the brake line adapters for the sizes, however still relocating the washer bottle is probably a no go for me. Because I converted to the open system with the aluminum purge tank and am using a 2.5 overflow see my pic. If a 97 washer bottle was available around me it maybe different. I'd much rather buy a 95-96 as a reman booster and new master would be about 130 vs 240.

 

Another question, when everyone did the booster upgrade did anyone keep the weight proportioning valve?

 

 

 

Here's a pic from jpmagazine. left is 89mj middle 95xj right 00wj-- you can see the push rod length differences.

[ratrapp]

i ditched my load valve at the same time i did the booster upgrade.

[skidoo_j]

I ended up buying the wj booster/ master.   Here are some pics.   I made my spacer out of 1/4 aluminum.  The lip on the fire wall did have to be bent up some for clearance, and I did have to enlarge the whole on the push rod and ground a flat spot for the brake switch.   Nothing had to be relocated.  I did do a lot of research prior to my purchases.   The 95/96 is a direct bolt for 91+. (no enlarging or griding for switch).   If you get the pedal assembly from a 91+ it should bolt into pre 90 so you can eliminate that as an option.   Another option i did stumble across but didnt explore was a booster from a 2000 wrangler.  The push rod appears identical to that of our renix era booster, however I couldnt find the lenghts of the wranglers rod, so it maybe a direct bolt on.    

 

For the brake lines I purchased a 3' piece of tube with bubble flare with m10 ends then picked up some m12 ends.   cut to length and double flared the other.  It was about half the price doing it this way, and they were the lengths i needed with out adapters. 

 

I've been debating on writing a DIY on this and cover all aspects so we can consolidate all the booster questions that show up all over.    

 

 

 

[jpnjim]

I used a 2001 XJ Master cylinder/booster & pedal assemblies in my 88' Renix 4.0L 5spd.

I had to use the 88' clutch pedal with the 2001 hanger bracket,

since the 01' clutch pedal arm wanted to be right where the 88' fuse box is.

 

Clutch pedal grabs a little low now (with the 01' clutch cylinder),

probably end up fixing that before it drives me crazy :)

[cruiser54]

I ended up buying the wj booster/ master.   Here are some pics.   I made my spacer out of 1/4 aluminum.  The lip on the fire wall did have to be bent up some for clearance, and I did have to enlarge the whole on the push rod and ground a flat spot for the brake switch.   Nothing had to be relocated.  I did do a lot of research prior to my purchases.   The 95/96 is a direct bolt for 91+. (no enlarging or griding for switch).   If you get the pedal assembly from a 91+ it should bolt into pre 90 so you can eliminate that as an option.   Another option i did stumble across but didnt explore was a booster from a 2000 wrangler.  The push rod appears identical to that of our renix era booster, however I couldnt find the lenghts of the wranglers rod, so it maybe a direct bolt on.    

 

For the brake lines I purchased a 3' piece of tube with bubble flare with m10 ends then picked up some m12 ends.   cut to length and double flared the other.  It was about half the price doing it this way, and they were the lengths i needed with out adapters. 

 

I've been debating on writing a DIY on this and cover all aspects so we can consolidate all the booster questions that show up all over.    

 

 

 

What year WJ?

[Dillithium]

I'd be happy to make a DIY guide for the WJ conversion, but I don't know how many people would benefit from it since I'll be putting it in an 86. I have yet to do the conversion, but as soon as I pass state inspection it's number one on my list. I already have it laying around to do it, I got it from a 2000 WJ with the 4.7.

[xjrev10]

I'd be happy to make a DIY guide for the WJ conversion, but I don't know how many people would benefit from it since I'll be putting it in an 86. I have yet to do the conversion, but as soon as I pass state inspection it's number one on my list. I already have it laying around to do it, I got it from a 2000 WJ with the 4.7.

Do it. I'm swapping one soon into mine.

[KYMJ]

I'm in the middle of doing this  right now. My stocker has been leaking air, and I'm off work all week, so I figured it was a good time to do this. I have a booster from an 01 WJ and a booster from an 06 XJ. The XJ will bolt up w/o modifying the firewall, the WJ will not(I'm using the 1/4 spacer). I believe I'll be able to keep the washer bottle with the WJ, don't think it's possible with the XJ, it's longer and tapered to accommodate the firewall. The WJ fits much better. The XJ has double flare lines which may help with the plumbing, however I haven't gotten to that yet. I'm having problems with the brake switch. CRITICAL, I took off too much and will have to add some metal and start over. I measured the distances with a micrometer and they're the same but no worky. Sucks. I've already modified the firewall and that was very easy, I simply pried it up with vice grips and it doesn't have that "beat up" look to it. So, as soon as I can get the stoplights working I'll get to the plumbing. I'm also going to plumb in an adjustable prop valve to rear wheels as my original blew out in a panic stop years ago and I removed it. I'm tired of my rear wheels locking up in the rain. Anyway, it's turning into a multi day job and if I don't have any better luck, I'll order a rebuilt stocker and abandon the project. As far as plumbing goes, I found some adapters for bubble flares to double flares and might use them if theres enough room between m/c and washer bottle, I'm kinda doubting it, But not there yet. If you get the switch deal worked out(pain in the butt), seems like all will be fine with the WJ booster.

[KYMJ]

Got the stoplights working and m/c plumbed using the 01WJ lines, double flared on the MJ side. Will be a couple of days before I can try it out. I'm waiting on the adj. prop valve and I found some leaky brake lines on the rear, the time to fix those.

[RockMJ]

This is all good to know. I was planning on ordering the NOS brake booster from Team Cherokee for the 95/96 XJ. Drahcir has done this mod on several of his Jeeps and I have yet to attempt it. I hear a lot of horror stories about grinding too much off the arm for the brake light switch. Should hopefully be ordering up the NOS unit soon and getting the brakes done. It is one of my top priorities right now because my Jeep does not stop, even with a new single diaphragm booster. Thanks for all the helpful posts.

 

RockMJ