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booster swap only?

ehall

NAXJA Member
NAXJA Member
I got a booster and master cylinder from a 95 part-out with the intention of replacing the stock junk in my 91. However I have since determined that replacing the master cylinder will likely need to be accompanied by a replacement of all the hard lines as well, so I'm not eager to do that right now. Can I swap the booster only? I assume so but wanted to ask first. Also my washer fluid reservoir seems like it's packed in pretty close over there, will I need to relocate it to do this?
 
I put on the WJ booster and did not change any lines. Still stopping fine. I did have to do some adapting of the lines to the master cylinder because of metric issues, but those were just 6 inch adapter lines, the main brake lines are the stock ones. Mine is a 1991.
 
I did the booster swap in my 89 and still haven't figured out a way to re mount my asher fluid bottle. But i was an idiot when i bent my lines and didn't bed them tight enough or else i could still have my washer fluid bottle. The booster and mc fit fine, it's the hard lines that could give you problems as far as clearance.
 
I have yet to confirm this, but I am given to believe it's not a direct swap (old M/cyl to newer booster.)

I'm sure I'll be working on this at some point - I greatly prefer the one-piece iron cylinder over the two-piece aluminum-and-plastic job, but I'm just funny that way...
 
can't comment on the booster/master compatibility, but I swapped in the whole sheebang on my MJ and had clearance issues with the washer bottle. I moved it over to the passenger side firewall, right above the HVAC blower motor (where the overflow bottle would be on a closed system cooling system). It fits like a glove there.

Jeff

31LTs009.jpg
 
I got a booster and master cylinder from a 95 part-out with the intention of replacing the stock junk in my 91. However I have since determined that replacing the master cylinder will likely need to be accompanied by a replacement of all the hard lines as well, so I'm not eager to do that right now. Can I swap the booster only? I assume so but wanted to ask first. Also my washer fluid reservoir seems like it's packed in pretty close over there, will I need to relocate it to do this?

i dont see why bending and flaring 2 lines is an issue to not do the master swap.

i did the wj booster/master swap on my 89 and had no issues with clearance or bending/flaring.

buy 1, 3 foot section of brake line with the ends flared and with the connectors. cut the line in half, bend the lines to fit, double flare the 1 end of each. i practiced double flaring on some lines before i did on the one i bent to fit. i just cant see the flaring and bending to stop you from the master swap.
 
I got a booster and master cylinder from a 95 part-out with the intention of replacing the stock junk in my 91. However I have since determined that replacing the master cylinder will likely need to be accompanied by a replacement of all the hard lines as well, so I'm not eager to do that right now. Can I swap the booster only? I assume so but wanted to ask first. Also my washer fluid reservoir seems like it's packed in pretty close over there, will I need to relocate it to do this?

Do yourself a favor and do the lines at the same time,I did the swap one evening after work. The lines were simple to whip up.On my 89 the washer bottle stayed put, there was enough room. The old master uses a different pushrod than the upgrade one so I'm thinking it will not work
 
The bolt holes to hold the mc to the booster are the same 3.25" but I cannot tell about the orifice... it may be a different size or use a different o-ring.

The booster drum is about 1.5" deeper, which will push the front of the stock MC right up to the back of the airbox, and will push the front of the drum right up against the washer reservoir. Everything should fit, maybe as much as .25" clearance after loosening hardware and pinching stuff around.
 
Just remembered about this so I went and checked, the orifice is the same diameter and the pushrod looks the same as well, however the pushrod is down inside the booster on the 95/96 setup and is sticking out the orifice on the 91 stock booster. So they won't mate unless the rod is replaced with one that is longer, probably the same 1.5"
 
One of the cool things about the swap is that the new m/c booster combination is the same length as the old one, so it all fits. The washer bottle might need to be slightly moved depending on the year.
 
I have the MC just didn't want to mess with the lines since I might replace the whole shebang later (JK axles, WJ booster/mc) and am not in the mood to do it all twice. I was really hoping the booster would swap by itself, so I would not have to mess with the hydraulics. I will see if the lines will come free, if they fight any I will probably pass
 
I have the MC just didn't want to mess with the lines since I might replace the whole shebang later (JK axles, WJ booster/mc) and am not in the mood to do it all twice. I was really hoping the booster would swap by itself, so I would not have to mess with the hydraulics. I will see if the lines will come free, if they fight any I will probably pass

My lines came loose without a fight as did everything else. i am almost done with the swap. I need to make up the lines and extend the connections for the brake sensor and both washer pumps.
 
Picked up a '95 XJ dual diaphram booster with MC, proportioning valve and lines and local pick and pull...lucky, find minimal cost. Now just need to do the fit. Am concerned about brake light switch...anyone know if Matt Homan has a new e-mail address, the one from madxj is out of service. would love to know details of how he (or others who did this successfully) made brake light switch work on this mod.

thanls!

Vinnie
1990 XJ Limited
 
Well, when you find out how to make the brake light switch work let me know. I just finished my swap and followed the write-ups to the letter and now no brake lights. The switch is working because I can pull down or push up on the switch and the lights come on. For some reason the switch will not work with the pedal.

The swap has gone well other than this little glitch.
 
For some reason the switch will not work with the pedal.

The swap has gone well other than this little glitch.

Same deal with my swap, but I think I ground too much off the rod end for the switch to make contact. I ended up going back to the junkyard to the XJ I got the booster from and swapped the entire pedal assembly into mine. Used the newer version contact switch, spliced in the pink and white wires to my old brake light wires. Set the depth on the new switch, and walahhh....brake lights :)

Jeff
 
Same deal with my swap, but I think I ground too much off the rod end for the switch to make contact. I ended up going back to the junkyard to the XJ I got the booster from and swapped the entire pedal assembly into mine. Used the newer version contact switch, spliced in the pink and white wires to my old brake light wires. Set the depth on the new switch, and walahhh....brake lights :)

Jeff

I thought about doing this but my donor vehicle is a manual shift. Its too dang cold to scour the yards to find a 96 auto pedal assembly right now. I think I can make this work if I just take my time and find the issue.
 
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