Topic: 95.5 Dual Diaphragm Booster

[jfrabat]

OK, guys, I need some of your expertise: does the 95.5 booster use the spacer or not?  It seems I will not have enough space between the master and the airbox if I use the spacer but since I have not measured the rod that connects to the pedal, I was wondering how those of you that have done the conversion have gone about this issue...

[sharpxmen]

OK, guys, I need some of your expertise: does the 95.5 booster use the spacer or not?  It seems I will not have enough space between the master and the airbox if I use the spacer but since I have not measured the rod that connects to the pedal, I was wondering how those of you that have done the conversion have gone about this issue...

i don't think you can use the old style MC with the 95.5 booster (i might be wrong but that's what the guy at the wrecker's told me when i bought mine, could be that he just wanted me to buy the MC as well). the 95.5 MC is shorter so overall will fit. the spacer (i assume you mean the one connecting the booster to the firewall) - you need that, i have not seen an install writeup that doesn't use it, i think you'll have some clearance issues if you try to use one with no spacer (and probably be looking maybe at a different booster rather than shortening the rod) - not sure but i think the clutch MC is in the way and could be other things as well.

[jfrabat]

I think i'll try the stock master with the 95.5 booster and see how that goes (I'll remove the airbox to try it).  If it works, I may relocate the airbox a bit forward, or do something along those lines (there is one bottle attached to the radiator that may get in the way; I think it was the PS, but not sure, which I may have to relocate as well...)

[Jeffy]

I don't remember if all '95.5's had the old master or the new one.  I think it may have been the new one though.  Still you shouldn't have to replace it if you don't want to.  The booster will need the spacer.  This is why you cannot use the TJ booster on a YJ, as the clutch reservoir is right behind it and prevents flush mounting.  Relocating the box forward a bit would probably be the easiest way to do it.  You could then replace the elbow with a longer one.

[jfrabat]

I don't remember if all '95.5's had the old master or the new one.  I think it may have been the new one though.  Still you shouldn't have to replace it if you don't want to.  The booster will need the spacer.  This is why you cannot use the TJ booster on a YJ, as the clutch reservoir is right behind it and prevents flush mounting.  Relocating the box forward a bit would probably be the easiest way to do it.  You could then replace the elbow with a longer one.

I'll try it with the old master first; if it works  (I'll roll the Jeep forward with the engine out and see if I can stop it with the brake; if THAT works, I'll try running the engine and stopping it that way, starting at slow speeds and working my way up), I'll get to work on relocating the airbox forward a bit.  I'll need to replace the hose that goes from the valve cover to the airbox (mine is taped together anyway, so this is not at all bad), and find a way to extend the elbow to the TB (I was thinking along the lines of using a flex tube similar to what the snorkel brings, but I dont rememebr if the TB and airbox have the same outside diameter).  I do hope this fixes all my braking issues...

[Jeffy]

If you're vacuum hose is cracked them it very well may be leaking.  You're still running your airbox so you should still have enough vacuum in the intake so that's probably not an issue.  The booster will work with either MC, that shouldn't really be an issue.

[jfrabat]

If you're vacuum hose is cracked them it very well may be leaking.  You're still running your airbox so you should still have enough vacuum in the intake so that's probably not an issue.  The booster will work with either MC, that shouldn't really be an issue.

It's not the vacuum hose that is cracked; it's the hose that goes from the airbox to the valve couer...

[Jeffy]

It's not the vacuum hose that is cracked; it's the hose that goes from the airbox to the valve couer...

Oh that's the Fresh Air Vent hose. It's black hard plastic.  Mine's cracked on the end that's shoved into the rubber FAV fitting.  That's not crucial really.

[sharpxmen]

I'll try it with the old master first; if it works  (I'll roll the Jeep forward with the engine out and see if I can stop it with the brake; if THAT works, I'll try running the engine and stopping it that way, starting at slow speeds and working my way up), I'll get to work on relocating the airbox forward a bit.  I'll need to replace the hose that goes from the valve cover to the airbox (mine is taped together anyway, so this is not at all bad), and find a way to extend the elbow to the TB (I was thinking along the lines of using a flex tube similar to what the snorkel brings, but I dont rememebr if the TB and airbox have the same outside diameter).  I do hope this fixes all my braking issues...

measure the rod that goes in the master (distance from the mounting surface on the booster to the tip of the rod) - i think that is one of the differences - i can't remember what it was, either too long (your MC won't get more fluid and also possibly locking the brakes)  or too short (you won't get enough braking travel out of the MC).

[jfrabat]

measure the rod that goes in the master (distance from the mounting surface on the booster to the tip of the rod) - i think that is one of the differences - i can't remember what it was, either too long (your MC won't get more fluid and also possibly locking the brakes)  or too short (you won't get enough braking travel out of the MC).

Actually, the current booster, in my opinion, has a rod that is too long for the master (at least it seems that way at first glance).  In any case, I'll test it after Easter, and we'll see.  If it DOES work, I need to decide where to put the power steering bottle will be move to.  I am currently thinking either the fan shroud or making abracket to move it...

[sharpxmen]

Actually, the current booster, in my opinion, has a rod that is too long for the master (at least it seems that way at first glance).  In any case, I'll test it after Easter, and we'll see.  If it DOES work, I need to decide where to put the power steering bottle will be move to.  I am currently thinking either the fan shroud or making abracket to move it...

maybe a piece of angle to move it 90 deg - the fan shroud would work as long as you can find a spot that can be bolted on vertically

[jfrabat]

maybe a piece of angle to move it 90 deg - the fan shroud would work as long as you can find a spot that can be bolted on vertically

There's a good spot right next to where the bottle is right now; what I am not sure is if the ford taurus shroud will be strong enough to hold it in the long term.  I like the angle idea, though; let me measure it up and try that one as well...

[jfrabat]

Well, it seems like the 95.5 booster is actually not compatible with the 94 master, so I purchased a used 95.5 master.  The rod from the booster to the master is not the same length, and it's easier for me to just get the new master than fabricating the rod (which is possible, by the way).

Seems I will need to follow this route:

I swapped in the '95 booster and master.
It actually made a really big difference.
Since it is all stock, it was pretty easy w/out any fabbing.
The only thing I needed was adapters to go from my brake lines to the new master.

My '92 MC has a front fitting that is 5/16, the rear is 1/4 and uses inverted flare fittings.
The '95 uses a M12 on the front, and a M10 on the rear with bubble flare fittings.
So, not only do you have to change the fitting size, you have to change the fitting type.
It would be easiest if a one piece adapter existed, but I can't seem to find one.
SO, on the '95 master, I am using 3 fittings on one and 2 on the other. It works, but is pretty ugly.

Here is a quick'n'dirty install:

This project goes better if you bench bleed the MC before installation.
The booster studs are different on the '95 than on my '92. Make sure you get the correct nuts before starting! Oddly enough, the '92 spacer/booster nuts worked on the '95 booster/MC studs. I only needed new booster/spacer nuts.
Remember to chock your wheels!
Okay, with the adapters, MC, and booster in hand I started the project.
Start inside the cab, looking up at the pedal/pushrod union.
The pedal on my '92 had an odd retaining clip for the push rod.
Pop this loose and wiggle the rod off the pedal.
Unbolt the MC from the booster and gently move it aside without damaging the brake lines.
On my '92, I did not have to unbolt the spacer from inside the cab. I just unbolted the booster from the spacer.
I needed to remove the airbox, and unplug the vacuum line from the booster.
The old booster pulled out pretty easily.
The new '95 booster came with a boot installed on the push rod, so I discarded the old '92 protective cover.
Before sliding the booster flush to the spacer, go into the cab and line up the push rod with the pedal to prevent any binding.
The new booster slid onto the spacer with a little persuading. The studs are larger, but go in without any hassle. I was prepared to drill out the spacer holes, but did not need to.
After checking alignment with the pedal, push the booster the rest of the way in. Go into the cab and slide the push rod onto the pedal, reinstall the retaining clip.
Tighten the nuts on the booster to spacer.
I then installed the adapters on my bench bled '95 MC.
Unbolt the brake lines from the old MC.
Carefully bend the lines over from the passenger side to the new drivers side location for the new MC.
Loosely thread the lines into the adapter on the new MC.
Install a new MC to booster seal. My booster came with a new seal.
Carefully install the new MC onto the booster, taking care that the pushrod slides into the MC.
The studs are a different size than the '92 so install and tighten the new nuts.
You should now be able to do any final tweaking of the brake lines.
Tighten the brake lines and top off the MC with DOT 3 fluid.
Reinstall the vacuum line to the new booster, and the airbox.
Go back into the cab and contort yourself to get a good view of the pedal, pushrod, and sensor switch.
On the '92 pull/push the threaded switch toward the pedal until there is contact with the pedal and switch "button".
My brake lights stayed on after this swap and I needed to adjust the switch.
After testing the brakes at a VERY slow speed and verifying that there were no leaks I took it for a spin.
Everything seems fine.
I am going to let the brakes gravity bleed over night.
If there is any air in the line (squishy pedal) I will bleed them.
I will comment on the effectiveness of this swap after driving it for a few days.

So, there is a breakdown of the install.
I am sorry I didn't have any pics. I had to do this at 10 at night to keep my apartment manager from griping at me.
This little project took me about 45 minutes.
Tools I recommend are a good set of flare wrenches and racheting end wrenches (the space between the booster spacer and firewall pretty tight).

[jfrabat]

So, I installed the new setup, but stll the brakes are crappy...  They are actually worse, in fact.  I have not bled them yet, but I doubt it will fix THAT much the brakes.  also, I think my boosteer spacer is wider than stock, as the brake lights stay on all the time; Im thinking of using a set up like the old system (with threads) to adjust for this.

[FourbangerYJ]

So, I installed the new setup, but stll the brakes are crappy...  They are actually worse, in fact.  I have not bled them yet, but I doubt it will fix THAT much the brakes.  also, I think my boosteer spacer is wider than stock, as the brake lights stay on all the time; Im thinking of using a set up like the old system (with threads) to adjust for this.

Bleed them, then report back. Bleeding should help a bunch.