Complete Brake Overhaul

[jeepcoma]

Brake lines are starting to look scary so the next big project I'm going to tackle is a completely new braking system. I've been doing some searching through the forum but wanted to start a thread to collect my own info and notes and ask questions, maybe it will help others who are doing the same.

 

OK so here's the plan, strip out the existing stuff and start from scratch! My height sensing valve still works but has seen better days, BUT I would like to keep a functioning system for those days that I put the MT springs to work and have a heavy load. I'm thinking the best way is with a remote bias adjuster in the cabin so I can just turn a knob and set it. Has anyone done this or have recommended parts? Not sure of everything I'd need to get, but will probably try to figure this out.

 

While I'm at it and doing all the custom plumbing, I'd like to do the dual diaphragm upgrade. From what I've read, I can just order a new booster and MC for a '99 XJ, and it's a direct swap? Something like this:

 

Any recommendations on brand? When it comes to brakes, I don't want to cheap out, so spending a few extra bucks for a new unit vs pulling something from a junkyard isn't a big deal. $50 for a new MC and $75 for a reman booster seems pretty good.

 

Next up is brake line. I was going to go with stainless but have read a lot about how difficult it is to do properly, problems with work hardening the end if you cut it with a regular pipe cutter, harder to bend and form, harder to flare cleanly. I came across this stuff called Cunifer that's supposed to be very good, easier to work with than stainless but also rust proof. Anyone use it before? I'm also not sure yet how much I need to get, but a kit like thiswith both sizes of line and various fittings seems pretty good. My research has ended here for now though, I need to figure out plumbing and what sizes go where. I think that kit should give me plenty of line to work with and have plenty left over for the next job.

 

 

I also got some new tools to do the job right :banana:

 

 

 

[Comanche County]

The MC should be easy to bolt on and plumb. The booster rod however may not be a bolt in affair. I did this in the DIY section. Lot of ways to skin the MC/Booster cat. IMHO, I don't think you'll need to spend the extra money on special hard lines unless you're doing some heavy duty towing/hauling, which the MJ may not be the best rig to use. You're on track though.

[deziped]

Use a booster out of a 98-99 WJ & it is almost a bolt in. No modification of booster/pedal rod necessary. I just did this on an 89 with a booster out of a 99 XJ and it required cutting and shortening of the booster rod which was a PITA. But I did'nt have to cut or bend the firewall in any way to install it. You will probally need a brake line flaring tool also as your gonna be making your own custom fit brake lines from the MC to the distribution block.

[HOrnbrod]

Are you doing the dual diaphragm brake upgrade to your 91? Then the 95-96 XJ master/booster is easiest the way to go. Pure bolt in mechanically by using the stock 95-96 aluminum spacer plate between the booster and the firewall. The only fab mod necessary is bending new lines from the new 95/96 master to your existing combo using the existing combo valve flare fittings on your new lines. The proportioning valve (load sensing valve) will remain as is.

[87Warrior]

I am posting to more or less subscribe to this thread as this is one part of my build I am not sure of.

 

Can you explain to me what tool #2 is and what it does. I understand the flaring tool and bender pliers.

[Boots]

looks like another type of bender to me.

[jeepcoma]

OK, lots of questions so far on the correct booster/MC to get :hmm: . Consensus seems to be that some are direct fits, some are direct with a spacer, and some require rod and/or firewall modification. Will have to keep digging into this.

 

IMHO, I don't think you'll need to spend the extra money on special hard lines unless you're doing some heavy duty towing/hauling, which the MJ may not be the best rig to use.

 

I'm mainly interested in the rust-resistance. A rusty floor is one thing but a rusty flaking brake line is no fun. I'm also set up with the MT springs to haul a decent amount of weight so I want my lines to be up to the job, and not have to worry about them bursting in a panic stop. If I get long-lasting AND high quality out of it at the same time (for a reasonable price), it's win-win. Beats doing the job again in a few years. I'm just not sure yet what sizes, lengths, and fittings I need yet.

 

You will probally need a brake line flaring tool also as your gonna be making your own custom fit brake lines from the MC to the distribution block.

Are you doing the dual diaphragm brake upgrade to your 91? (trimmed) The proportioning valve (load sensing valve) will remain as is.

 

Got the tools (arrived last night, yippie!), and my goal is to eliminate the existing proportioning valve (see concerns RE: rusty flaky brake lines) and replace it with a manually remote adjust unit. I want to keep the ability to increase the rear bias when hauling a load, but not lock them up when it's unloaded. I think something like this is what I need, as it would replace the existing distribution block and allow me to control bias:

 

Can you explain to me what tool #2 is and what it does. I understand the flaring tool and bender pliers.

 

It's a rolling tube bender, makes nicer bends than the fixed units. A bit more pricey but I should get lots of use out of it (same with the flare tool really). The bending pliers are only "meh" quality. I got them mainly in case I need to tweak something on the truck and can't get to it with the good benders. It does pinch the line and leave a mark (bad if you have coated lines), but handy in a pinch (ha ha) none the less. The pinching might be fixable with some light sanding, build quality isn't that great and you can visually see were it doesn't align the way it should. Good to have on hand for $18 though.

[maddzz1]

I have done the double diaphragm booster on my 89. I used the booster and MC from a 95-96 XJ. The spacer Don was referring to comes with the booster. It is just an aluminum spacer and is behind the white cushion stuff on the booster. The only mod you need to do is grind down the end of the booster rod to flatten one side. If your MJ is a 91-92 you may not need to do this.

 

I also used the newer style brake switch and also switched the brake pedal assembly on mine. Switching the pedal assembly is easy if you have a standard and a pain if you have an auto. Again, need to know if your MJ is a Renix or HO, and if its an HO do they use the newer style brake switch or the older style?

 

If yours is an automatic then the shifter cable probably runs thru a bracket on the brake pedal assembly. That bracket isnt on the newer XJ brake pedal assembly because they are floor shifts. I wanted to swap in the XJ brake pedal so I could use the newer style brake switch so I ended up converting mine from a column shift to a floor shift at the same time. Hope this makes sense.

[deziped]

Pic of 99 XJ booster in my 89 using the 1/4" spacer. Required modifying (shorting) the pedal rod.

[ryno1121]

I just bought the parts to do this. The booster did not come with the spacer so I will have to make one. Is it 1/4" thick? Also, the rod on the booster is already flat on the end. Will this need to be trimmed down?

 

Thanks

Ryan

[deziped]

Yes, the spacers are 1/4" thick

[Jeep Driver]

Well...........I have a 98 sitting here and I took a look at it a couple of days ago and thinking about swapping. The MJ brakes do seem a little dead compared to the 98XJ, I assume this is the reason for the swap?

[Jeep Driver]

Exactly what in entailed in shorting the 'rod' and why?

[jeepcoma]

Parts and tools arrived, yippie!

 

 

As far as hardware, I'm leaning towards the Wilwood combination distribution block/bias adjuster, but I'd like the rears to accept the 1/4 brake line so I can run that to the back and then split into 2x 3/16 to each wheel. I think I'll also plumb the 10lb pressure holder into the rear circuit. The hardest part of the process is figuring out what connectors and sizes everything takes, some descriptions are lacking at best. Frustrating!

 

[jeepcoma]

Are you doing the dual diaphragm brake upgrade to your 91? Then the 95-96 XJ master/booster is easiest the way to go. Pure bolt in mechanically by using the stock 95-96 aluminum spacer plate between the booster and the firewall.

 

Did you buy this new, and the spacer was included? What brand/part number? I might need to check this out at the autoparts store to see in person, shopping online doesn't seem clear whether it's included as part of the booster or not. It sure looks like it's there, but internet pictures from a catalog aren't always 100% reliable... Of course I can always grab one from a junkyard but I like to have everything on hand first. I'm going to have to plan all this work for a nice long weekend and don't want to get half-way through only to get stuck on a missing part (I hate that!)

 

[HOrnbrod]

The booster I used was a 1995 NOS anti lock booster (the anti and non-anti lock boosters are the same) and the spacer plate was included.

[Eagle]

Got the tools (arrived last night, yippie!), and my goal is to eliminate the existing proportioning valve (see concerns RE: rusty flaky brake lines) and replace it with a manually remote adjust unit. I want to keep the ability to increase the rear bias when hauling a load, but not lock them up when it's unloaded. I think something like this is what I need, as it would replace the existing distribution block and allow me to control bias:

Your links don't work for me, but if that's the Wilwood adjustable proportioning valve, it does NOT replace the stock distribution block in the front. The Wilwood is plumbed into the single line from the front block to the rear axle, downstream from the front distribution block.

[jeepcoma]

Thanks Don. I ordered the MC yesterday, I got CARDONE SELECT Part # 133180. It has 12x1.0 and 10x1.0 brake line fittings so unless it comes with hardware, I'll be ordering P/Ns M8-4 and M1-3 from FedHill (or maybe just from auto store, but it's easier to link to them for others to see and I'm happy so far with their product, plus it's right around the corner from me in MA) in order to adapt to the regular 3/16 and 1/4 brake hose. I may also need some other adapters depending on the rest of the components I've got lined up.

 

As far as the booster goes, my local Advance Auto carries the Cardone 54-73152. This I want to get in person to verify the plate is included, and it also happens to work out cheaper than RockAuto! Plus I hate dealing with core charges from e-retailers. Not sure if I can return my '91 booster for the core rebate, but I'll ask.

 

Eagle, the Wilwood part I'm looking at is 260-11179. It's listed as a "Combination Proportioning Valve". The two outputs from the MC go straight into the Front Input and Rear Input lines of the unit. There is one rear output (which also includes the bias adjuster) which I would send to the rear splitter (and include the residual pressure valve 260-1876 in this circuit) on the axle. There are two front outputs, which I would send to each caliper. Am I missing something about needing another block somewhere? :dunno: Keeping in mind that I'm throwing out ALL the stock lines and starting from scratch. :hmm:

[jeepcoma]

As far as the booster goes, my local Advance Auto carries the Cardone 54-73152.

 

This alas did not have the plate on it. The Omix Ada one on RockAuto appears to have the plate, but I'm not sure I trust the photo. Besides it's $275, so that's out of the question.

 

Don, do you happen to know the PN or brand of the unit you got, or maybe where purchased? All the local stores around here seem to carry the same Cardone unit. Maybe teamcherokee would have the spacer for sale?

 

Here's the Omix unit, Part # 1671805

[HOrnbrod]

Don, do you happen to know the PN or brand of the unit you got, or maybe where purchased? All the local stores around here seem to carry the same Cardone unit. Maybe teamcherokee would have the spacer for sale?

 

I got mine on Ebay, p/n 4761788, Booster Package w. ABS, and it was a NOS in-the-box Mopar unit. Came with the spacer. :cheers:

[jeepcoma]

I got mine on Ebay, p/n 4761788, Booster Package w. ABS, and it was a NOS in-the-box Mopar unit. Came with the spacer. :cheers:

 

Thanks for that, it was one of the units I found with a pic of the spacer. I ended up buying the Cardone unit due to price and will work something out. I'll measure first and see what I need to do, and also try and find out if I can order the spacer from some source. More to come!

[jeepcoma]

OK this has been done for a while but I'm finally getting around to pictures and details. First things first, this is a GREAT upgrade over the stock system, which to be honest I felt was adequate for light/medium usage with a functioning rear proporting valve and otherwise decent braking components.

 

Part Summary:

• 
  [*:1y21odcx]Required Parts for Upgrade:
   
   
  [*:1y21odcx]CARDONE SELECT 133180 Master Cylinder. This was listed for a 95 Cherokee 4.0
  The big difference here is that this uses METRIC line fittings. It takes a 10mm and 12mm double bubble, as opposed to the SAE fittings in the 91 system and all the other components I used. I went to autozone and picked up the lines I needed, since I could not make bubble flares.
  [*:1y21odcx]Cardone 54-73152 Booster. Following hornbrods suggestion it's for a 95. I got this at Advance Autoparts. It did not include a spacer but I improvised.
  [*:1y21odcx]Wilwood 260-11179 Combination Proportioning Valve. This unit replaced the stock height-sensing valve in the rear AND the distribution block under the hood. The two outputs from the MC feed directly into here and then there's a single output to the rear and one output to each front caliper. The rear bias is adjustable.
  [*:1y21odcx]FedHill CNF-3 - 3/16"/4.75mm OD tubing x 25 foot coil + 10 feet misc line. Working from a coil SUCKED. Big time. Unless you have the special tool to straighten out coils, this is an exercise in frustration and wonky brake lines. It was great quality stuff don't get me wrong, but impossible to get nice and straight by hand. I ended up using all 25' for the rear axle all the way up to the new distribution block, plus the front calipers into the hood. I think I wasted only a few inches, so I pretty much used it all up. It did cover all the areas exposed to salt so I was pleased. This bent and flared like butter, very nice to work with besides the coiled aspect. I used autozone line to finish up under the hood.
  [*:1y21odcx]FedHill #2 Nut Packs for 3/16 line. I used up most of these and got some additional union pieces to make it easier to work with.
  [*:1y21odcx]10mm DIN to 3/16 SAE and 12mm DIN to 3/16 SAE. Any 12" section from autozone will do, as long as it has the proper flare and fitting on ONE side. I cut the other side to length and SAE flared it.
   
   
  [*:1y21odcx]Various replacement parts to finish my refresh:
   
   
  [*:1y21odcx]Wilwood 260-3279 Residual Pressure Valve. Holds 10 PSI in the rear drums. Probably unnecessary but I was curious to try it out, since I was going to such lengths anyway. I'm hoping it gives a bit more consistent initial bite out of the rear brakes, which is more useful with a loaded bed.
  [*:1y21odcx]RAYBESTOS FRC10185+FRC10185 Calipers. Cheaper, easier, and faster than rebuilding myself.
  [*:1y21odcx]DORMAN W17507+W17508 Wheel Cylinders. The right side required some slight grinding to fit into the space in the axle.
  [*:1y21odcx]RAYBESTOS 2515R (2515) Drums. I already had the rest of the rear hardware and shoes from previous work.
  [*:1y21odcx]RAYBESTOS 780444PR+780444PL Premium Rotors. Turned out these are drilled and slotted.
  [*:1y21odcx]RAYBESTOS ATD477M Premium Brake Pads
  [*:1y21odcx]RAYBESTOS BH38894+BH38895 Front Hydraulic Hoses. These are for the front calipers. I might replace with stainless, I didn't read the directions about how to straighten the hose properly so it rubs the tire a bit on full lock.
  [*:1y21odcx]RAYBESTOS BH38845 Rear hydraulic hose. Not running a lift so stock was fine with me.

 

The Wilwood flaring tool was AWESOME. Flares took literally seconds. None of them leaked. Really fun to work with. Just keep in mind that you need a good 2" or so of straight line to fit in the flaring block, so you can't make teeny tiny lines. This is important in the master cylinder area where sometimes you want teeny timy lines.

 

The Wilwood roller bender was... a mixed bag. My brain had trouble with the geometry sometimes and I invariably bent in the wrong direction. It was tough to use on the coiled line that I didn't have perfectly straight. It was also really hard to measure or eyeball the correct length and angle to bend it. If you don't have a lot of time and patience, just stick with repairing short sections of line when they look like they need it. Bending the entire brake system sucked. It did work great for tight bends around the master cylinder, but do remember that there's still a pretty large bend radius. However tight you think you can bend it, you can't. It will always take up more room than you thought. I think if you had good straight line and this mounted in a vice, it'd be ideal.

 

The Wilwood "pliers bender" was invaluable. Once I got the lines mostly in the correct place and length with the roller bender, this was great for the final adjustments in tight locations, without having to pull the whole line out. Big downside is that it pinches the line AND leaves a mark on it. For this reason I only used it on the uncoated FedHill "Cunifer" line, since it's not coated and the material itself is rust resistant, rather than the coating.

 

Cleaned and painted. Hmm, still need those bump stops.

 

 

Surface rust on the drums from just one day of sitting. But ,the new block and lines all hooked up. I also took some time to drill and tap the axle vent to accept the combination block hold-down/axle vent fitting from my 91 style axle, which my 88 D44 did not have.

 

I also did a lot of cleaning and rust prep before winter, especially areas that I would not be able to easily get to again later (like behind the gas tank).

 

Here's a comparison of the two boosters. I "fabbed" a spacer plate by using some stainless nuts and a washer. I did nothing to the rod.

 

Here was my first test fit of the MC and distribution block. I really liked the location and access to the adjuster, but it blocked the washer tank and I just couldn't reach the rear line coming up from the trans tunnel.

 

I gave up on that, moved it to the other side, and had a workable solution which let me put the tank back in and not have to add more brake line (I was all out of the good stuff at this point so I really didn't want to have to do that). It's a bit harder to reach the adjusting knob, but oh well. It's not like I need to change it all that often.

 

Passenger front routing. I moved it slightly, in front of the emissions can.

 

Rear lines and tank reinstalled. I ended up cutting the main rear line into two sections. One goes from the flexible hose to a union just forward of the tank, and the other piece runs straight to the proportioning block. It's really hard to work with long line and get the bends all correct, so if you're comfortable with flaring don't be afraid to cut it up into workable pieces.

 

 

A note on the gas tank, I got these ubolts for an XJ but they are too long. I ended up tapping them the entire length and then cut to fit. Worked great, with new tank straps and stainless locking nuts to hold everything up.

 

Well, there you have it. Upgrade complete.

[HOrnbrod]

Excellent writeup! Especially on the Wilwood proportioning valve. I know now what I will do now when my stock load sensing valve gives it up. :cheers:

 

Move to the DIY forum?

[Jeepman]

Cool Tools can you list the brand and part numbers?

[jeepdoggydogB]

Great write-up! And I agree with Don many of us will be looking at your Wilwood solution for proportion valve replacement. I just saw an old proportion valve component not to long ago go for over $100 on ebay. :cheers: