brake redo recommendations needed

[bryancostanich]

Hi all,

I'm going to purchase the disc brake conversion from MAF for my '72 FJ55. however, while i'm at it, i'm thinking about redoing the rest of the brake system. the lines (hard) are pretty gnarly and the master cylinder is also looking pretty hagard.

see below:

I'm looking for some recommendations, i'm not a brake expert by any stretch.

I'd like to replace just about everything while i'm at it.

couple questions:
-> i see that it has an old vacuum booster on it. is that the same as modern power brakes? i was seeing here: Toyota Early FJ40 45 Land Cruiser Brake Booster Adapter - JTOutfitters that they sell an adapter for power brakes, but do i already have them?
-> if i replace the master cylinder, should i use the same one, or is there a better version available?
-> i want to replace most/all of the hard lines, what size should i use? do i need to stick with 10mm?

what would you recommend i put in here in place of all this stuff to go along with my new disc brakes?

 

[bryancostanich]

ok, so the question about 10mm came from reading on here about the 9mm converters, but that's only for pre '70 FJs evidently. so i'm thinking that i'll stay with 10mm everywhere.

also, i looked here: Rear Disk Brakes on FJ40'S and FJ55's , and that guy recommends the master cylinder from a '92 v6 toyota truck. it looks to me however, that it only has one connector on the bottom of it. the one on mine has two.

what are those connectors for? don't the brake lights get their actuation from closer to the pedal, some sort of switch there?

also, can i bend those 10mm lines around a can or something? do i have to spend a bunch of money to buy a bender?

should i go with stainless steel?

 

[FF LC FREAK]

First off, yes, you do have power brakes. The brake booster = power brakes.

Second, you can upgrade your master cylinder if you want to, but if it is still working, I wouldn't mess with it right now. Simply remove the residual valve on your front circuit when you put on the disk brakes. If your brake lines are kinked or messed up, then yes replace them. Stick with 10 mm.

The connector is for your brake warning light. Its a dash light that lights up if you lose your brake fluid.

You can bend your lines around a can, but you can buy a cheap brake line bender at any auto parts store. I would rather go that route. Stainless steel lines will be harder to bend and cost more. In my opinion, not really necessary. Your stock lines have lasted for 30+ years.

Brakes are a pretty important part of your rig, so double check all your work. Make sure you do it right so you don't end up killing yourself or someone else on the road.

Good luck!

 

[fieldsken1]

if you are going to do front brakes go mini truck or something other them mam a fre you wont be able to use longfield axles with them if you choose down the road. you can bend the brake lines any way you want as long as you dont brake them or pinch them. as far as master booster goes i did use the one for gm from man a fre.

 

[jsuthey]

I would look for a 76 or up front axle to swap in there before you spend The $$ bucks on that kit.I have it,but that was almost 9-yrs.ago before I knew about all the good info here on mud.
I bet for the price of that kit,you could get front&rear axles,then you could rebuild them&do the rear disc.Check the FAQ's for the year change from corse to fine,those would be better to rebuild&do discs on.
I think that would be the way to go,but if you are set on the MAF kit,it's pretty straght forward install.They are good parts,just a bit on the spendy $$ side.Very good upgrade from the old frt. drums!Looks great too,but I still have the corse splined axles.
John

 

[PhilC64]

You can do this all yourself if you're so inclined. You'll spend half of the MAF kit by sourcing the parts yourself.

I just did the rear conversion for cheap. conversion brackets with shims from Proffitt's Cruisers for $50 (Downey Off ROad has a pretty similar kit.) The GM Monte Carlo calipers I got for $24 apiece from NAPA. The fronts I pretty much got the front axle from an 84 LC FJ62. You can also get one from a 4Runner or Tacoma. I picked up a brake master cylinder from a 91 4Runner and it fit perfect.

I got all of my info here https://forum.ih8mud.com/40-55-series-tech/13571-disk-brake-conversion-links.html and followed Guppy's write up for the front conversion. Total time was a long weekend.

 

[bryancostanich]

thanks for all the info. i'm reading, reading, and doing some more reading. information overload. the MAF kit appealed to me because it was simple, but it sounds like the right way to do this is to do an axle build up. oy - what i don't want to do is bite into a project that's going to be a huge time sink.

jsuthey, when you're talking about the axels, doing you mean just the axels, and not the rest of the front-end assembly, differential, etc.?

just to be clear, when you guys say "mini truck" you mean the smaller pickups that toyata makes, like the tacoma, etc.? you don't mean the actual mini trucks that they have in japan, right?

 

[fieldsken1]

yes the toy mini truck front knuckles outward everything just swap and they are alot stronger

 

[FF LC FREAK]

When they say mini truck, it means a Toyota 4x4 pre 1985 with the solid front axle. You don't want the IFS stuff. Or use later fj40 axles with disk brakes or fj60 front axle stuff. If you use a later fj40 axle, you can swap in your current 3rd member and swap in the whole rest of the axle and not even have to swap pinion flanges. If you use fj60 or mini truck stuff, just use the knuckle out and birfield. Like others have said, you can do it for less than what the man a fre stuff costs. It really isn't that hard to do and it is a very worthwhile upgrade.

When I did mine, I got a later 40 axle and swapped in from the knuckle out. That way, I could rebuild my axle with new seals and bearings at the same time. It basically took a weekend to do it. Now that I've done it once, I could probably do it in a long day.

Good luck!

 

[bryancostanich]

know of a good place in SoCal to get these parts? SOR? would they have them?

 

[FF LC FREAK]

www.marksoffroad.net

Mark A owns the shop and is a very knowledgeable guy when it comes to Landcruisers. He is also a supporter of this fine website. Call him up and see what he can do for you.

Otherwise, start perusing craigslist and the junkyards in your area.

 

[bryancostanich]

nice. i'm going to give mark a call tomorrow.

thanks all.

 

[bryancostanich]

dropped by mark's offroad today. that was super helpful. that guy is pretty rad.

thanks for the referral.

 

[jsuthey]

I was talking about the whole axle assemblys(housing,3rds,the whole thing) front and rear.Should bolt right up,then you would have updated axles,to put time& $$ into to rebuild, instead of the older style.
Lots of good ideas from other folks as well,good luck with your build up.

 

[bderrly]

Does anyone know if an '85 mini master cylinder will work in my '70 FJ40? I want to upgrade the cylinder/lines to 10mm fittings, but also want to make sure I get parts that will work.

 

[bsmith123]

Brakes 101

Brakes 101

Good thinking to ask what will go along with your disc brakes. Often the brake systems get mix and matched--better to look at it as a system

As far as bending lines I got the tube bender by leaving a deposit at the Auto Parts---100 percent refund when returned, that was Autozone I think

The adapter you linked to is not necessary since you already have power brakes and that is for a manual to power brake conversion

Here is some general info about brakes you might find useful to know

Residual Valves---keep drum brakes pistons from retracting too far and having to pump to get good brakes. Drum residual valves are higher pressure than disc. On discs they keep some pressure on the seals and keep them from leaking. Often said it is only needed for the rear because the head pressure on the lines will do okay for the front. Drums require 6lbs pressure and discs only 2. You can get adjustable aftermarket ones.

Proportional valve---The proportional valve directs more pressure to the front brakes than the back since most of the braking power comes from the front where the weight is--more weight less skidding.

Metering Valves-- Metering valves apply pressure to the back brakes before the front which aids stability--you still get more pressure on the front but it comes in just after the rear brakes

Master Cylinder Rod adjustment---If the master cylinder rod is not right your brakes will drag or even lock up after a couple of applications opening the lines will release the pressure but then it will do it again until corrected

Master Cylinders --- There are MCs designed for drum/drum, drum/disc, and disc/disc systems---pick a m/c from a model that matches the configuration you decide on

Lines Although the lines probably dont make that much of a diff technically there is a difference in press vs flow for discs and drums use the line for the system you are using if you can.When replacing hard and soft lines use DOT approved brake lines. (for instance the stainless braided hose replacements for the rubber hoses should be DOT approved). Lines are never connected straight line end to end and must always have bends and/or "curly Q's" to allow the line to flex under pressure
Use brake line wrenches, if a line is particularly hard to come off clean it well removing all paint, spray with pen oil, and slide a box end wrench on from the other end (if disconnected) to avoid stripping the nut---they are easy to strip!

Booster --The booster has vacuum on both sides until you apply the brakes then ambient pressure is applied on the pedal side of the booster---it is actually atmos pressure vs vacuum that provides the boost. The plastic check valve coming out of the booster preserves the vaccum inside the booster for a couple of applications if your engine quits---after that you have un-boosted braking


Hope that's useful to you, another post you'll need and to make it through