Best Master/Booster for Disc Brake mod?

[srgould41]

I have read lots of articles on 4 wheel disc brake mods, plus the tech section. It seems that when doing 4 wheel disk brake mods there is no consensus on the best master/booster to use.

I have a '71 40 and am building up axles from a '76 to go in. So I have front discs now and plan to mod it with slotted rotors from a V6 along with the calipers (I think that was the preferred mod). I have brackets for the rear using Monte Carlo calipers. I am also putting in a Chevy 305. I will be using 36" or 37" tires.

So I need to use a brake master that will handle the increased fluid requirements, has the correct residual valves, etc. but which one?

What master/booster (from what model/year vehicle) would be the best fit and easiest to add? I have decent fab skills and tools, so cut/grind/weld is no problem to make it all fit.

What do you all think?

Steve

 

[rockcod]

This is my set-up a booster from a 72 FJ40 and M/C from a 90's Toyota Celica Supra and a firewall spacer from JT off-road. Works great for over a year now.

 

[dgangle]

...It seems that when doing 4 wheel disk brake mods there is no consensus on the best master/booster to use....

That is because there is no single BEST way, but MULTIPLE ways of skinning this cat. Or maybe everyone thinks their way is the best. Basd upon personal experience, my advice to you is to use a double diaphram booster and a 1" bore MC from a Toyota or Lexus vehicle with 4WDB. I found this combo from a 92-94 80-series.

There are a multitude of donors that will bolt right up with the required adapter for your firewall (minitruck, 4Runner, 60-series, 80-series, Celica, Supra,......) and many more that can be made to fit with minor to major fab.

Like asking 10 people what is the 'best' food, you will not get a single, definitive answer to your question, at least not here anyway.

 

[pappy]

I run the master cylinder from a FZJ80 on a booster from a FJ62, attached to a spacer from Mark's Off-road. The booster size could be a clearance problem for you. Run a booster that fits.

 

[srgould41]

I agree with you, there is no single best way. My question, and I didn't state it well, is what works well with least amount of modification. So your answer "92-94 80-series" is the kind of answer I was looking for. Yes I can fab up mounts and such, but would rather not .

Thanks for the replies guys. The more replies of what works and fits and what years and vehicles they came off of will help me and will help others down the road (search ).

That is because there is no single BEST way, but MULTIPLE ways of skinning this cat. Or maybe everyone thinks their way is the best. Basd upon personal experience, my advice to you is to use a double diaphram booster and a 1" bore MC from a Toyota or Lexus vehicle with 4WDB. I found this combo from a 92-94 80-series.

There are a multitude of donors that will bolt right up with the required adapter for your firewall (minitruck, 4Runner, 60-series, 80-series, Celica, Supra,......) and many more that can be made to fit with minor to major fab.

Like asking 10 people what is the 'best' food, you will not get a single, definitive answer to your question, at least not here anyway.

 

[JB740i]

I agree with you, there is no single best way. My question, and I didn't state it well, is what works well with least amount of modification. So your answer "92-94 80-series" is the kind of answer I was looking for. Yes I can fab up mounts and such, but would rather not .

Thanks for the replies guys. The more replies of what works and fits and what years and vehicles they came off of will help me and will help others down the road (search ).

Just to put in my two cents is that the last thing most people want to know is what's the best for the money. So we want the best part for the money that fits with the least work.

I bought a booster off of a '96 Tacoma xtra-cab on ebay for $67. I haven't driven it in the last 8 months or so but I know there is something not quite right with my brakes. Maybe the brakes need bled again.

Maybe a check valve is necessary with this booster?

 

[nicholastheczar]

This is something I'm interested in also. I've got a 1970 40 that I'm putting in a SBC 350 and 700R4 and plan on upgrading the brakes. I'll be keeping an eye on what works well for folks out there.

 

[srgould41]

I am going almost the same route. I am installing a 305 SBC and 700R4... I bought newer axles so the front already has discs, but I am upgrading to better rotors and calipers. The rears I am doing the monte carlo brakes.

Want to keep in touch?

This is something I'm interested in also. I've got a 1970 40 that I'm putting in a SBC 350 and 700R4 and plan on upgrading the brakes. I'll be keeping an eye on what works well for folks out there.

 

[nicholastheczar]

in touch

I am going almost the same route. I am installing a 305 SBC and 700R4... I bought newer axles so the front already has discs, but I am upgrading to better rotors and calipers. The rears I am doing the monte carlo brakes.

Want to keep in touch?

For sure. IM me your email address.

 

[vk7ybi]

I recently installed a dual diaphragm booster from a late model 40 and a 15/16 master. I run 60 calipers and rotors on front and Hilux front calipers and solid rotors on rear. This configuration works well for me.

 

[Poser]

I have a '71 40 and am building up axles from a '76 to go in. So I have front discs now and plan to mod it with slotted rotors from a V6 along with the calipers (I think that was the preferred mod).

You do not want to, and will not be able to use the rotors from V6 mini truck/4Runner on the existing wheel bearing hubs that came with a 1976 Land Cruiser disc brake front axle assembly. 08/75-07/80 used a different wheel bearing hub assembly and rotor assembly. You cannot install 08/80 and later style rotors onto the earlier wheel bearing hub assemblies.


The V6 calipers will bolt onto the knuckle fine, but you will need to trim the backing plate if you are still running them to permit the larger V6 caliper to fit.

 

[srgould41]

Thanks Steve. I guess I didn't read deep enough into the tech article. I should have caught that.

What rotor options are there then? To move away from the solid rotor to a vented one... I bought these axles partly to avoid a big knuckle mod on the front. Even if I leave them alone they will be an improvement over the drums I have now.

Steve

You do not want to, and will not be able to use the rotors from V6 mini truck/4Runner on the existing wheel bearing hubs that came with a 1976 Land Cruiser disc brake front axle assembly. 08/75-07/80 used a different wheel bearing hub assembly and rotor assembly. You cannot install 08/80 and later style rotors onto the earlier wheel bearing hub assemblies.


The V6 calipers will bolt onto the knuckle fine, but you will need to trim the backing plate if you are still running them to permit the larger V6 caliper to fit.

 

[Poser]

Hopefully you have vented rotors on the axle currently. If you have solid rotors then either they are packed full of mud, or, someone has swapped mini truck solid rotors and calipers onto a 40 series axle for you. and if that is the case, who knows what year your front axle really is, or if it ever was a small pattern disc brake front axle to begin with.


Look around locally for the earlier rotors; you should be able to find them. If not, SOR and other places have aftermarket rotors for the 08/75-07/80 disc brake front axles. Those earlier rotors only have six holes in them and are held in place on the back of the wheel-bearing hub by six 10mm bolts. The 08/80 and later style have a total of eight holes in them; six for the wheel studs and two for the 10mm bolts that hold the rotor to the wheel-bearing hub. The nice thing about the earlier style rotor is that you do not have to mess around with removing and installing wheel studs in order to replace a rotor.



If you can, post up a couple pictures of what you have on the front axle for rotors/calipers.

 

[srgould41]

Wonderful

I bought them from a fellow seattlecruiserheads club member who said they came off his '76 that he is rebuilding with 60 series axles (his build thread is on here somewhere). I will need to have a talk with him.

I am in San Jose on business. I'll take some pics this weekend when I get home. I am positive they are solid rotors. Thanks for the info Steve.

Steve

Hopefully you have vented rotors on the axle currently. If you have solid rotors then either they are packed full of mud, or, someone has swapped mini truck solid rotors and calipers onto a 40 series axle for you. and if that is the case, who knows what year your front axle really is, or if it ever was a small pattern disc brake front axle to begin with.


Look around locally for the earlier rotors; you should be able to find them. If not, SOR and other places have aftermarket rotors for the 08/75-07/80 disc brake front axles. Those earlier rotors only have six holes in them and are held in place on the back of the wheel-bearing hub by six 10mm bolts. The 08/80 and later style have a total of eight holes in them; six for the wheel studs and two for the 10mm bolts that hold the rotor to the wheel-bearing hub. The nice thing about the earlier style rotor is that you do not have to mess around with removing and installing wheel studs in order to replace a rotor.



If you can, post up a couple pictures of what you have on the front axle for rotors/calipers.

 

[Poser]

Well....

If they are mini truck wheel bearing hubs/solid rotor affair, you can install the 08/80 and later Land Cruiser vented rotors on them.

So all is not lost.

You just have a mix of components and we should figure out what you have for certain.

 

[dgangle]

Steve's description of the two diffferent spindle/vented rotor styles is the best I have read. However, the information in the last post is contrary to what I have learned firsthand. The vintage of mintruck donor parts will dictate which vented rotor style one requires.

vented rotors for the earlier 8/75-7/80 FJ40 use:
Toyota: #43512-6001
Napa: # 85678
Rockautom.com: Allsafe #9820RGS
use these rotors when donor FDB axle parts are from a & 79-80 4WD minitruck

vented rotors for the later +8/80 FJ40 & all FJ60 use:
Toyota: # 43512-6010
Napa: #85799
Bendix/Wearever: #141510
use these rotors when donor FDB axle parts are from any FJ60 or 81-85 4WD minitruck

 

[srgould41]

For sure. I'd hate to order an overhaul kit only to find out that the bearings don't fit...

Well....

If they are mini truck wheel bearing hubs/solid rotor affair, you can install the 08/80 and later Land Cruiser vented rotors on them.

So all is not lost.

You just have a mix of components and we should figure out what you have for certain.

 

[JB740i]

Learn something new everytime these things get brought up again don't we.

 

[4x4Poet]

Aren't the TrailGear 6-stud knuckles a minitruck design?

If so, which era minitruck does their design follow with regard to spindle and rotor differences?

 

[Boing]

Back to the original question, I have used the formula this site has many times over the math works out for any kind of brake system.

Read it twice then get after it...

Brake Upgrade

I would use a master cylinder that is the correct volume for the front calipers & then use a proportioning valve and residual valve to correct the rear brakes...