Brake Question for 1ton cruisers

[mookie]

those of you who have put 1tons under your cruiser what are you doing for a master cylinder and how do you like it, how well does it stop your rig? i'm putting in a Ford D60 and it has these huge dual piston calipers, on the rear i'm running 3/4 gm disk brakes on my 14B, currently my FJ40 has a FJ80 master cylinder and factory booster. does anyone know of a hydroboost or 1 ton master cylinder out of something that will bolt up with relative ease and minimal modification?

thanks!

 

[bustanutley]

Its common that people swap the massive 1 ton brake hardware to 3/4 ton stuff which brings the hydraulic ratios down a more normal range and also drops a ton of weight. Azcrawler did a nice right up about the swap and had a 3/4 ton front and rear combo working fine with a 1" master (same as fj80).

http://www.azrockcrawler.com/_images/tech/2005/10-14-0534tonbrakes/34tonbrakeconv.html

 

[KurtFj40]

I run a 80 booster with a homemade adapter plate to a 1/2 ton chevy master cyl. It works great. That is with stock disks on the 60 and 3/4 ton disk brakes on the 14b

 

[mookie]

I run a 80 booster with a homemade adapter plate to a 1/2 ton chevy master cyl. It works great. That is with stock disks on the 60 and 3/4 ton disk brakes on the 14b

Whats the diameter of that master cylinder?

 

[Boing]

Here are some numbers I ran from one of my brain dumps...

Dont know what the size of the Ford calipers are, if I get them I can add them to the graph...

Toyota single diaphragm booster (First gen mini) is 7:1
Toyota late style (3rd gen) dual diaphragm booster is 5.7:1

I dont have it on this pic but there is also a larger 3/4 Ton Dana 44 caliper, the one listed is the Dana 44 1/2 ton...

Only other thing to keep in mind is pedal ratio, that being said if your using factory cruiser pedals you should have options as those pedals are long and can be modified easily...

For reference I am going to use the vacuum operated 02 escalade master cylinder with GM Dana 60 front calipers and half ton calipers rear. With a Toyota dual diaphragm its 6.3:1, so it wont be cushy soft like a normal dual diaphragm...



After all this, the war pig just uses an FJ-80 master and it seems to stop ok without to much pedal effort. I think there is more braking power available with a larger master, and increased pedal effort...

 

[mookie]

Some good info here

http://www.pirate4x4.com/forum/general-4x4-discussion/1078832-brakes-suck-need-better.html

 

[shaka 55]

http://www.sky-manufacturing.com/new/detaproduct.php?id=216;)

One ton master cylinder adaptor. Note: use an 80 or taco booster

 

[mookie]

^^^pretty sweet!

 

[Mace]

I'm running the Montecarlo calipers (rear) and stock D60 front calipers with a 80 series master on my 40. I can still lock them up just fine. Seems to work just fine for my application.

 

[mookie]

update on this.....i finally got my axle swap done and i have mushy brakes, it will lock up all four wheels on asphault but it happens close to the end of the pedal stroke (pedal near the floor), there's a definite "oh sh!t" feeling when i first hit the brakes. i'm wondering if i need to add some residual valves? Supposedly the 80 series master cylinder may have them built in? but i haven't been able to get a definite answer on that, and mine came from jt outfitters and may be a abs unit? and yes i have bled them several times both ways- pushing fluid from the cylinder end and pulling it from the bleeder valves.

 

[TCinVA]

I run the 3/4 ton brake kit front and rear on mine. I bought them from "Gubni" on pirate. With the V6 mini truck booster and master cylinder I already had in my 40, they work perfectly, good pedal and great stopping power. I was able to use 15" wheels with just a little grinding.

 

[GLTHFJ60]

update on this.....i finally got my axle swap done and i have mushy brakes, it will lock up all four wheels on asphault but it happens close to the end of the pedal stroke (pedal near the floor), there's a definite "oh sh!t" feeling when i first hit the brakes. i'm wondering if i need to add some residual valves? Supposedly the 80 series master cylinder may have them built in? but i haven't been able to get a definite answer on that, and mine came from jt outfitters and may be a abs unit? and yes i have bled them several times both ways- pushing fluid from the cylinder end and pulling it from the bleeder valves.

Sounds to me like you're not moving enough brake fluid with your pedal stroke. What size MC did you end up with?

I'd step up the bore by 1/16" and see if you like it.

 

[mookie]

still got the jt outfitters fzj80 master cylinder

 

[Mace]

I have 2 lb residual valves on my rig.

 

[BionicCruiser]

IIRC, my MC is a chevy 1 ton truck adapted to my FJ40 booster. I went to that for the bigger diameter. it works great with no residual valves.

 

[zebrabeefj40]

Check out post 2 here:

https://forum.ih8mud.com/40-55-series-tech/305215-chevy-booster-master-cylinder-fj40.html

I had the same combo as you: Ford dual piston calipers on the front and 3/4 discs on the rear 14B. With the stock MC had the same issue as you: crappy brakes. I made an adapter like the Rockstomper piece in the link to a '74 Chevy K30 MC. Bolted that to the stock booster, reflared the proper sized nuts to the Cruiser lines and after that had great brakes for cheap. No need to swap to 3/4 ton stuff IMHO.

Nick

 

[mookie]

wow, some great info in that post