Disc brake conversion tech/help

[97kurt]

Well I have had some on going issues with the factory drum brakes on my 97 4runner. Basically a tab that holds the lower part of the shoe in place some how bent which freezes the wheel in place.

I've hammered the tab back to being straight again and all is good for a few weeks then the problem comes back. Since I hate drums with a passion I am doing rear disc brake conversion.

So after doing some research I have found that the 4runner/fj40/fj60 can all be converted with a set of GM calipers and some adapter brackets. So today I ordered a set of brackets from sky-manufacturing and a set of modified rotors to fit my axle flange. I should have them by mid next week.


So now I have to figure out the fun stuff...

1) Do I replace my master cylinder with an 80 series all disc brake one
2) Will I need an adjustable prop valve
3) How will I convert the toyota 10mm lines to fit the GM caliper
4) Will my ABS system freak out

Anyways, from what I read the answers to #1 and #2 will both be Yes and maybe. Hopefully I can get some insight on these.

The answer to #3 started off as being a little complex in buying misc lines and adapters until I found this gem on another board.

Nissan brake line (napa 38149), toyota 10mmx1 on one end and GM 7/16 banjo on the other. Nappa part numbers listed on the pic. About $13 each for the lines and $3 each for the bolts (napa 82700), and $? for the washers.

Hopefully someone else on this board with some brake experience can fill in some of the blanks for me.

 

[locrwln1]

Wish I could add something to it, other than wow. That is quite the project. I know that with the 1st gens, it is common to replace the master cylinder with one from a FZJ80. I had a M/C and calipers for my 88 runner for the future rear disc brakes. I sold the truck before doing it though, and the M/C went with it.

Not to question your idea, but can/have you tried new parts in the rear brakes?

Where are the ABS sensors on the rear brakes? The 80's teeth are on the rear hub and the sensor mounts through the backing plate. I think that would be a determining factor on whether your ABS works post surgery or not.

Good luck.

Jack

 

[97kurt]

Wish I could add something to it, other than wow. That is quite the project. I know that with the 1st gens, it is common to replace the master cylinder with one from a FZJ80. I had a M/C and calipers for my 88 runner for the future rear disc brakes. I sold the truck before doing it though, and the M/C went with it.

Not to question your idea, but can/have you tried new parts in the rear brakes?

Where are the ABS sensors on the rear brakes? The 80's teeth are on the rear hub and the sensor mounts through the backing plate. I think that would be a determining factor on whether your ABS works post surgery or not.

Good luck.

Jack

Just my luck, you got rid of the MC. Its ok, I had a co-worker recently toss a 80 series master that probably could of been re-built


ABS sensor on my truck is on the axle tube and the ABS ring is behind the wheel bearing.

As for the current drums, the hardware and shoes are just shy of a year old and my neighbor is actually ASCE certified in brakes. He and I have torn apart and fixed the bad drum about 3 times now.

 

[rusty_tlc]

Lots of cool stuff on the SKY manufacturing web site

So reading their site it sounds like the whole conversion cost less than $300 in parts. Does that sound right?

 

[97kurt]

Yeah their site covers the basics, but they assume you are doing this on an older pickup with out ABS. Only reason why this is even possible is because the flange pattern on my axle is the same the earlier trucks.

I think I have everything I need ordered and I will have to get an adapter made by a brake shop for the prop valve. But from what I see I will be fine with my current master cylinder.