Rear Disc Conversion Information

Yeah, I don't know if all the guys who do these conversions simply because "they don't like drums" understand the complexity of bias, especially on trucks.

 

I very much realize there is a difference. As I said, I plan on doing the master cylinder, but making claims before even looking at the kit is a little jumping the gun; wouldn't you say?

I did some more searching and most concerns in a disc conversion is the valve that may or may not be present in a drum brake line and the possibility of lower pressure. The articles agreed that most manufacturers have moved away from the valve and changed wheel cylinder design. The lower pressures were only a concern in the old two pot style master cylinder because of fluid capacity.

I have no plans for stoptech brake upgrades. I'm not a fan of their products for starters and it adds complexity to something I'm trying to keep as simple as possible. Once I get this done my only brake upgrades will be pads.

I appreciate your input.

 

I figured there was a reason why a simple solution like this wasnt implemented. Probably the closest donor for the tacoma would be either 4runner or FJ as a starting platform-- but I dunno if they have the same ABS/VSC/etc profiles for the truck as you mentioned later needing multi-loading conditions.

 

Any Four wheel disc brake conversion is all about the master cylinder and proportioning valve set up. Physically putting the disc brakes on the axle is very easy but making them work properly that’s a whole different thing. The best way to do this conversion will be when Toyota ads factory rear disc brakes in 2020 you’ll be able use that master cylinder set up which should be pretty straightforward.

 

Did you ever do your master cylinder? I looked at the schematics I do not know if you guys have the electronic brake booster or crawl control the master cyclinder does not look like anything I have ever seen. It has a selonoid on it and looks like a bitch to mess with. Did you guys have electronic brake booster from Crawl control when you changed out your master cyclinders?

 

I did do my master cylinder, I have a TRD sport so it has a traditional hydraulic MC and I drive a manual so no crawl control. The master cylinder went together just as you’d expect, just pulled out the old, installed the adapter, and plugged in the new

 

I did a drum/disk swap in my 2000 Celica GT from a GTS and it was easy peesy. Backing plates and calipers. Tacos?, I don't think so.
I just hate changing drum brakes! Discs are SO easy!

 

Yeah it took a little while but overall was a straightforward install! Totally worth it for the result, can easily tow more weight without worrying about it and stop on a dime when not towing but it definitely was pricey. And keeping around some extra stoptech aerorotors was nothing to sneeze at either, those shits are like 400+ each for the big ass taco rotors

 

This sounds like a lot of time, effort, frustration, & money spent to fuck up a perfectly adequate factory system to achieve, at best, mediocre results & potentially, major headaches from compatibility issues from other factory systems. Good luck!

 

And just think of the fun a lawyer could have with this if there was an accident down the line; even if not your fault.

 

You guys are a trip. There’s nothing any lawyer could do about it, the brakes demonstrably work much better than what was there. I’ve done testing on my own truck, I know that it has the ability to stop much quicker. The only situation where those brakes would cause an accident is if someone is tailgating and didn’t have time to react, and then there’s nothing any lawyer could argue to get that person out of being at fault.

 

I believe that the only downside to this (once proper balance is achieved) is adding more rotational mass to the rear vs drums? I wonder what the weight difference is.

 

Here's 30 pages of brake goodness, from 2016 until today. https://www.tacomaworld.com/threads...group-buy-2005-2017-tacoma-and-others.456164/

 

The only real test you can really do is brake distance test from 60mph, you'd have to do it like 5 times before and after to get any tangible data. I find it hard to believe you did a 60-0 brake test to compare

Even then when you look at Chevrolet Colorado, Ford Ranger and Toyota Tacoma, despite the Tacoma having smaller brakes (12.2 vs 10.8) and rear drums (Ford and Chevy use disc), the Tacoma braking distance is comparable. The other trucks just get about 500 more lbs of towing capacity...

 

Yes, the majority of braking stress(heat) is in the front of most any vehicle, so it would make some sense to maximize the front heat sinking ability before modifying and perfecting the bias in the back, but every little bit helps in applications where you will generate more heat.

 

Now Stephen, you know better than that. If any accident ever happened, you now assume the liability of your modded brake system instead of Toyota. Chances of happening? Not much. But if it ever did happen, you would have to be liable and that goes for any mod.

Generally speaking, I never did worry about myself or other drivers getting hurt by my mods. But when I became a Dad, I started worrying one of my mods could hurt one of them. So, I gave up most heavy modding.

 

Respectfully, that’s not quite 100%. In order for liability to shift to me, the insurance company covering the other party would have to prove that my modifications were incorrectly or inadequately installed in such a way that my work was what caused it to fail. In all other cases, the liability would fall on Stoptech as the company who made the parts. The master cylinder is a genuine Toyota part so that doesn’t complicate the liability question in and of itself. Either way, those brakes have been on the truck for 2 years and still work great, have a firmer pedal than most new cars and stop the thing on a dime. I get where you’re coming from but I don’t agree 100%.

 

By dime, do you mean 130 feet from 60-0?

 

Lol I didn't say it would or would not be your fault. Just by modding the liability shifts is all.

 

For what it's worth, in general, Toyota generally sizes their drum brakes and disc brakes relatively equally. When converting to rear disc brakes it is rarely required to change hydraulics or bias.

Also for what it's worth, the brake proportioning on the Tacoma is done via the EBD system and as such, there is no biasing done at the master cylinder. Short of running a master with two diameters or some other wacky setup, you're not going to change the bias at all by changing the master cylinder.

I haven't run any brake bias numbers between the drums and discs, but I would be extremely surprised to find there is any significant change in brake bias when swapping out the drums for discs on a Tacoma.

Jeff