Has anyone retrofitted disc brakes in the rear?

The UPI kit looks really nice & uses off the shelf Sequoia rear disks.

 

I used the SOS performance Stoptech front BBK with 325mm aerorotor and 6 piston caliper! Also used 4runner OEM rear brakes. Install required a LOT of cutting, lots of time, and a few specialty tools. Would be happy to talk you through my process in more detail, or you could check out my build thread or my disc brake upgrade thread. Both kits cost 3500 total in parts and I installed myself with my buddy's help. Here's the results:

 

It never fails...every time one of these threads pops up there is always someone like you pushing drums with zero personal experience between the two in a Tacoma. The hilarious thing is that your wonderful video filmed by Gomer Pyle in his Sunday best silk shirt standing in his hi tech cinder block shelved shop actually leans on the biggest problem with the drums = fade. If you add a 1000 lbs of of after market goodies to your truck drum fade is a constant daily driving problem. If you add weight to rear end IE: high clearance bumper with a full size 35” spare and a couple of loaded jerry cans and a camper shell you are easily 500 lbs over stock...oh wait...throw in the worst kind of weight you can add to anything with wheels = heavier wheels and tires like the 35’s we all love and you are now 700 lbs over the intended daily driving rear axle weight of those stock drums you are such a fan of.

Now, until you have daily driven your Tacoma with 700 extra lbs over the rear axle you don’t have any valuable input to provide on this debate. Let me enlighten you from someone that has experienced this for years...the rear drums are completely insufficient and fade like your Uncle Gomer in his silk shirt after a fifth of Jack at 1am and are simply scary in stop and go traffic. The basic rear disc conversion from SOS which uses Sequoia calipers and master cylinder ( which is all that I will speak to since that is what I personally own ) is a huge upgrade in stopping power for the rear end, period end of story. My truck with it’s extra 1000lbs of shit on it has better braking feel than stock.

Now, if you want to talk about disc brakes being an upgrade for things like racing vs an expo rig you should ask the guys with the fastest truck on this site @Torspd his opinion. I would love to see you show us all the race cars or race trucks with drum brakes...

 

If the truck in question is a '09+ TRD Off Road or Pro, the electric booster is responsible for most of the poor brake feel. Going to rear discs or steel braided lines won't make a difference in feel.

 

Maybe a little overboard on the ad hominem there brother, but I hear you on the disc vs drum scenario when the weight starts to creep up. Discs allow you to manage heat a lot better, and sadly there is jack and shit in regards to more aggressive aftermarket shoe compounds for the drums. If you make any upgrade to the rear axle, it's pretty much de facto gotta be a disc conversion.

The problem, the biggest problem, and why I always post in these threads is because hardly anyone talks about that Master Cylinder, which is incredibly INCREDIBLY unsafe.

IF YOU USE A MASTER CYLINDER DESIGNED TO ACTUATE DRUM BRAKES WITH DISC BRAKES YOU ARE DANGEROUSLY UNDER PRESSURE AND YOUR TRUCK WILL NEVER STOP SHORTER.

 

I approve.

 

If drums weren't inferior then almost every manufacturer would not have switched in the 70's to disc brakes on the front. There is no logical way to make the argument that discs are not better. Now weather or not it's worth it for the rear of the tacoma? But op covered that in his first post saying if cost wasn't an issue.......etc.

 

Although from an engineering point of view will agree with your statement to a degree, have you tested this or experienced this first hand, on the Tacoma? I am curious why you say never.

 

Lol

 

I will admit that I have not done any direct work with the electronic booster in the TRD Offroad trims, so my experience could be off the reservation with that particular brand of space magic.

However, on your standard front/rear biasing master cylinders that use a vacuum booster, I've done plenty of work with them. Pretty much every manufacturer under the sun heavily biases their brakes frontwards, usually with a "knee point" that looks like this:

Not to seem condescending because I'm sure you can interpret a chart like this, but bascially at a certain point the rear pressure drops off sharply in relation to the front pressure. This happens even on cars that have disc brakes all around, because whenever your rears lock before your fronts, it is bad news. OEMs avoid this like the plague so they bias heavily frontwards, even at the expense of ultimate braking performance.

Knowing that, plus knowing that drums take way less pressure to begin with, I can extrapolate that the knee point and relative line pressures in the rear are even lower on the Tacoma.

I don't have specific numbers to throw around for you, but I can tell you pretty surely that a panic stop with improper line pressure (from stock MC and upgraded rear brakes) will be quite... exciting.

 

Relax fool. The average person isn't hauling payloads as heavy you do.

 

No one ever. What a revolutionary idea.

 

On drum braked multi axle heavy transport trucks, multi-speed manual transmissions, exhaust braking and engine compression braking (jake brakes) allow for decent stopping distances with drum brakes.

People seem to miss that point when talking about how great drum brakes are.

And even with those added features to help, large trucks of all kinds heat up, smoke and burn drum brakes on a regular basis, even at moderate speeds on very steep, short downhills.

I know that their drum brakes work just fine most of the time.

Tacomas don’t have exhaust braking, Jake brakes or multi speed (more than 6 manual gears) to assist with the high speed, high load and towing loads that some us drive and utilize our Tacomas for.

And, most large multi axle transport trucks aren’t traveling at 65, 75, 85 mph or more down steep mountain grades and curves while carrying their wife, children and dogs.

If drums brakes are so great, then why isn’t everyone switching their front discs to drums, their rear discs if they have them, to drums, and driving with four wheel drums?

Yes, I’m aware that most of the braking force is performed by the front brakes, whether it’s a car, pickup truck or motorcycle.

I know that the Tacoma stops decently with the brakes that it has.

My last full size truck with 4 wheel discs weighed several hundred pounds more than the Tacoma, and in car magazine tests it stopped several feet shorter than the Tacoma. 119 ft vs 125 ft.

What if the lighter Tacoma had the bigger, better 4 wheels discs of that truck?

If it did, perhaps it would stop 10, 15, 20 feet or more better than it does now.

At higher speeds, it could possibly mean the difference between stopping well and hitting another vehicle and possibly causing a lot of pain, suffering or worse.

Bad accidents happen every day.

Good brakes are good, better brakes are better.

What’s wrong with having the best brakes possible?

 

The glaring point that everyone is missing is that rear brakes only account for maaaaybe 30% of your stopping efficiency. You are better off upgrading your front brakes before messing with the rear.

 

Well said !! Very true .

 

Every application has a "best" setup. Now, with all the stuff you typed above, tell me, if you were in charge of brake design for Toyota, i gave you average uses and specs and price point for a majority of the target customer, you need to design for 17K vehicle sales a month and you had to give them the best value for the money.

What would you change?

Remember, out of those 17K customers a month, 16980 are not going to add any weight at all except home depot plants and a bit of lumber. They are going to drive normal, no track. Their definition of off road is that grass field they parked in at the last concert.

That is why we have drum brakes on the rear. They work and work well for the vast majority.

 

On a heavy DOT g force test/stopping distance, jakes and intarders aren’t used. It’s all drum. Zero problems. Jakes and intarders serve to reduce brake wear as well as fade during heavy load.


I do these tests with DOT weekly.

 

Not saying youre wrong in that the master cylinder is an issue, but it really hasn't worked out the way you are implying it would @Nitori .. Im still planning on upgrading my MC to the one from the sequoia, but my truck definitely, without any doubt stops shorter. I also dont seem to be having any problem with rear line pressure, as I can lock the rears if I push the pedal enough still which would imply there is sufficient line pressure at the moment. Probably wont last near as long to credit what you were saying, but it still works for now.

 

The door is this way <<< https://www.tacomaworld.com/ >>> I trust you can find it, OP @jayrobot doesn't need that kind of negativity in his thread

 

Last thread like this was a straight ..I gotta leave before I get fired up again.