Rear disc brakes

don't forget this for the rear window

 

Appreciate the insight. The DOT4 fluid has made a noticeable difference. So much so I put it in my Subaru. Not being overly aggressive, just don’t think these brakes were made for much more load over stock

 

Not going to argue the benefits of either system. I did the conversion and to me it was somewhat worth it. You're partially correct that the 4Runner parts will work. But you'll need a backing plate. There are two companies that I know of that make/sell a conversion kit. Pedders in one and their kit runs around $1800--which is insanity. I've only ever seen CAD drawings of the kit and never an actual installation. The other vendor is SOS Performance. Their kit is considerably cheaper and can be made cheaper. What I did was buy their backing plate kit and then sourced the remaining components through Rock Auto. I saved a few hundred bucks doing it that way. I also did their master cylinder upgrade the same way. I made some small modifications to the kit, but they weren't necessary. Other than that, they've been on the truck for a year and a half with no issues and multiple off-roading trips. The parking brake works fine. It holds the truck under mild load on the throttle.

 

I think the #vanlife phenomenon is picking up, which mean all those trend following ex 2fast2furious bros will (god willing) become ex Tacoma/overland lemmings

 

I’m happy with the drums on my Taco. I have pulled plenty of extra weight and never had any issues. I also understand that, much like motorcycles, rear brakes only do 10-15% of the work so what they are don’t really matter too much. Drums have much more surface area in contact under braking, and being in the rear, they are less likely to fade from heat since the front disks are doing the majority of the work.

Here is some more info from Wikipedia, which further explains it. For Toyota, I think the rear drums are most likely due to lower weight and brake drag, thus giving every Taco 0.00001% better mpg. It all adds up when you are dealing with cafe requirements.

https://en.m.wikipedia.org/wiki/Drum_brake


Drum brakes are used in most heavy duty trucks, some medium and light duty trucks, and few cars, dirt bikes, and ATVs. Drum brakes are often applied to the rear wheels since most of the stopping force is generated by the front brakes of the vehicle and therefore the heat generated in the rear is significantly less. Drum brakes allow simple incorporation of a parking brake.

Drum brakes are also occasionally fitted as the parking (and emergency) brake even when the rear wheels use disc brakes as the main brakes. Many rear disc braking systems use a parking brake in which the piston in the caliper is actuated by a cam or screw. This compresses the pads against the rotor. However, this type of system becomes much more complicated when the rear disc brakes use fixed, multi-piston calipers. In this situation, a small drum is usually fitted within or as part of the brake disc. This type of brake is also known as a banksia brake.

In hybrid vehicle applications, wear on braking systems is greatly reduced by energy recovering motor-generators (see regenerative braking), so some hybrid vehicles such as the GMC Yukon Hybrid and Toyota Prius (except the third generation) use drum brakes at the rear wheels.

Disc brakes rely on pliability of caliper seals and slight runout to release pads, leading to drag, fuel mileage loss, and disc scoring. Drum brake return springs give more positive action and, adjusted correctly, often have less drag when released. It is however possible to design special seals that retract the piston on a disc brake.

Drum brakes emit less particulate matter (PM) than disc brakes, as the wear-particles are mostly sealed in. They are not better in this regard than frictionless brakes though.[5][6]

Certain heavier duty drum brake systems compensate for load when determining wheel cylinder pressure; a feature rare when discs are employed (Hydropneumatic suspension systems as employed on Citroën vehicles adjust brake pressure depending on load regardless of if drum or discs are used). One such vehicle is the Jeep Comanche. The Comanche can automatically send more pressure to the rear drums depending on the size of the load. Most other brands have used load sensing valves in the hydraulics to the rear axle for decades.

Due to the fact that a drum brake's friction contact area is at the circumference of the brake, a drum brake can provide more braking force than an equal diameter disc brake. The increased friction contact area of drum brake shoes on the drum allows drum brake shoes to last longer than disc brake pads used in a brake system of similar dimensions and braking force. Drum brakes retain heat and are more complex than disc brakes but are often the more economical and powerful brake type to use in rear brake applications due to the low heat generation of rear brakes, a drum brake's self-applying nature, larger friction surface contact area, and long life wear characteristics (%life used/kW of braking power).

To list advantages of drum brakes:

• less expensive to produce
• slightly lower frequency of maintenance due to better corrosion resistance compared to disks.
• built-in self energizing effect requires less input force (such as hydraulic pressure).
• wheel cylinders are somewhat simpler to recondition compared to calipers.
• minor weight savings, primarily from much smaller and lighter hydraulic cylinders vs. calipers.

 

Cheaper so Toyota makes more money

 

8 whole years of being a service tech, huh? Dayum. You may as well be an engineer.

Wait, nvm. I know a garage full of service techs that have been working on our fleet for a lot longer than 8 years, and they STILL cant seem to keep our cars on the street for shit. It seems like I can diagnose our problems better than they can at least half the time.

Time served =/= aptitude. It certainly doesn't equate to a knowledge of the functional benefits of one system over another except for, in this case, ease of maintenance or repair.

 

Engineer here... you called?

 

Physics 101 doesn’t require an engineering degree... brakes aren’t that complicated. A diagnostics prodigy like yourself should know that.

Also, nobody said service tech but I’m guessing that doesn’t mean shit to you.

 

Those are your labels not mine. Toyota was frank about drum brakes being cheaper when the 2nd gen first appeared in Sept 2004: https://www.motortrend.com/cars/toyota/tacoma/2005/2005-toyota-tacoma/ This was before Seatbelt Buckle Mike came up with all the wonky explanations to dance around the issue.

 

It's like clockwork, every few months a noob comes along and starts this disk vs drum shit-show.

 

I don’t recall him mentioning 5 bucks.

 

Like I said. Love this shit.

 

TW needs more fun ways of expressing emotion, so I'm dropping these off here:

 

No. 5 bucks may have been an exaggeration. 5 bucks in the cut-throat automotive environment would be a lifetime achievement award worthy of cover page articles in SAE Automotive Engineering magazine. Actual saving with drum brakes was probably closer to $3