Rear Disc Brake Conversions

[dogfishlake]

There is really no disadvantage to the rear drum brakes, properly maintained, until excessive heat enters the equation (like in a road race car after a few laps). The drum will work great but cannot cool as fast as a disc can. On a Cruiser you will only ever see this on mountain decent situations. When use of gearing is done, your drums should be more than adequate.

There is however, a "margin of error " gain in the discs but the cost is a lot of mods. No wrong answer here. It really comes down to your specific needs and want/desire to do the mods.

 

[OSS]

Just thought I'd throw this link in there...
The 2020 Tacoma (and all previous Tacomas) still use rear drum brakes and Toyota has no plans to change that in the near future.
At about marker 6:15 in the video below, a Toyota engineer explains why

 

[Hamachi]

Just thought I'd throw this link in there...
The 2020 Tacoma (and all previous Tacomas) still use rear drum brakes and Toyota has no plans to change that in the near future.
At about marker 6:15 in the video below, a Toyota engineer explains why

Great video... thanks for the intel.

 

[skhochay]

Happy Monday Guys,

I searched for information on a rear disc brake conversion here, but came up dry. Who has done this conversion and what's the best source for parts?

Thanks!

and why are you converting? my question? you do not have ABS on these trucks and the rear drum is doing very well, if you looking to sup up your brake then I will recommend you to upgrade brake master cylinder from older tundra fits 1:1 and works a lot better that stock

 

[Hamachi]

and why are you converting? my question? you do not have ABS on these trucks and the rear drum is doing very well, if you looking to sup up your brake then I will recommend you to upgrade brake master cylinder from older tundra fits 1:1 and works a lot better that stock

Thanks. What land cruiser do you got?

 

[Hamachi]

My 62 stops fine now. I would disagree with the "known under powered" comment, but would have to agree that, like everyone else, I would love a little more.

I prefer drums in the rear because you get a much better parking brake that way. I don't like automatics (my 62 has an H55) and I use the parking brake all the time.

It seems to me that the best of both worlds is Tundra fronts (requires 16+" wheels) and stock drums in the rear. You get improved braking on the front where most of the work gets done, and you still have a usable e-brake. I'm sure the 80FF would stop a little better while driving, but my 62 already already stops fine, with the Tundra fronts it will stop even better, and at that point, the marginal increase on the road is not worth downgrading to the tiny little parking brake inside the rear rotors on the 80.

What all needs to be replaced if I go with tundra front disc brakes?
rotors, calipers, pads? Does the master cylinder need to be upgraded too?

 

[Godwin]

Brake Upgrade - The Tundra Mod

forum.ih8mud.com

 

[Hamachi]

Brake Upgrade - The Tundra Mod

forum.ih8mud.com

Thank you for this excellent write up!

 

[cruiserpilot]

Question for hot rodder types: since it seems the big issues with rear disc conversion is lack
of emergency brake. Why not incorporate a hydraulic line lock with in the braking system
similar to drag racers or less hot rodder type tow trucks - which I understand use a line lock for
braking their trucks? Anyone have any knowledge on this?
As far as rear disc conversions, the initial request wasn’t to compare, but looking for a source.
Ours is not to question motivations, but aside from functionality if you LUVMUD, I have heard
rear discs certainly are better functioning, clean up better when contaminated.
I’m surprised there isn’t more rear disc kits out there.

 

[Hamachi]

Question for hot rodder types: since it seems the big issues with rear disc conversion is lack
of emergency brake. Why not incorporate a hydraulic line lock with in the braking system
similar to drag racers or less hot rodder type tow trucks - which I understand use a line lock for
braking their trucks? Anyone have any knowledge on this?
As far as rear disc conversions, the initial request wasn’t to compare, but looking for a source.
Ours is not to question motivations, but aside from functionality if you LUVMUD, I have heard
rear discs certainly are better functioning, clean up better when contaminated.
I’m surprised there isn’t more rear disc kits out there.

Although my original question was for general information, it was just a starting point. I have learned a lot from everyone’s feedback. There seems no limits on the possibilities out there... keep the comments and comparisons coming guys!
I’m now planning on the Tundra front conversion and keeping the rear with all new factory parts.

 

[Seth S]

Question for hot rodder types: since it seems the big issues with rear disc conversion is lack
of emergency brake. Why not incorporate a hydraulic line lock with in the braking system
similar to drag racers or less hot rodder type tow trucks - which I understand use a line lock for
braking their trucks? Anyone have any knowledge on this?
As far as rear disc conversions, the initial request wasn’t to compare, but looking for a source.
Ours is not to question motivations, but aside from functionality if you LUVMUD, I have heard
rear discs certainly are better functioning, clean up better when contaminated.
I’m surprised there isn’t more rear disc kits out there.

The original intent for the emergency brake was too slow the vehicle down if there was a brake failure. So if your ebrake is a line lock and you have a fluid failure then you lose the e brake too. Depending on your state and safety inspection requirements you may not be considered legal

 

[Elbert]

the root question about the parking brake is what are the options out there for a mechanical parking brake when/if you have rear disks on a system that did come OEM with rear disks. I lump the term parking brake and emergency brake together....on light trucks/cars. Notice cars have a mechanical brake on the rear axle. I understand what a line-loc is, but I don't think there has ever been a line-loc on an OEM setup as the parking brake or emergency brake, Which I'm fairly sure the reason is ....if lose of hydraulics you also loose the line-loc.

 

[Seth S]

All the mechanical disc parking brakes on the rear axle I have seen are actually drum brakes that use the inside of the rotor hat as a brake drum.

Saab model 99 and 900 from 70’s to early 1987. After that they had a rear brake. used a front parking brake. The cables actuated little arms that rotated a cam which actuated the brake piston and clamped the rotors. The thought was if you really lost your brakes then the front brakes do most the work so you would have a much more effective emergency stop mechanism.

 

[Feistl]

I was just about to say that...

I’ve done rear disk conversions on my 40s, 61 and 80 series using a disk caliper with inbuilt handbrake (actuated by cable). In 4wd on gravel I can lock up all 4 wheels using the handbrake.

As it uses the normal pads it’s 100% self adjusting and requires no maintenance. It also holds much much better than any drum setup I’ve used (and that’s including fully rebuilt handbrake setups using genuine Toyota parts).

I’ll try and post up some pictures of the conversion.

 

[Mace]

If you are referring to the "eldorado" calipers. You would officially be the very first person that I've seen them work for any period of time.

 

[franklin40]

front range off road has some neat brake conversions. Full-Floater Chunks FJ60

they use a rear set of brakes from the fj cruiser. drum park brake but discs for regular braking. i have a set on my diamond axle for my 40. just need to custom make an ebrake cable.

kinda pricey but is a well designed system

 

[Seth S]

Wilwood sells a caliper with a mechanical parking brake to actuate it but I have no experience with how well it works.

 

[Cruiserdrew]

I don't understand the hatred in this thread for the 80 rear axle conversion. For the cost of an 80 rear axle ($300-$500) you get full float, great disc brakes and a functional e-brake. I've done 2 of these conversions on my trucks and its a winner. You need to swap master cylinders and ebrake cables. Easy stuff.

There is no reason at all to do a bastardized Eldorado conversion that will never work right. ANd you're still stuck with a semi-float axle.

 

[Mace]

Only downside to an 80 rear axle is what to do with the front axle.

 

[tmxmotorsports]

Wilwood sells a caliper with a mechanical parking brake to actuate it but I have no experience with how well it works.

I do