I was just thinking. With all the issues we are having with the 4th and 5th gen calipers, has anyone tried a used set of say Brembos off a Caddy CTSV, Camaro, BMW, Subaru WRX etc. They look pretty similar in mounting but the possible issue would be the curve around the rotor. There has got to be something out there that will work besides expensive big brake kits.

I'm sick of changing calipers. My current '06, on 3 front set(one 5th gen), second set on rear, my first '08 2 on front (one 5th gen) 2 on rear,(one 5th gen), my current '08 2nd set on front( one 5th gen), my rear left just failed so it will be the second set( just ordered 5th gen)

You might, but it's probably not worth it.

Offhand, you need to find a caliper where all of these things are just right:

* Mounting bracket hole size and spacing match the 4R's knuckle

* Height of the caliper/pad needs to fit the rotor but not overhang at all.

* Caliper offset from the bolt holes to the centerline of the rotor needs to be just right

* Piston capacity/fluid capacity of the calipers need to be close enough for the master cylinder to push enough fluid or you'll end up with little to no brake feel and maybe crappy performance too.

* Caliper internal width needs to accommodate the exact right size of rotor and pad.

* Available pads rated for the higher weight and abuse of the 4R vs a sports car, especially if you're towing

* External dimensions of the calipers may not fit your current wheels


Some of that list can be solved by also replacing rotors, wheels, and using custom adapters or mounting brackets to make things work. It's just a lot more involved than most people realize, and a giant pain in the ass to do safely.

Ok new here, so firstly I have to say I am shocked to hear about the caliper issues. (I just bought my first T4R, a 2008 Sr5, and sure enough the guy selling it to me had to replace a caliper!)

As for your question/suggestion of using larger performance calipers off another rig.

It is doable, coming from my background of Jeeps/Chevys/Other modded and tinkered with rigs BUT it comes with some caveats.

Namely, most of them were mentioned above by the other member, where you're dealing with spacing, alignment, etc.

However, if you're a handy machinist or have access to a friend with a CNC plasma cutter/waterjet, having custom adapters machined or cut out would be doable (albeit pricey).

The bigger issue may be the proportioning valve issue. I had a friend once mount Porsche Brembo calipers on his old G-body project (I think a cutlass?). It was going to be an Auto-X car. In the end, he ended up using single piston GMC Truck calipers. Why? The Brembos weren't really set up for his braking system.

Now, maybe if he had installed the Porsche Pedal, Master, Lines, Calipers, Rotors, etc.... then probably?

But once you begin frankensteining systems that were never designed to work in unison, you get into weird issues of pressures and flow of fluid, proportioning etc.

Heck, even when you do a Drum --> Disc conversion on a 90s Jeep Cherokee, by using the rear brakes off a Grand or Liberty, you HAVE to get the Proportioning valve off a ZJ Grand. And that's just going from drum to disc within the same manufacturer AND Generation!

So it can get tricky!

THAT ALL SAID.... I love a good frankenstein project, so keep us posted

These are the only big brake kits besides Brembo that I know of:

CEIKA Custom Big Brake Kit for Lexus GX470 (UZJ120) (02~09) - Ceika Performance

RR Racing Front Big Brake Kit for Lexus GX460 GX470 & Toyota 4Runner

There's a couple more:
FJ CRUISER 4Runner GX470 | SOS Performance, Tundra Tacoma, Stoptech Big Brake Kit Rear Disc

and

Shop | Apex Overland | Off-Road Part Accessories

In my opinion, Ceika is likely the best option. You're not likely to receive a drawing or spec list with an engineer's seal saying these parts are totally fine to use with your truck/application, etc. So, the next best thing is to get them made for your truck by a company that makes brakes.

The all-weather dust boots are a big thing for anyone living where rust happens. I've been told it's common for OEM "BBK" setups for STi's, etc, to not have these extreme weather dust boots (as they're brake systems intended for track use), and as a result, those calipers have ongoing issues with pistons getting seized in place due to rust/dirt/debris/environmental issues... as they were never meant to go down dirty highways for a hundred thousand miles.

in any case, the design issues of adapting other calipers are the most obvious barriers, of course. But, I believe it would make the most sense to pay good money for good parts here, for the braking system. Pads are pads, rotors are rotors, kinda. But the calipers and the hydraulics, if they have problems, that's gonna be a real problem for everyone around, real quick.

Issues with 4th and 5th gen calipers are mainly isolated to states where salt is used on the roads during the winter. In states that don't use salt, the issues aren't nearly as common.

I've done the 2010-15 4runner calipers and rotors upgrade on the front on my 2003 and retained the stock rear calipers. I've had zero issues in over 40k miles since I installed them. I also live in southern Arizona, where there is no salting of roads in winter, even when it snows. And it does snow here. This change to the front calipers also does not require a proportioning valve. It's a direct bolt on, plug and play swap, other than maybe having to trim the front backing plates which is dependent on if your 4th gen 4Runner was a Sport model that already had the larger rotors or not.