Ditching 5th Gen Caliper "Upgrade"

[Berty_K]

Looking to go back to 4th gen calipers.

Been running 5th gen front calipers and OEM rear calipers for 80k. Here are my observations:

• Front pads have 6mm of pad material left
• Have worn through two sets of rear pads
• Longer brake pedal travel, despite multiple brake bleeds and trying the "40 pedal press" black magic

Decided to investigate further and came across this Braking 101 Article, which states If the new calipers have more piston area, pedal travel will be increased to get maximum braking action.

• 5th gen calipers have a 48mm piston
• 4th gen calipers have a 45.5mm piston

That's a 5% increase in piston diameter per caliper piston.

Larger front caliper pistons means more brake fluid needs to be displaced when braking. I believe the problem with running 5th gen front calipers and 4th gen rear calipers is the rears will engage first because the front calipers require more fluid to be displaced.

If you're running 5th gen calipers front and back, both will have the same piston diameter. Perhaps this means front and rears engage at the same time, but its still unclear to me if this will solve the pedal feel because the brake master cylinder is sized for the smaller 4th gen caliper pistons.

Rather than continuing to experiment, I'm planning on going back to the OEM setup.

Trying to decide between 4th gen WH (larger) or WG (smaller) calipers. I believe my SR5 came with the smaller WG calipers. Both calipers have the same piston diameter, so I'm tempted to go with the larger WH calipers.

I know there are some people on here who have had a similar experience (looking at you [MENTION=50507]CookieRoe[/MENTION]). Which 4th gen caliper did ya'll go with?

 

[xtremewlr]

I have close to 34k miles on my 5th gen front calipers & rotors and 4th gen rears. No issues, still on the same pads I installed. Generic ceramic pads front and rear. Yes, there's slightly more pedal travel but braking is still far superior to what I had with 4th gen fronts. Not understanding how you've gone thru so many sets of pads.

14WA calipers are what are used on 2010-2015 5th gen 4Runners and what I am using on my fronts, along with the larger diameter rotors. I believe 4th gen Sport models came with the same diameter front rotors as these but not 100% sure.

 

[CookieRoe]

Yeah, I'm not impressed with the 5th gen brake upgrade, I've said and stay by my statement that it's a crock. Anyway, I'm still "sporting" the 5th gen brake components, since the original ones rusted and seized. Pretty sure my next (year) sets will be replaced with the OEM size and set up (RockAuto is your friend). All I wanted to do was to rid myself of seizing calipers, but that didn't happen after 2 of them (remember one rusted and seized and my current ones are starting to "click"..... indication for me that it's starting to seize). I've reserved to the fact that these brakes are what they are, unless you can upgrade to Lexus GX brakes. I read somewhere that those piston come coated unlike ours........ whatever. Anyway, good luck to all

I know there are some people on here who have had a similar experience (looking at you [MENTION=50507]CookieRoe[/MENTION]). Which 4th gen caliper did ya'll go with?

 

[Inv4drZm]

Could have the stock pistons and or calipers sprayed with cerakote. I about went down this route but haven't had issues with seizing except once. Theoretically it should help with seizing though when I looked into it only dirt bike guys were doing it.

Pretty happy with my stock 4th gen sport sized stoptech replacement rotors and pads, cryo treated and slotted. Those in addition to stainless brake lines give me great braking on 37's, no pulsing since I installed a few years ago.

 

[4RunnerAquasport]

Upgrade seems to help on mine. But, on the first go round with Centric 5th gen calipers, one of the pistons seized in less than 3 years. It was stuck so bad, penetrating oil, heat, and compressed air would not get it to budge. Not impressed with centric.
So this time I have OEM 5th gen calipers. We'll see how they do.
One thought I had if the pressure and fluid increasing with the larger pistons is that significant, then the 15 to 20 year old rubber brake lines are most likely expanding, adding to lack of proper pressure and longer pedal travel.
Upgrading rotors and calipers without also adding stainless brake lines, might not be that much of an upgrade.

 

[LOSTR4]

I went with the larger rotors and swapped on some Power Stop Front S6278 calipers...they have been surprisingly better than I assumed they'd be....Lots of heavy rolling down mountain roads and they definitely have provided me better than OE 4th gen braking...granted, these are meant for the 4th gens...I'm happy and got a good deal on them thru, ahem, Amazon: https://www.amazon.com/gp/product/B079396VZN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I used some DBA rotors and semi-metallic pads and they bite! Might be a nice "in between" setup for your reversal...I'm also on OE 4th gen rears...

 

[bob3dsf]

For those who have had their front caliper seize, what was the condition of the dust boots? I can't see any reason the quad piston design is prone to seizing just based on that. When I had a piston seize on me, all my dust boots were brittle and torn to some degree from the repeated heating and cooling of the brakes. This allowed water, especially winter salt water/brine solution, to work its way into the cylinder bore through capillary action. I'm of the opinion that to truly eliminate seized calipers, a re-boot/ re-build needs to be done at some interval (50k maybe, not really sure). Or, just get reman'd caliper from napa, etc.

I've read various opinions on the value of re-building the calipers. I did it because I wanted to do it. It's not very hard. if you are doing all the other brake service tasks, this isn't much extra. I had 1 piston that was too corroded to reuse, so I bought 1 new one from rock auto (centric brand). Fit perfect, working like OEM. The only thing extra to get, I would say, is a tube of the pink soap base silicone grease. The tiny pack that comes in the reboot kit isn't enough.

FYI: Anyone who decides to re-builds and soaks the calipers in a rust remover... you'll need to paint them. The OEM ones have some kind of coating/bluing to prevent rust. The rust remover took that off.

 

[Berty_K]

Update on this. Went with used OEM 13WH calipers off a GX. Happy to report brake pedal feel is completely back to normal. Been about a year.

 

[Runnin on E]

For those who have had their front caliper seize, what was the condition of the dust boots? I can't see any reason the quad piston design is prone to seizing just based on that. When I had a piston seize on me, all my dust boots were brittle and torn to some degree from the repeated heating and cooling of the brakes. This allowed water, especially winter salt water/brine solution, to work its way into the cylinder bore through capillary action. I'm of the opinion that to truly eliminate seized calipers, a re-boot/ re-build needs to be done at some interval (50k maybe, not really sure). Or, just get reman'd caliper from napa, etc

This right here. Years ago I had a sports car that was notorious for brakes seizing. There was a company created to re-sleeve the calipers with a stainless liner and they also added stainless pistons to complete the kit. This "cured" the seizing problem forever.
If you are fond of the dramatic water crossings (water over your hood) or any other fast water crossings, then you should maintain your brakes on a more frequent schedule. Really that goes for the whole truck when you wheel a lot or choose the "hard line". But this also applies for salty environments or any other driving on non sunny flat paved roads.
Changing to a different caliper might only be that Mfg has a different dust boot set up, as above suggests that is the only way that contaminants get in there. You wouldn't always necessarily have to buy or rebuild your calipers, just get in there and take a look at whether the seals are doing their job.
I understand that not everyone can do this type of maint. I would agree that pulling wheels off in the driveway is not exactly fun (for most) and it is much easier if a lift in involved. Find a good mechanic and plan on taking your T4R in on a more regular basis (or just buy calipers every year or two).

 

[boduke0220]

Are 5th gen brakes the same at GX 460 Brakes?

 

[Berty_K]

Quick update on this thread. WH calipers are still going strong and am glad I went back to the OEM 4th gen setup.

Would still NOT recommend the 5th gen brakes as an upgrade.

Stick to 4th gen parts (WH or WG).