Should I upgrade my brakes? 319mm to 338mm?

[Bumbo]

I have a 2004 SR5 V6 4x4
OEM Rim was a 16"

The front passenger caliper is seized and I was going replace it but I noticed this generation came with two different size brake systems in the front.

I THINK I have the smaller 319mm rotors... can anyone confirm.

Questions:

Can I do it without changing anything else in the system?
Is it worth it?
Anyone notice a difference?

I presume the only disadvantage is I cant use a 16" rim anymore?

 

[Morphyne]

Well, bigger is always better. However, you will have to either cut, bend or replace your dust shield in order to make this happen. so to do it right means taking the hub assesmbly off, which isn't terribly hard, but if you have not done your front wheel bearings yet, this is a perfect time to do them.

As you has already noticed, I am unsure about the 16 inch wheel.

Depending on you cash situation, this would be a big job as to do it right would mean:
17" rims - https://www.amazon.com/Toyota-4-Run...qid=1472818657&sr=8-1&keywords=4runner+wheels
new hubs - couple of online guys here so $350 for the pair.
new dust shields from a sport model or a gx470 - junk yard (backing plates are expensive - http://www.partznet.com/toyota/4run...-scat/?part_name=backing-plate&position=right )
and then of course the calipers, rotors, and pads. - i like autozone duralast as they warranty their parts and all I have to do when my calipers re-seize after a year (they did and will again) its a free swap.
And since you are changing the wheels, might as well get bigger tires because now you have better stopping power, which of course will require new shocks and springs....

So you can see how this goes down the rabbit hole quickly.

So with all that being said, to do this right would be a monster job but when you are done you would have a significantly upgraded ride.

What would I do? Well, I would just go down to autozone and buy the best rotors pads, and calipers they sell and drive it and be happy. and that's what I did. I drive like an ******* and these brakes perform wonderfully on 265/70/17s

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[Bumbo]

Sir, I am already down that rabbit hole, lost, and cant find my way out of it... Plus I got a bunch of that check list done already...

Lifted on 2.5" coilovers...
Just bought (5) 17" FJ Rims
Just got (7) 255/75-17 BGF M/Ts

Already planning on buying quality pads and rotors... I was about to pull the trigger on the Centric Premium rotors, calipers, and Akebono pads until I saw the larger size available.

Good pointers on the hub, wheel bearings, and dust shield... I didn't think about those items. I could do them as well, but I think my wheel bearings are still doing just fine.

If I am going to do it, now is the time... Just not sure if its actually worth the trade off at this point as I still have a full set of functioning 16s, plus I like my sidewall fat... this is a heavy use off-road use truck so not sure if brake fade is really an issue for me... I dont race around or drive it like a trophy truck in the city either.

If the performance difference is "night & day" ill consider doing the upgrade... just trying to get some real world input so I can make an informed decision.

As you mentioned, there is more to it if you want to do it right. I will research those items and see if its worth the risk/reward of downing them now or later... I try to do all the work myself, so its just a time penalty.

 

[Morphyne]

Ha ha! Yeah you down that rabbit hole for sure.

As far as the effectiveness? I don't know if there is that big of a difference as trucks using the 319 mm rotors use the same pads as the 338 mm rotors. but there are two diff sizes for a reason. Bearings are not hard so no need to replace just because. so that'll save you $350.

Now its just a matter of cutting, bending or replacing the dust shields.

If it was me and this thing gets heavily off roaded I am thinking the upgrade would be merited. but I'll let others chime in.

 

[luke87gt]

It would be interesting to know which models/years had which rotor?

And do the two different rotor sizes use the same caliper?

 

[Morphyne]

It would be interesting to know which models/years had which rotor?

And do the two different rotor sizes use the same caliper?

the sport model and the GX-470 has the bigger rotor and caliper. I think the limited and sr5 use the smaller ones.

 

[luke87gt]

how does the "bigger" option compare to 5th gen?

 

[Bumbo]

It would be interesting to know which models/years had which rotor?

And do the two different rotor sizes use the same caliper?

There are 319mm and 338mm sizes for both the caliper and rotor, so both would need to be changed.

Based on my reading for my year at least, the SR5 which is what I have, came with 319mm. The Limited came with the larger 338mm.

And it looks like the Sport came with both sizes depending on its trim/package and some had 16" and 17" rims... but I dont know for sure.

 

[Bumbo]

how does the "bigger" option compare to 5th gen?

Great... now I get to start all my research over again.

No idea the differences, I would have guessed it was just the 338mm, but the RockAuto rotor part # between the 5th Gen and 4th gen is different.

Hopefully someone else here can chime in.

 

[luke87gt]

Id like that cleared up as well.

My understanding is that any 4th gen can have 5th gen front brakes by swapping in the 5th gen front rotors and calipers (the 4th gen and 5th gen brackets are the same)

But if some 4th gen already have the bigger brakes, then what's the point?

Are the larger 4th gen front brakes and 5th gen brakes different? If so is it the caliper piston size or something else?

Can someone please clarify ?

 

[riceandpho]

so far in that brake upgrade thread, i can see that the 5th gen caliper piston is bigger than factory by couple of mm.

 

[Morphyne]

The biggest advantagr for going to the 5th gen upgrade is the hope that they did something in the design to fix the seizing issue.

 

[luke87gt]

This "seizing" issue is front or rear related?

 

[Morphyne]

front

 

[Offcamber]

I was in the same spot a month ago. I have an SR5 that had the smaller 319mm rotors. I replace the rotors and calipers with the 5th gen parts. It only took a little massaging of the dust shield with some channel locks and everything mounted up perfectly.