3mm. And I was actually goofing to do a brake check and clean out that area next weekend. I though there had been some 5th gen calipers seized. If not great. Looks like a viable upgrade. I honestly was thinking in terms of better performance.
The 5th gen upgrade is looked at as eliminating the problem of seizing. Thus far, it seems to do this. As far as better braking performance, even though the pistons are larger, I still haven't seen objective data to support this. Those who have reported better braking appear to have had their brakes toasted before the swap, so anything is going to feel better, IMO.
IMHO the seized caliper is an exaggerated problem. No doubt it happens but I don't see it as a pervasive problem. Yes, mine seized at 114,000 but what's the life expectation?
Good point and I agree. (reminds me of the HG "problem" in that it doesn't happen to all of us with V6s) I'd like to know what the life expectancy of the calipers are too. Sometime I just assume that this wear and tear item is going to happen and we should deal with it (those of us in the rust belt). That's fine. If changing to brakes that are more resilient to getting seized, then I think its a good option.
Our dealership has replaced calipers on newer Toyotas, including the 4Runner for seizing. It's not super common, but it does happen.
I also have seen one or two 5th gens with Les Schwab calipers indicating they seized and were done there (ironically those, like a lot of aftermarket ones seem to seize faster).
No doubt it happens, I was trying to point out that this happens more with 4thgeners than the 5th. I wish I could post figures on this, but I can't. Again, I don't think the 4th gen is PLAGUED with this problem, but when it happens to you, you want to make sure it's doesn't happen again. I know many aftermarket offer "lifetime" warranty, but what's the point if you have to do it over and over? That would aggravate me to no end.
EDIT:
I bought my truck from a moderately salty environment (mountains of NC). 3 of 4 calipers were frozen.
I swapped 4 calipers and 4 rotors out. Less than a year later I had a rear caliper freeze again!
I swapped all 4 corners to 5th gen brakes and now live deep in the heart of the rust belt.
I am basically a rolling experiment.
As [MENTION=66389]BlackWorksInc[/MENTION] and some others have stated deep in that 5th gen caliper swap thread, and also above, that they are seeing 5th gen calipers sieze. This started this past winter, I believe?
That chilled me because I really don't want to keep swapping these bad boys out annually forever (although I have it down to a science, I just hate painting them).
For the record I'm at 1.5 years on the 5th gen calipers, so my fingers are crossed.
It is always the inside lower piston on the front that siezes first, although one of my fronts had 2 or 3 frozen pistons. So to me that is where that salt spray is like a pressure washer bathing everything.
I just wish someone would create non steel pistons so we could upgrade them. It would literally take 10 min to swap those out and I truly believe the problem would be solved.
Fingers crossed! (5th gens definitely have better stopping power too, btw!)
Urrghhhh. Well, I wish you luck. I still believe the 5th gen upgrade is still worth it. (doesn't cost more than replacing with 4th gen components via RockAuto). Better stopping power? I believe you, but I'd like to see performance specs. It wouldn't matter to me anyway, in theory it makes sense.
Question on cleaning up between the pads and pistons: What would you do? All I can think of is cleaning up any debris with a rag and spraying (silicone spray) on the pistons rings to help preserve them.............................. or am I completely wrong??? (can't you tell I'm not a mechanic ?? LOL)
