I just did the tundra brake upgrade on my 99 4runner and absolutely can't get the pedal to feel the way it did before the upgrade.

The pedal is very soft and I think it's just a lot of pedal travel, maybe a little spongy as well. I have bled the brakes twice myself and had my mechanic do it twice as well since I didn't think I did it right but still the pedal feels too soft.

Anyone else have this problem and how did you fix it?

 

But how does it stop?

:wabbit2:

 

It stops good when I actually get the pedal down far enough but every time I go to engage the brakes there's an "oh crap I don't have brakes" moment for a split second in my head because of the long pedal travel. To me this isn't really acceptable.

 

How did you bleed them?

Bleed them a few times with the wheels on. This way, the rotor won't flop around and the last air pockets will be easily forced out. That or you have a bad M/C; Tundra calipers displace the same amount of fluid as 4Runner calipers.

 

I bled them with the wheels off but I'm pretty sure my mechanic did it with the wheels on.

The M/C has not been bled though... any chance air got in there?

 

if you really think you bleed them right try one of these
.Wilwood Disc Brakes 260-1874 - Wilwood Residual Pressure Valves

http://www.summitracing.com/parts/WIL-260-1874/

 

I had the same problem when I first did my Tundra Brake swap. I simultaneously did rear brake extension and braided lines all the way around. Due to the longer length of brake line and the fact that I needed to bleed them a few times yielded in a sloppier pedal but INCREASED braking abilities.

 

So did you ever get the pedal back to normal or just left it like that? The braking does seem very good when I really get on the pedal but it still bothers me a lot.

 

I only noticed a small difference, after a while one of two things happened; I got used to the new feeling, or it eventually went back to normal. When I'm talking a very slight slop in the pedal, nothing extreme enough for me to feel cautious while driving

 

If you let the reservoir go dry at all while bleeding, that will allow air into the M/C. Then you need to bleed the M/C, and then re-bleed the wheels again. It's a double chamber reservoir, so there is not much fluid in each half.

 

I'm fairly certain I did not let the reservoir get too low.

I had a friend over today to help me and we bled the brakes again and again, just to be sure but it did nothing.

I'm now certain that it's not spongy brakes but just very long brake pedal travel as the truck stops very well when you get the pedal down far enough and it doesn't feel spongy at all really.

What could cause this? I've read conflicting info about the volume displaced by the tundra calipers. Some say it's the exact same as stock 4runner calipers and some say it's more. If it's a lot more I could understand the longer pedal travel but it doesn't seem like anyone else is having this problem after the upgrade. Btw, I also put on the smaller tundra calipers if that makes any difference.

Reading up on other causes for this it seems a common cause is that the rear drums need to be adjusted but I have done it probably five times now and I don't see how I could be doing it wrong. My rear brakes do suck as I can barely get the truck to stop by pulling the ebrake and with it fully engaged, the truck will move with just a tiny bit of gas which seems too easy. I tried adjust the rears to the point where I can barely turn the wheel with my hand (everything I've read say to adjust them to the point where the wheel will spin one revolution before stopping, so this seems more than adequate.)

Either way I'm taking it to a mechanic tomorrow to try and fix it but I'm worried that he's just gonna blame the new brake parts since they're not meant for the 4runner and not really want to troubleshoot it.

 

if you have the Type A 199 mm calipers, the volume displaced is the same. But if you have the Type B 231mm calipers, then it has a bigger displaced volume than the 4Runner calipers.

 

I do have the 199mm calipers so it shouldn't be that then.

 

Did you ever get your brake petal up???

 

Yes I did actually. Turned out the rear brakes needed to be adjusted. I'm not exactly sure how that was affected by the new front brake components. Maybe something to do with the different overall displacement of brake fluid or something? Either way, another mechanic adjusted the rears and that took care of it.

 

good update!

 

I've been battling with the sloppy feeling pedal after the Tundra brake upgrade and I haven't found any official solution posted on line, so here is my fix to all of you dealing with a sloppy pedal after installing the larger Tundra calipers (231mm?)

I have a 2000 4runner 5spd manual, and I did the Tundra brake upgrade. The result was disappointing in the sense that my pedal travel increased, almost as if I had air in the lines, but I know I didn't. Because I used the larger 231 calipers, the stock 1" master cylinder was not sufficient. I found out that the last generation of T100 trucks, I believe 97,98 used a 1 1/16" bore master cylinder. I had to get a vacuum booster from a T100 to hook it up (because the master cylinder has 4 hose bolt pattern, instead of 2), but the result is a much firmer pedal - perfect!

 

I am about to do the Tundra upgrade to 231 mm. I ordered the Tundra brake pad kit 04465-AZ001-TM and the pads are not the pads I have seen in other TBU threads. They do not have the full surface area that I expected and have seen in other threads. Has anyone seen this? The outer edges are cut down. Also, where does the 231 mm dimension come in? The total width of brake pad is 133 mm. Thanks.

 

I ordered those same pads. Yes, mine lacked the full surface area as well. I was crunched for time, so I used them anyway. I only paid $45 for the pair anyway, so I figured I could change them out later on if I thought they were under-performing.

I am still a little underwhelmed by the braking after the upgrade, but I haven't had the opportunity to put my boat behind the 4runner and check things out. I am having the same mushy feeling in the pedal that the OP describes. The truck "seems" to stop faster, but the seat of the pants is not the most reliable test instrument. Either way, my brakes still don't feel nearly as good as my friend's 2002 4runner. Not sure why that is.

 

Hey mocity, I just did my231mm and that is what my dealer sold me. I asked her if this are right, she said that theyare. What happen is they cchanged them a few months ago because of the price of everything is going up so they redesigned them..... That's what I had heard