Crummy brake pedal feel question

[bandman659]

First off, I'd like to state that, while I would like to do it, the Tundra brake upgrade is not on the table. Beyond the new brake parts, I would have to get new wheels/tires, and that's not going to happen.

MOVING ALONG....

The patient in question is my 2000 2wd SR5 with right at 208k on it. The problem is twofold. It has a low/soft pedal under braking at all times. It firms up and holds solid when the engine is off, so it doesn't seem to be the MC. When I'm driving, it feels like the pedal has to travel a mile before it will grab. Once it grabs, it seems to feel alright at low speeds.

At highway speeds (50+ mph), it's a different story. When braking from highway speeds, it feels like the front end is going to fall the hell off. Heavy, heavy vibrations, but the weird part is that I don't feel any of the vibrations through the pedal. It seems to all come through the steering wheel. I know it's probably just the usual warped rotors, but not feeling the vibes through the pedal makes me wonder.

I replaced the front brakes and rotors about 25k ago and the pad thickness is still good. I used Centric Posiquiet pads and Centric Preferred rotors. The vibration went away for a while, but it came back pretty soon after. The rears haven't been touched in at least 130k miles, but they still had life when I put a new 3rd member in (bad front pinion bearing on the original) about 10k ago. I just bled the brakes through tonight and it feels no different. Still long travel, still shakes like an alcoholic going through the DTs braking from 50+. Could the soft/low pedal just be from my rear shoes being out of adjustment? I use the e-brake all the time, so the auto adjuster shouldn't be frozen up, right? Could it be a wheel cylinder going south in the rear?

I love my 4runner very much, almost as much as my wife and kids, but the brakes are just a constant pain in my butt. Maybe I can find a set of 16" wheels and tires on Craigslist or the classifieds here for a reasonable price and I can put 231mm Tundra brakes on, but for now I have to work with what I've got.

 

[86SupraMKII]

Warped rotors at 25K on them seems strange, but it's possible. Did you bleed the brakes when you replaced everything... as far as the spongy brake feeling? I read somewhere that you could possibly have bad ball joints if the front end is feeling loose under braking. I haven't replaced my ball joints yet, so I don't know if this is a problem in your case. Maybe jack the front up and wiggles the wheels / tires around to see if there is any wiggle on the lower ball joints. Anyone else have any ideas?

 

[BlackCat914]

If your rears are very out of adjustment and not doing much, you're putting all the burden on the fronts, which will obviously generate more heat and cause warping sooner. Drum brakes have a lot to do with pedal height, so adjusting them will probably bring the pedal up quite a bit.

 

[bandman659]

I considered the ball joints, but my tire wear has been perfect. 70k on this set of Michelin LTX M/S. Wouldn't worn out ball joints cause wonky tire wear?

 

[bikerjosh]

I still think you might have air in the lines somewhere. It takes a ton of bleeding to clear it out. Might be more than one issue leading to the brake issues. just my 2 cents

 

[Dous]

You could have easily warped the rotors in 25k, especially if they weren't OEM.

I bought a set from Autozone, before I knew about the TBU, they warped in less thank 6K miles. But it is also possible the rear drums are warped, mine were too, from overheating. Someone left the parking brake on for miles on end, and that caused a wicked vibration when brakng

 

[highcountry]

You could have easily warped the rotors in 25k, especially if they weren't OEM.

I bought a set from Autozone, before I knew about the TBU, they warped in less thank 6K miles. But it is also possible the rear drums are warped, mine were too, from overheating. Someone left the parking brake on for miles on end, and that caused a wicked vibration when brakng

My daughter's '96 had the infamous brake shudder so I replaced the calipers, rotors, and pads and I had a warped rotor right out of the box, new. This was before I knew about the poor design of 4Runner's front brakes. One of the reasons that I sold that vehicle.