Guess what I did

[Previologist]

No really, you have to guess because I don't know. The winner will win a "you guessed right" award when I visually determine what I did, which may be 6 months from now because I'm going out of state.

The facts: I drove my 4runner long after my brakes started grinding badly. Since I planned to replace the rotors next time I do brakes, and its way too bloody cold to do them in the winter, and I don't drive my rust free other Toyota in the winter because I want it to remain rust free, I just kept driving. One more week and I would have been home free.

But last weekend I was 30 miles from home and the pedal bottomed out. The reservoir was way low so I added fluid, and within a short while the pedal bottomed out again. I then noticed brake fluid sprayed all over the driver side of the car, coming from the left front wheel. Thankfully its a 5 speed so I limped home 30 miles using the engine for braking, stopped at the car wash 5 miles from home, washed the heck out of it, and drove it all the way home and into my garage without using the brakes.

I am leaving town (in my rust free Toyota lol) in a few days and may not even get the wheel pulled before I go. So I'm curious what you think happened. Remember the awesome reward/award you might get 6 months from now.

 

[pluton]

How old are the brake hoses? Mine were almost totally rigid at about 17 years after new. Replaced them then.

 

[AuSeeker]

My guess is the caliper piston got out far enough to lose the oil ring seal to the bore, thus all the brake fluid lost.

 

[Previologist]

My guess is the caliper piston got out far enough to lose the oil ring seal to the bore, thus all the brake fluid lost.

That's my guess too. I didn't know if it was possible but I may have found a way lol.

 

[Previologist]

How old are the brake hoses? Mine were almost totally rigid at about 17 years after new. Replaced them then.

They are original. I'd be just as concerned with rust given the progression of that cancer too. Will have to evaluate all this in the fall when I get back.

 

[IVD4R]

Ohh i see.

 

[s14sean]

Most likely the pads wore past the backing plate, the piston overextended, and either the caliper seal blew or the rubber hose ruptured from the extra travel. Once that happens, the system can’t hold pressure and the reservoir drops fast. Should be obvious once you pull the wheel.

 

[IVD4R]

Exactly, He needs to take out the wheels to see

 

[AuSeeker]

Most likely the pads wore past the backing plate, the piston overextended, and either the caliper seal blew or the rubber hose ruptured from the extra travel. Once that happens, the system can’t hold pressure and the reservoir drops fast. Should be obvious once you pull the wheel.

There's no way the rubber hose ruptured from worn brake pads/extra travel, ruptured from old age yes, but not from pad wear!!:nono:

 

[Previologist]

The suspense is killing me. I should be reunited with my 4runner for the first time in 6 months within a couple weeks, then I will get to the bottom of this thriller (In the meantime I bought an 04 Xterra, which is OK but no substitute for a 97 4runner. But they will reside in different states, at least for now)

 

[TheDurk]

Well, to see if it's the hose, top up the fluid and push hard on the brake pedal. You will hear the hissing from the front. And yes, you will lose some more fluid doing it. Or hitch up a pressure bleeder. I know, because my left front blew out a few miles from home last summer. 5SPD and I was able to limp her home. I had done the rear, but doing the fronts just sort of escaped me. I replaced them both.

 

[TheDurk]

There's no way the rubber hose ruptured from worn brake pads/extra travel, ruptured from old age yes, but not from pad wear!!:nono:

I agree on the travel, but maybe the vibration kicked a dying hose over the edge. I am impressed at anyone who can drive his brakes so far that the piston goes through the backing plate. If that's it, please post pics.

 

[Thumbie]

I also am guessing that the pad wore all the way through, and the piston overextended past the fluid seal.

Happened to the rear caliper of my brother's Tundra because he only ever took it to JiffyLube

 

[Previologist]

Well the exciting results are in, and we're all sort of wrong!! It does appear that the inner pistons overextended and probably caused the leak.

I haven't taken it apart yet to confirm but...what caused the overextension was not pad wear, what caused it was the inner half of the rotor disappearing itself.

Never seen that happen before and am not anxious to see it happen again. I'm not sure how it could do this without me noticing, but it did. Stealth rotor disintegration.

So now the question is what's the best easiest cheapest plan of action? Suggestions welcome. I haven't looked to see if they make rebuild kits or whether there are quality options out there that don't cost an arm and a leg and another arm. Fortunately the right side rotor is still in one piece, but obviously will need to go.

 

[AuSeeker]

Yes that would do it!!
.
I would replace everything and forget about it, buy once cry once.

 

[brillo_76]

I have rebuilt a few calipers just to see how long they would last. A few years they started to seize again so best to just get rebuilt ones or new...:-(

 

[Previologist]

any good aftermarket rotors? Don't want to skimp on the caliper so I will get a reman from Toyota, but not keen on paying 100 each for rotors on a rustbucket that probably has about 5 years left to live.

 

[AuSeeker]

Look on RockAuto and pick any of the ones that has a heart next to it, those are the most popular ones sold.

 

[gomiami]

Yes that would do it!!
.
I would replace everything and forget about it, buy once cry once.

I second this. Replace everything - calipers, pads, rotors, shims, fit kit if aftermarket. Have some proper brake grease on hand since half the time the stuff you buy aftermarket may not be adeuqate. I bought a pair of reman calipers and one slide pin was dry. That would have been a waste had I not checked.