pull/shake when braking

[RatLabGuy]

On one hand this seems simple, but am curious about it.
My 4runner pulls to the right when braking, and the wheel wants to spin with it. Ir only does this after awhile of city driving - for instance just going to work and back (90% highway, little brake usage (assuming good traffic!) it dosn't really do it, and if so not 'till the very end.
Most obvious guess is, air in brake line, front left tire, takes awhile to get worked all together and compressed.
What puzzles me, though, is that there is also a bit of a shake in the steering wheel when stopping, that dosn't appear until around the time it's pulling also. Not bad, but definitely noticeable, kinda like a warped-rotor feeling, as I slow to a stop. Shake never appears when first driving etc.
If that were from a warped/thin rotor (I know they are thin)m shouldn't it do it all the time?

 

[wbcarver]

Check your brake fluid.
I will bet it is dark and contaminated.


Air doesn't usually just get in the lines all the sudden.
Unless you have run the M/C dry or had the system open.

It sounds like a caliper sticking.
What is happening is it is getting hot and the contaminated fluid doesn't dissapate the heat as it should and is expanding and putting pressure on it.



You might get lucky and find the caliper slides are starting to stick, but although common on GMs, it is somewhat rare on a Toyota.

You are probably going to wind up replacing calipers and PLEASE flush the brake hyd system (both front & rear) when you do.

 

[Ridgerunner]

The pulling might be from a stuck caliper on the other side.

The shaking is most likely a warped rotor. I would get the rotors turned and check the calipers. oh and new pads

 

[rockcity]

I'm having the same problem on my F250. I believe a new set of pads and a good turn of the rotors will clear that right up.

Rob

 

[RatLabGuy]

Well Bil lwas on the money.
Just looking into MC bottle it didn't look too bad - but when I used a 60cc syringe to suck it out - wow, like ginger ale. The crappy old yellow bottle hides it well.
Bled all 4 tires - nice and dark too. Front calipers look okay, I'll try 'em for awhile anyway. Rotora are definitely thin, hoping to replace soon.
Which reminds me, any suggestions for "upgraded" rotors for 80s IFS 4Runners, anybody? Seen FJ40s used, but that's for solid axles. Might upgrade the MC too, its leaking at the bottle.

 

[wbcarver]

If the rotors are thin and warped, you have a pretty good bet on the shake.

Like RIDGERUNNER said, a pull is usually the OTHER side sticking.

Classic scenario - a slight pull to one side while driving and a harder pull to the other side when braking.

One side is sticking (not releasing) giving the slight constant pull and the other (not sticking) is doing most of the work when you brake.

Both will lead to premature warping of the rotors.

Toyota front brakes are over built to begin with.
Not that an upgrade isn't a good idea, but if you aren't running big tires or pulling heavy trailers on a regular basis, the factory brakes brought up to snuff will give you good service.

HTH

Oh, BTW -
Even though I am sure opinions will vary. I like to use mid-grade pads. Cheap pads are - well how can you recommend cheap brake parts?
And the top of the line super hard uber lifetime pads are designed NOT to wear out. Often the are so hard, they tear up the rotors.

Just my 2¢

 

[91yota]

factory brakes should be fine... toyota calipers are fixed mount so it couldnt be a sticking caliper slide... bleed the entire system, turn/replace rotors as needed, new pads... should solve your problem completely

fj rotors are used on solid axles because the factory solid axle rotors are non-vented and the fj ones are vented

 

[RatLabGuy]

I'm just looking for upgrade b/c of larger tres w/ steel rims - currently just 31s but hope for 33s by thsi summer.

 

[Ratman]

Mines on 33's with stock brakes all around. It will lock all 4 with reasonable pedal effort. The trick to those is bypass that variable valve in the rear. Replace it with a willwood single line adjustable. I took and replaced the T on the r/f famerail with a elbow, ran a new line to the rear flex line. Bled everything out and viola! good solid brake that actually use the rear. The willwood is under the rear, a bit of a pita to adjust but its not like you adjust it ofter anyway.


edit. Also the r/f runs a line to that variable valve as well, a problem with that valve could/can cause a pull to left that "flattens out" after about 50 feet.

 

[RatLabGuy]

Hm, thank s for the tip Ratman.

interesting, yesterday I switched back to my 235s; the 31s are worn funny and ride rough, and this'll give me better MPGs for now uuntil I upgrade for real later.
Anyway, the pull and shake was still there although not quite as bad aafter bleeding all around - did not change calipers/rotors yet. Interestingly, though - it did not happen at all today w/ the smaller tires....

 

[Ratman]

Hm, thank s for the tip Ratman.
interesting, yesterday I switched back to my 235s; the 31s are worn funny and ride rough, and this'll give me better MPGs for now uuntil I upgrade for real later.
Anyway, the pull and shake was still there although not quite as bad aafter bleeding all around - did not change calipers/rotors yet. Interestingly, though - it did not happen at all today w/ the smaller tires....

Mine will get a little darty under hard braking with the 33's and my rotors are about as flat as a stripper with a 10,000 dollar chest. When I did the bypass and actually put the rear to work my high speed braking vibration reduced by over 50%.


I've also seen some wierd shit from radials tires under both braking and accel, pulls, shakes etc...

 

[upnover]

Everything Bill said X2 plus, I would change both calipers, not just one. If the rotors are thin I'd change both of them also. What difference in the wheels between the 31's and the 33's? might be some cooling difference in the two wheels. I know for sure it'll take less pressure and build less heat with the smaller tires. the stock stuff and the 33's should be fine. I don't see a need for an upgrade yet