Pulsing feeling during braking

[audiness]

2003 T4R 4WD V8
80K miles

So lately I've been getting a pulsing feeling from the T4R during braking. I am thinking warped rotors or possibly a stuck/frozen caliper since it seems common on the 4th gens. So I take the front brakes apart, calipers are all rusty, some of the pistons seem REALLY rusty, so I just say screw it, go to see my buddy at Napa, get both brand new front calipers. Took the rotors to a local shop, the guy said they are within spec and turns them for me. So I get it all back together, new caliepers on, pads still have plenty of meat, bleed the system, clean all parts with brake cleaner, etc.

The pulsing is still there!!?!?!:wtf: Should i look at the rear brakes possibly? Just hoping to get some suggestions from some fellow T4R owners.

Here's a pic of the old and gross brakes, and the new setup, just cause i know everyone likes pictures.

 

[Ian]

I have pulsing on my 04 SE, which I think is coming from the rear rotors. I replaced the front like you and it was still there. I've been meaning to burnish the rear rotors, but haven't had time.
In case anyone is wondering, Burnishing puts a nice finish on the rotor without the usual mass loss associated with "turning rotors.

 

[bigwebb83]

you need to have them turned while on the car. If you have them turned off of the car your not taking into account any imperfections ON the car itself.

 

[DC Dude]

Master cylinder issues?

 

[GAshawn22]

I had this happen on my 04 T4R that I put 125k on a few years back. It all started when I was offroading one day and hit a bump/pothole while braking (probably going a little too fast). I had the rotors turned then replaced because it was driving me crazy. Was fine for a while until I had to brake moderately hard on the freeway about three days after getting them replaced and it was back. I'm no mechanic, but I think whatever the rotors are actually attached to was bent slightly so no matter what they would forever become warped. It lasted the next three years until I traded it in and voila no more pulsating while braking.

Perhaps someone more mechanically inclined can add more insight but let me say I can totally empathize with you!

 

[Athabasca]

I fixed the issue by first installing 1st gen tundra rotors and calipers (search tundra brake mod) and then installing stop tech stainless brake lines.

Much better braking all round.

The ABS seems to pulse through the crap rubber brake lines.

 

[12guns]

Brake deposits can also build up unevenly and cause "pulsing". But turning the rotors should fix build up or warped rotors...not sure why you're still having problems, but one theory is this, the rotors could have been warped or have build up...they were probably fine right after you reinstalled them, then after driving a bit, they started pulsing again?
If so, your pads have now left uneven deposits causing the "warped" feeling. Most brake pads have a break in coating to minimize leaving uneven deposits, but if you used your old pads, that coating was long since worn off. Sounds crazy, but if you google "brake pad deposits" you'll find all kinds of stuff.
It can happen especially if you brake hard or tow heavy loads. I would but if you turned the rotors, put NEW pads and properly broke them in, you would not have the same problem. Hope that helps!

 

[bshuffleboard]

a frozen caliper would cause lockups, not pulsations. with 80k miles, if you have replaced the rotors yet, i would just replace em. its definately the front rotors that are warped. get new pads and rotors. be done with the problem. if you had 40k miles, i would suggest turning them. replace em though. and that dude was right about using an 'on car lathe' to turn them.

 

[kai920]

I would think that if you can also feel the pulsation it in the steering wheel its up front, if not then probably coming from the rear.

 

[Ian]

I usually take everything I get from a Toyota service advisor with many grains of salt, but I'll throw this out there as a data point. He said the OEM Toyota pads leave uneven deposits on the rotors and that's why the 4runner "has a common problem with pulsing." He told me this when I had my front calipers replaced under warranty (extended). He suggested that I replace the pads with a different brand, which I thought might be telling considering he is a purveyor of Toyota parts. My plan is to burnish the rotors when I have time and see if that fixes it. If it comes back shortly, then I'll replace the pads.

 

[DocMT]

I usually take everything I get from a Toyota service advisor with many grains of salt, but I'll throw this out there as a data point. He said the OEM Toyota pads leave uneven deposits on the rotors and that's why the 4runner "has a common problem with pulsing." He told me this when I had my front calipers replaced under warranty (extended). He suggested that I replace the pads with a different brand, which I thought might be telling considering he is a purveyor of Toyota parts. My plan is to burnish the rotors when I have time and see if that fixes it. If it comes back shortly, then I'll replace the pads.

Your Service Advisor is a smart man. He's 100% correct. The OEM pads are likely to leave uneven deposits on the rotor surface. This is true on the rear rotors as well.

My guess is that the OP is having that exact issue on his rear rotors. Cure the rear rotor issue and the problem should be gone.

 

[audiness]

Thanks for the replies everyone, I will probably try a new set of pads, and if that doesn't do it, I guess it will new a new set of rotors after that. The pads leaving deposits on the rotors sounds like it might be the culprit.

when it comes to brakes, I spare no expense, I want this vehicle to be 100% safe for my family.

 

[DocMT]

Thanks for the replies everyone, I will probably try a new set of pads, and if that doesn't do it, I guess it will new a new set of rotors after that. The pads leaving deposits on the rotors sounds like it might be the culprit.

when it comes to brakes, I spare no expense, I want this vehicle to be 100% safe for my family.

You'll most likely have to either resurface the rear rotors or buy new ones to get rid of the pulsation.

Give Raybestos ceramic pads a try. I've found that they are much less likely to imprint on the rotors than the OEM pads.

 

[bigwebb83]

I had this happen on my 04 T4R that I put 125k on a few years back. It all started when I was offroading one day and hit a bump/pothole while braking (probably going a little too fast). I had the rotors turned then replaced because it was driving me crazy. Was fine for a while until I had to brake moderately hard on the freeway about three days after getting them replaced and it was back. I'm no mechanic, but I think whatever the rotors are actually attached to was bent slightly so no matter what they would forever become warped. It lasted the next three years until I traded it in and voila no more pulsating while braking.

Perhaps someone more mechanically inclined can add more insight but let me say I can totally empathize with you!

this is why it helps to get them turned on the vehicle. it takes into account any imperfections in the surface that the rotor is mounted to.

 

[audiness]

i found a pretty good article, thought i'd share. I think i am going to try bedding these newly resurfaced rotors and see what happens.


StopTech : Balanced Brake Upgrades

 

[santana]

excellent post
thanks for sharing your experience with the brakes pulsing

my 05 v6 has also been pulsing since about 70k miles
i was due to replace my stock pads then and did only the front pads at about 80k miles
the pulsing continued

im at 113k right now and for the past two months have been gearing up to change the front rotors to see if this problem goes away. i visually inspected my rotors today and they seem as good as they were at 50k. however i did notice that from the center on out. that the rotor gradually gets thicker the closer you trace to the center ring.

i hope you post about any update about getting this resolved. im starting to believe that it has to do with the rear brakes. i might attack those first since i can see in this thread the front brakes dont appear to be the issue.

 

[ilovethedealer]

if you have a pulsing pedal only then it is the rears..

if you have a pulsing pedal and a shaking steering wheel then its your fronts..

and all this pad deposit hoobla... You get warped rotors from to much heat.. thats why trucks meant to tow have large fins in the rotor for heat dispertion

its actually better to turn rotors off the car because any deposits on the hub will cause a really ****ty cut.. and you clean the hub during brake installation to make sure the rotor doesnt warp again..

and as long as your caliper pistons go back in there is no need to replace the calipers.. waste of money, yes you did..

honestly that rotor cut looks very good and as long as they are within spec dont buy new ones..

 

[DocMT]

if you have a pulsing pedal only then it is the rears..

if you have a pulsing pedal and a shaking steering wheel then its your fronts..

Wrong. A pulsating pedal can be the fronts, rears, or both. You can have a perfect steering wheel and still have pulsating brakes in the front or rear.

and all this pad deposit hoobla... You get warped rotors from to much heat.. thats why trucks meant to tow have large fins in the rotor for heat dispertion

Wrong. Brake rotors don't warp. People think the are warped because the don't understand what's really happening when they feel pedal pulsations. The fact of the matter is that the metal isn't warped. Research the issue yourself and you'll learn the truth. And once you know the truth, you'll understand how to avoid pulsating brakes forever.

its actually better to turn rotors off the car because any deposits on the hub will cause a really ****ty cut.. and you clean the hub during brake installation to make sure the rotor doesnt warp again..

Wrong. Cutting rotors on the car will compensate for any runout in the hubs. But hubs shouldn't have any measurable runout in the first place, so if your hubs are 100% true, cutting the rotors off the car will not be an issue.

and as long as your caliper pistons go back in there is no need to replace the calipers.. waste of money, yes you did..

Wrong. The 4-piston calipers on our 4Runners have issues seizing. It happens to most of us, some sooner than others. It seems like people who live in the snow belt have the problem earlier and more often than those who do not. If the piston even begins to stick, the caliper should be replaced with a new or rebuilt unit. This is common knowledge among members of the forum.

honestly that rotor cut looks very good and as long as they are within spec dont buy new ones..

Wow, finally something you said is correct. Congrats on getting one of your points right!

 

[GreatZen]

Whew DocMT, thank you for restoring some sense to a dangerously wandering accumulation of myth.

Here's an article from the folks at stoptech regarding the brake rotor warping myth:

StopTech : Balanced Brake Upgrades

 

[zerowkul98]

I did a LOT of "replacing" a year or so ago when i thought i MIGHT have the seized caliper (which i did).

Had the front calipers replaced with A1 Carbone's and had all OEM rotors & pads installed simultaneously. (I was giving the 4Runner to my wife, so i wanted it to be 100% good to go.)

My only concern is this:

I feel my "booster" thats on the V8 braking system is kicking in TOO often. Im afraid this might have something to do witht he master cyl. or something to that effect. Im no mechanic, nor did i pay attention to any of the above for the first few years i owned the car. Its just that sometimes after i pump the brakes a few times, i hear the "buzz" from the booster and i feel the pressure in the brake pedal increase. If if at a stop and it kicks in, i can see the headlights dim ever-so-slightly when the booster kicks in.

Is this typical? Or maybe is there some warning signs I should be on the lookout for? The dealer techs that worked on the system when it was all flushed, replaced with OEM's said it all looked great.