Figuring out this brake problem?

[Ghostface80]

I have a 2003 SE 2WD that I just picked up a month ago with 68K miles. The truck is great, except for a few proglems, the largest of that being the feeling of the brakes. The previous owner took the brakes to Pep boys to get his brakes done a few months back, then went again to get his rotors resurfaced because the brake pedal steps in further than normal and after the brakes get hot, the feeling of the brakes becomes more unpredictable especially at slow speeds


I read a big thread on how our 4runners might have a rotor problem and how many owners are getting a "pulsating" (uneven) feeling when braking even after getting there rotors resurfaced with new pads. I'm not really getting this except after the car has been driven for a while and at slow speeds. I'm not sure if it's the exact same problem.

Any recommendations on what to do? Thanks for the help.

 

[Koz]

Complete brake job (front), rotors, pads, have the front calipers rebuilt and flush the fluid (OEM parts only). Do it right and walk away or keep on playing with it!

Koz

 

[Ghostface80]

Completely new rotors? Should I avoid resurfacing in the future? Is this a regular thing with our 4runners? sounds a bit excessive..

Read up some more, and found it could possibly be a leak from the Master Cylinder? Just seems odd as Pep Boys couldn't find anything wrong. Hopefully Toyota will if it comes to that.

 

[Northof49]

Pep Boys eh.....I would guess they used some combination of aftermarket rotors/pads/calipers/crappy installation that's leading to your symptoms.

It's not a 4Runner thing.....any brake rotors in the world can be cooked in 5,000 miles, let alone 68,000. I would bring it to a reputable dealer/shop and get their opinion on it before throwing money at it tho.

 

[greasefingers]

My Toy FSM states the run-out should be 0.002

 

[TeCKis300]

Koz hit the nail on the head.

There are too many unknown variables in your brake setup at this point. Completely replacing the rotors, pads, shim/fit kit, and flushing the brake fluid with all OEM is the only real solution. Do it once and be done with it for another 40k+ miles and piece of mind.

Resurfacing the rotors removes heat sinking mass which is important to keeping peak temps in check. Also, pep boys more than likely did not put the "shim kit" back on the back of the pads which allow them to transfer more heat into the brake fluid via the brake caliper piston. You may also have air in the lines all which contribute to the compromised brakes when they get hot (brake fade).

Brake are simple...but must be maintained properly. I very much doubt it is the master cylinder at that mileage.

 

[00328]

I believe there was a thread or two about bad master cylinders awhile back and it might have involved '03s. Not completely sure though. Try a search.

 

[toybox]

Completely replacing the rotors, pads, shim/fit kit, and flushing the brake fluid with all OEM is the only real solution.

I would agree except for the OEM rotors. They SUCK and if they are a problem to begin with (like on mine) why would you want to put the same product on. I am not the only one with problems with Toyota's rotors either.

 

[TeCKis300]

then went again to get his rotors resurfaced because the brake pedal steps in further than normal and after the brakes get hot, the feeling of the brakes becomes more unpredictable especially at slow speeds

To test if it's the master cylinder...get your car and brakes hot...then go to a parking lot. With the engine still running...step on the brake firmly and hold it there with a constant pressure. If the brake pedal is initially firm but starts to sink, it may very well be the master cylinder.

 

[pipspeak]

In my experience resurfacing rotors is a waste of time. They'll be fine for a few months then get warped again. It's happened to me on many cars in the past and must be either because the rotors get thinner (even a fraction of a mm makes a difference) or that once they've warped the metal's going to keep warping (also a possibility but I'm no chemist). My advice is don't bother.

Also, if your rotors are good, be sure to go very gentle on the brakes for a couple days when you get new pads. Until the pad surface has started to wear they often heat up quicker and can lead to brake fade and warped rotors. Hard braking down a hill with brand new pads is not going to do your rotors much good, as I also learned.

 

[flyboykg]

Koz hit the nail on the head.

There are too many unknown variables in your brake setup at this point. Completely replacing the rotors, pads, shim/fit kit, and flushing the brake fluid with all OEM is the only real solution. Do it once and be done with it for another 40k+ miles and piece of mind.

Generally speaking, and I know this will vary from region to region, dealer to dealer, but approx how much would this cost to do, all @ once? I am having the same "pulsing" braking at slower speeds, and I guess I should just do it, but need a general idea, so that I can break the news to my wife My local dealership service dept is closed for the day, or I would just call them.

 

[Ghostface80]

Re: Re: Figuring out this brake problem?

To test if it's the master cylinder...get your car and brakes hot...then go to a parking lot. With the engine still running...step on the brake firmly and hold it there with a constant pressure. If the brake pedal is initially firm but starts to sink, it may very well be the master cylinder.

Thanks! I'll try that later today.

 

[Ghostface80]

I would agree except for the OEM rotors. They SUCK and if they are a problem to begin with (like on mine) why would you want to put the same product on. I am not the only one with problems with Toyota's rotors either.

Then which rotors did you go with? Everyone seems to recommend OEM.

 

[TeCKis300]

Then which rotors did you go with? Everyone seems to recommend OEM.

Definitely go OEM. Do NOT get aftermarket or crossdrilled/slotted. These will warp quicker. Very few aftermarket rotors are truly better.

 

[KMX3060]

Re: Re: Figuring out this brake problem?

To test if it's the master cylinder...get your car and brakes hot...then go to a parking lot. With the engine still running...step on the brake firmly and hold it there with a constant pressure. If the brake pedal is initially firm but starts to sink, it may very well be the master cylinder.

This "test" you describe is only useful with the old style vacuum booster brakes.

Our system is a servo system and not subject to vacuum or vacuum diaphragm leaks. This is not your fathers oldsmobile.

 

[TeCKis300]

Re: Re: Re: Figuring out this brake problem?

This "test" you describe is only useful with the old style vacuum booster brakes.

Our system is a servo system and not subject to vacuum or vacuum diaphragm leaks. This is not your fathers oldsmobile.

Testing the master cylinder should be the same whether it is boosted by vacuum or electronic assisted brake booster no? What do you suggest?

 

[toybox]

Then which rotors did you go with? Everyone seems to recommend OEM.

Haven't changed mine yet but aftermarket are much cheaper than OEM (I don't a brand yet, Bendix maybe).
Again I'm not bothering with OEM rotors that warped within 10k, how much worse can aftermarket be?!?

 

[DanDLT]

did you find a solution to the pulsating brakes?
i just changed rotors and oem pads and still doing it..
i bet its the calipers..

 

[LandShark]

I replaced the front rotors with Bendix and used OEM pads. Have about 8000 or so miles on the new rotors. No problems yet. I know it isn't a lot of miles so I will just have to wait and see!!

 

[Ghostface80]

I also replaced my front OEM rotors and pads and the pulsating went away, but just like Landshark I only have a few thousand miles on mine. On another thread.. I think someone fixed the problem by swapping out the rear rotors and pads.