Front Brake Pulsating and an odd discovery! NOT THE ROTORS!

[NorCalBorn]

I've been fighting with my front rotors off and on for the past two years, where I end up getting some pulsating and clicking happening about 11-12 months after every repair.

I usually only see about 1/1000 of runout on the rotors, so the first time left them alone. The second time I went ahead and turned them. The third time I got fed up and warrantied the rotors for a set of Brembo rotors and Akebono pads. I replaced the hardware also, and here's where the kicker comes in..

I always prefer the Disc Brake Quiet that cures over the new lube/grease junk. Simply because I started to realize it might be a part of the problem, as I have worked on this system on easily over 100 trucks and 4Runners over the years, and this is the worst and most frustration I have had, and it is because it is my vehicle.

So after talking with someone about this stuff last night, I decided to look at things all over again, including checking the runout on not just the rotors, but also the hub as maybe the back face is off and slightly warping the rotor upon torque load. We used a dynamic check and a dial indicator set, all was good.

Hmmm, lemme check the pads and pistons, all good...aaaaarrrggghhh, why me!!!

Get this, I decide to go ahead and throw it back together and let the person I talked with do a look over in a week when he has the space to bring it in.

I grab some brake clean and clean off the hardware to put some shine on them to see if the pads are sticking and guess what I finally find?

The stupid anti-squeal lube/grease crap doesn't keep the pads attatched to the pistons so they'll retract fully and the hole that the locating pins slide through to hold the pads in have worn notches into the pins, leaving a slight edge to them making the pads catch even more, dramatically adding to the issue. In other words, where the pads move on the pin, the pad backing plate is wearing into the pins because of the freeplay instead of sticking to the pistons and fully retracting.

I went ahead and took the pins and cleaned and sanded the ledges off, coating them in anti-seize until I can pick up a new set later this week, and am also ordering some more brake clean so I can remove all the completely worthless anti-squeal lube junk.

I thought to share this with all here because I realize we all face these kind of things with our vehicles thinking all is bad and forgetting two simple things.

Check the basics before getting all the way into things.

Sometimes the newer stuff isn't always better.

*Ultimately I attribute this to the fact that the last two times I used the anti-squeal lube junk, I relaced the hardware, but didn't think to look at the locating pins for odd or excessive wear, lesson learned.

 

[dgangle]

wow, my head is sprinning now. Replace all with new, Problems go away.

 

[NorCalBorn]

wow, my head is sprinning now. Replace all with new, Problems go away.

Perhaps I was unclear, yes, I did replace with all new the last two times, and the problem did temporarily go away, only to resurface again within 12 months because of the pads not retracting fully and creating worn notches in the locating pins the pads ride along. Using the proper type of disc brake quiet that will cure and keep the pads attached to the pistons is the solution, just as it was on a Chevrolet truck I have done work on.

 

[KLF]

Is this the stuff you're talking about that you used to use? I use this with every disc brake job between the pads and pistons, seems to work well.

 

[toy4xfun]

all i use is a very thin layer of moly.

 

[raydouble]

I use nothing on the back of the pad, I just get good pads with the plates on the back...never had an issue like this.

 

[KLF]

I have no idea if the red goop helps or not, a guy that I trust in a repair shop recommended it to me once, said they get a lot less come-backs when they started using it on every disc brake job. He also said it's important to get good pads, cheap ones will wear out fast and will squeel.

 

[toy4xfun]

when i was working at sears auto, the high metallic caused a lot of brake noise, they have better pads now.

 

[NorCalBorn]

*From a duplicate thread on UY..

The pads don't necessarily have to stick to the piston - don't you have the little "v" shaped spring to spread the pads? If you found worn parts then great, but I'm not convinced it had anything to do with what you used on the back of the pad.

I just looked at the parts info and I am gonna be ordering (2) #47748's (pins). The last time I ordered the hardware for that number, I did get the cross shaped plate spring but did not get the v-springs as a part of part# 04491, and it looks like I am also missing part# 04947.

Now, I have never seen a 4Runner or Truck with these ever on them, but also have never touched a fresh/new 2nd-Gen 4Runner, so it seems that it is highly likely that over time mechanics would be skipping these parts either through omission or lack of availability through the service writer knowing about needing to order them.

I'll post up the current part#'s and pics later on.

*Thanks!

 

[Bogo]

I was never able to get the spreader springs from parts places without ordering. Always had to go to Toyota.

 

[NorCalBorn]

I was never able to get the spreader springs from parts places without ordering. Always had to go to Toyota.

I actually had began to think about that, but we did order from Toyota the last two times, and specifically asked for the pad kit with the hardware, guess what? I just called my Toyota dealership parts guy since they're actually open until 5pm and asked him why did the kit not come with them anymore? He didn't even know that one, and had to verify I was right.

I'll post up the current part#'s and pics later on. Please post up a pic of how the "W" springs are installed so I don't screw it up.

*Thanks!

FWIW, here's what I now have for info, The "W" springs are either p# 47748-60010 or 47748-60030. The clips look to be p# 90080-40209. The pins look to be p# 90080-40209.

Who knows, maybe the reason we were taught to originally use the dry-set anti-rattle/squeal was because it was necessary if these parts were absent and the new ceramic-grease stuff is better, assuming of course that you have all the hardware intact and a parts guy who knows you'll now need them as an add-on to the older 04479‑60020 padset kit which is now replaced by the kit listed as p# 04465-35061 .


Ahhhhhh, progress, gotta love it??

I just looked things up on techinfo and guess what, as of '94-on the w springs are a deleted item, as in, it was something that wasn't to be replaced as the engineers felt it apparently redundant and unnecessary, go figure.

I went back and compared my ERM's for both the '89-'93 and the more current '95, the early manual has the spring shown in the repair pic, but the newer one doesn't.

Maybe you don't need the springs if you just go around and only drive about 6,000 miles a year doing groceries, but apparently I am exceding the intended use of my automatic 2wd?

Thanks for the help with the replies here, and also to those friends over in the UY post. I'll get this all fixed and post a follow up later this week if all goes well.

 

[ntsqd]

The pins aren't supposed to be guiding the pads, they really don't even need to contact the pads - just be there to keep them from bouncing out of the caliper. So I'm guessing that in addition to the worn pins and missing hardware the calipers are worn where the pad backing plate *should* be making contact. Which is allowing enough relative motion that the plates can wear on the pins.

As to the pad spreader spring, the FJ60 calipers and pads that I recently put on my '84 Xcab vented rotor dealio) came with a bag of hardware that included those springs with the pins.

 

[NorCalBorn]

I guess it's time to follow up on what I ended up having done. It seemed to me the first step was to replace the unknown master cylinder with a new factory one, not cheap, but in my eyes, an investment none the less.

Now, apparently the new master cylinder's are coming out with a reinforced ribbing along the right side, so what is done is the raised lettering is now on the bottom, and there is this blue inked logo in main view instead.

So, since at this point the last set of rotors had already been turned once and I wanted to just have an all new setup to have it all inline performance wise we used some Centric Premium ready to run finish rotors, who is a supplier Toyota sources some of their parts from and worth the shot as Toyota endorses their use. This link show's the milling and finish these get: http://www.centricparts.com/index.php/products/drums-and-rotors

*Just to be clear, these things are pure glass, but even better, someone here, who goes by Corax kept pushing this type of tech on me. One of the referred info points was from from a company called Stop-Tech, well, guess who owns them? Centric!! :thumbup: I had a set on my Celica and loved them, I'll post a review once I have 10k on them.

Combining with the factory theme at this point, we also went with factory pads, since they are always a solid decision, also no ceramic anti-rattle grease, used the correct shims and stuff instead.

 

[NorCalBorn]

The next thing is while it was all apart, the spindle, bearings, etc were all inspected, degreased, fully cleaned, and finally re-greased and put back together to spec.

The system was fully pressure flushed, to get anything and everything out, including any possible debris in the lines.

It stops on a dime now, and FWIW from what I have seen and was confirmed is that the factory drum adjusters are worthless for anything self-actuating, as I have adjusted them twice myself in the last 6 months, including inspection of the entire system and as they're factory new still, including the anti-seize still being clean.

Apparently the best idea for hard usage is whenever I rotate the tires, usually anywhere from 6k-10k, is do like the dealership does and adjust them by hand.

The e-brake's adjusted so there's no drag, and for the first time since I have had my hands on a customer's new purchase, it goes to full activation in only 5-7 clicks.

Rock solid in my eyes.

Many thanks to Larry and his crew at Yodaman, for without them I would have been having to utter some great expletives and get really frustrated instead of getting to go out and spend an afternoon enjoying the first decent weather in two weeks with my wife and child.

 

[NorCalBorn]

*Saved for future review, pics, corrections, impressions.