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

[Obi..]

I'm copying a post I am making over in Mud for all here to hopefully benefit from. :D

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.


FWIW, Yes, Keith..you are allowed to smile and laugh.

[CJM]

So it was the anti-squeak spray stuff causing it or the lubricant based greasy stuff?

Im curious cause I have used both with no issues at all-BUT the spray on stuff I ALWAYS wait for it to dry before I even put the pads back on.

[Obi..]

Yep, it was the greasy stuff (lubricant) that doesn't cure that I see being the issue,
as it has never occured like this beforehand while using the spray on or curing stuff..
http://www.allbatterysalesandservice.com/prodimg/BK12.jpg

I am switching back to old and reliable since after cleaning up the pins the problem has gone away.
Basically the pads couldn't retract fully or clamp evenly causing the issue.
http://ken-co.com/crc/disc-brake-quiet.jpg
http://www.handymanlyness.com/archives/auto/repair/brakes/GM/Jimmy/mxbrfp35a_brake_pads_99_jimmy.jpg

[corax]

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.

BTW - all the goopy stuff does is dampen high frequency vibrations which cause the squeal noise, the lube prevents/reduces those high frequency oscillations from causing adjacent components from "ringing" and making the squeal noise - either way, it's only for noise abatement

[CJM]

Hmm

I have always pretty much used the spray on disc brake quiet and let dry and put on like I said earlier.

I have also used this ceramic purple goop we got at work. It doesnt seem to dry either, but no reported issues. Could toyota calipers just not like such a thing IDK.

[Obi..]

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.



Nope on the v-spring (did you mean a "W" spring, mine's not there?), just a t-shaped deal that keeps tension on the pins. Please get me a pic b/c I was thinking there might be a piece they haven't been including in the hardware kits anymore and I thought it was either that type of deal or a set of clips that go around the backing plate and slip into the piston cups for retention.

SW13 calipers in case you need a reminder.

:D

p.s. Check your snow thread fool! ;)

[Obi..]

*Corax, I looked the parts info up and I am gonna be ordering (2) #47748's. 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. Please post up a pic of how the "W" springs are installed so I don't screw it up.

*Thanks!

[Seanz0rz]

my stock 3rd gen brakes just had the t shaped plate, no spreader spring. however, my tundra fronts have a spreader spring like you are talking about.

[corax]

this is the spring I'm talking about

http://i207.photobucket.com/albums/bb56/_ritz_/Tundra%20Brakes/TundraBrake006.jpg

needs to go on the leading edge of the brake pads

[CJM]

T100 calipers have a t-shaped plate and a retaining spring for the pins onthe outside as the picture shows.

[corax]

I was able to use both on my T100 calipers - the v shaped spring and the big t shaped plate

[Obi..]

I was able to use both on my T100 calipers - the v shaped spring and the big t shaped plate


Thanks guys, FWIW I think CJM's on the right path here still and here is why..

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. :confused:

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? :spit: :angel: :wrenchin:

I have this info, I copying into my post on Mud..

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?? :clap: :screwy: :confused:

[CJM]

My T100 is a 96 and like I said I only have the outside springs and the T shaped spring piece-not that little spring.

I had front brake problems myself, but all of mine had to do with the original calipers locking up and the new ones doing the same. I replaced the once, did it again to me and locked up after sitting for 3 months. Replaced with bendix and no issues.

All of the rebuilt calipers I got had only the T piece of metal, no little bitty spring in there.

[Obi..]

All rebuilt calipers and all non factory pad kits no longer come with the "W" springs, you apparently have to order them specifically as from what I was told yesterday afternoon by Larry @ Yodaman, is along with the lag on availability, if they're installed wrong, the rotor can catch them at the center and cut the spring in half, causing more problems than they're worth, thus the eliminating of them for the later years. I have a pic now thanks to Keith. :D

On that last bit, Corax, you are running the pin tension spring on yours right? The cross "lowercase-t" shaped one? P#47748 (Refer to attached pic)??

[CJM]

Oh reminds me: Are you running the backing plates on the brake pads? I never had a set on mine at all but when I bought a set of toyota pads once he asked me if I wanted them and I tried using them only to find out they wouldnt allow me to put the pads on!

[corax]

On that last bit, Corax, you are running the pin tension spring on yours right? The cross "lowercase-t" shaped one? P#47748 (Refer to attached pic)??


i have both the "w" and the lower case "t" on - another option (what my roomie uses on his open wheel car) is a small diameter coil spring with just enough resistance to compression placed over the pad pins to spread the pads just a little bit like this:

WWWWWWWW

[Obi..]

Yep, thought of that myself, using the small diameter coil. I'll see how the "W" springs look and the pricing on them tomorrow when I pick up the parts.

[Edit]Erm..today, it's past 12am. ;)

[Obi..]

*So, the coil spring on the pad pins is not viable b/c they interfere with the fitment of the "t" spring. I was able to make the "w" spring work, but had to modify them slightly, as they're a little too long. You straighten out the "L" on the ends (which pretty much broke off) and I heated them slightly with a lighter and re-bent the "L" in so they were about 2-3mm shorter and fit properly into the tab/hole as needed.

I spoke w/ Corax earlier and am trying to understand the logic as to why he again swapped out his newer master (the 1-1/16" one) for a 1" bore instead. It looks like the idea is to have better line pressure, a better rear residual valve, and if/when I choose to finally do the SAS I can swap in the rear discs properly? What if I keep it IFS and go long travel and rear discs, same logic??

So I get the 80 series 1" master or the earlier 4Runner 1" master then, or are they the same??

I gotta trust the input I got but want to better understand this bit. In other words, sorry guys but there are some things I just don't know well enough to play with and honestly, this is something family rides in too.

Funny, I know how to go fast, and still need help when it comes to stopping? Note to self, bombing around the sand at 45+mph and the freeway at easily 70mph means you need good stoppers. :confused: :rofl:

[corax]

I went to the smaller MC because the pedal was too stiff with the 1 1/16" (couldn't fit the dual diaphragm booster). BTW, there is no rear residual valve built into any of the master cylinders that have ever been on my 4runner,when you take your foot off the pedal line pressure goes away - residual valves were used back in the 50s/60s/70s to keep very slight pressure in the system (necessary due to materials & design of the drums - not necessary for the last few decades).

a 1" bore MC is gonna be the same whether it's on an LC or a 4runner

Here's a link for ya
Car Brake Bible (http://www.carbibles.com/brake_bible.html) <- the bit about hydraulics is near the bottom

[Obi..]

*The thing that keeps coming back into mind is with Lil'Bro's he has the 1" master and ABS, but for mine it only lists the 1-1/16" as ABS, and the 1" as Non-ABS. So what is preventing me from just mounting the ABS reservoir on the 1" master, as that is the only component that is the main ABS part? I'll have better line pressure and modulation, and like I said, provided I find nothing amiss with the booster or pushrod.

FWIW..the brakes do work well, despite the mushiness, I found out today without provocation.
~Who cuts off an armored 4Runner doing 45mph with less than 200 yards clearance and had seen me, anyhow? The guy's lucky I was able to avoid him..

[corax]

If your brakes are mushy now, the smaller diameter MC will only make it worse - as far as ABS is concerned, it doesn't care what MC is on there. Maybe they used the 1 1/16" MC to provide more fluid volume that could be bled off when the ABS activates?

[Obi..]

All good I think from here on in..we'll see Monday on the drive home from the shop.
:angel:

[Obi..]

I guess it&#39;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.
http://farm5.static.flickr.com/4068/4329627916_cf3d89eefe.jpg

Now, apparently the new master cylinder&#39;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.
http://farm3.static.flickr.com/2690/4329627918_d0706389da.jpg
http://farm5.static.flickr.com/4053/4329627922_579c335abd.jpg

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&#39;s the milling and finish these get: http://www.centricparts.com/index.php/products/drums-and-rotors

http://farm3.static.flickr.com/2701/4329627908_c3de2aa1c6.jpg
*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&#39;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.
http://farm5.static.flickr.com/4038/4329627912_1da2c592fc.jpg

[Obi..]

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. :D

[CJM]

So what do you think was the issue in the end?

[Obi..]

At this point I am gonna say a bad master cylinder. One of the seals didn't look good and made the rest of things keep going downhill from there. It was the only thing still there from when I got it aside from the steel lines.

Add in the fact I drive it like it's a sports car and it all added up to this.