Rear brakes pulsating after replacement

Hello everyone,

I have owned this 2000 prerunner for almost three years. I don’t drive it all that much. But noticed some braking shaking which I didn’t like.

So I did the front brakes last week. Using Stop-Tech slotted rotors and Toyota pads. After bed in the brakes stopped amazingly.
So decided to check the rears and they were pretty worn as well.
Put new drums and Toyota shoes, changed all the springs and hardware.
Bled the entire system.
But now I’m noticing even more shaking under braking. I know it’s the rears because if I pull the E brake it does the same pulsating.
But like I said I bought all new brakes so there is no warping or anything like that to be in question.
So my question is, could it be the wheel bearings?
Thanks in advance for any guidance.

And I do not have a press so if it is the wheel bearings I would have to take it to a machine shop to have the bearings removed and new ones pressed in.

 

Did you check your drums to ensure that they're actually round?

 

No I did not but they are brand spanking new.
I have never had to before and never had an issue.

 

Drums don't usually have issues, but I'd throw a dial indicator on it just to double check.

 

Stores have been known to store brake Drums in a up right condition to save space .

They will indeed warp like that they should be stored flat

since you now have a problem you did not before

 

Lots of brand new brake drum horror stories on TW.
Pull and have them turned at brake shop.

 

Yep, it's not too out of the ordinary to have to turn new drums espescially if in the lower price range.

 

Thanks guys I totally did not expect to hear this. I bought Centric drums so not some cheap brand. But who knows these days.

Personally never ran into this issue.

I guess I will pull them and take them to a machine shop for inspection and/or turning.

I will update this post after I do that.

I am going to check the wheel bearings as well. I’m pretty sure they are original and at over 250K they could be pretty worn as well.

 

So this morning on the way to work around 5:00am I message my wife and ask her to go out to the trash that was out for pickup today and remove the old drums from the trash. I know right. But she is a sweetheart and went and did it.

So when I got home I removed the new drums and put on the old ones. They were still within spec. Adjusted the brakes a little then went for a ride.

No more pulsating!!!!! I can’t believe it; the new drums are out of round just like some of you said could be the issue.

I am absolutely beside myself and quite upset about the whole situation.

But I am thankful for all of you and your support, and that I got rid of that terrible pulsating.

All good braking now

Thank you TW

 

Glad you got it working!!

I have so many uses for old brake drums I never toss them in the scrap.

Many brake pulsing issues get blamed on the front when both axles are done seldom are the new drums thought of a possible source of the problem.

Then all kind of new parts are thrown at the front brakes and the issue is not corrected.

 

Thanks W09,

Yeah this is the first time I have ever bought new brakes of any kind drums or rotors and had issues with them out of the box.

A member here mentioned that they could have stored them upright instead of flat which could have caused the issue.

I wouldn’t think that steel that tick could become out of round but maybe it can be.

Or maybe someone bought defective Centric rotors and tried selling them as new, who knows.

But I am sure happy that issue is gone.

 

Congrats @Knifenut , we learn something new every day

@Wyoming09 , would you mind listing some of your alt uses of brake drums? Curious for sure. TIA

 

I tend to use them a lot as bases for all kinds of things light stands

supports for the long lengths of steel for the band saw

a few other things I just can`t t recall right now

 

So appreciative of this information. Much like what happened here. I did my front pads and rotors and thought I better look into the rears. They were in desperate need of replacement. New shoes, drums, springs and even adjusters for my 2000 prerunner. Finished at midnight, went for a test drive and it was horrible. Thought it was due to not cleaning the drums first so I took it all apart, sanded lightly both drums and shoes (shoes had what I can only call ‘chatter lines’) put it back together and the same thing happened. Thought maybe it was my rotors from the pulsing but pulled the emergency brake and I began hopping like a bunny rabbit. Took it back apart, thought maybe I didn’t adjust them properly, maybe too tight. Cleaned it all again, put on the drums, adjusted them looser, about to mount wheels back up and thought to google, 2000 Tacoma Prerunner V6 new rear brake chatter and this came up. Grabbed my old drums, wire brushed and 400 grit sanded them. Installed and . . . Like butter. Perfect. Yum. And what a waste of time. Took the drums back. They said, “yep, it happens. Geez.

Anyway, thank you all for sharing your knowledge. Much appreciated.

 

incredible
thanks for follow up!!!!

 

And here I am getting ready to do the drums tomorrow. Needed something to help stress me out some more. New NAPA premium line drums too.

 

Yeah, the only drums I’ve ever bought that didn’t suck were OEM. Raybestos was second best, Centric can go eat something. Rock Auto should drop them.

 

Glad I'm reading this. I have new Power Stop rotors and ceramic pads coming today. I don't have any issues other than I'm tired of the old metal & carbon pads spewing dust all over my rims. The old rims were oxidized and the chrome was peeling off. Ceramic is supposed to be much less dust since they actually coat the rotor instead of gouging it. That is what I read anyway. Just bought new black Enkei Rims and BW Toyo Open Country A/T III tires and have more time to wash now.

I have never changed back brakes since I bought it in 2003 new. I figured it is time. 129k miles but I'm reading some people are getting 200k and more out of the OEM back brakes, and now with this thread pulsations after putting on new drums. WOW I think I'll go back to if ain't broke don't fix it. Besides I have always been a very light brake-er...because I watch what is happening on the road a 1/4 mile in front of me.

The caliper and drums are rusty so I was thinking of painting them to make the new rims highlight better while I do the brake jobs and fluid flush - I'll do that with the old pads and shoes on then swap out the rotor and new pads, I'll leave the shoes alone for now. Check for any weird pulsations after pads and rotors.

There is a great article in a brake thread on here about runout problems being caused from turning your rotors and drums and the hubs not being cleaned up prior to new installation. Further compounded by the auto shops not calibrating their machinery properly. In that thread it is stated that in general new rotors tend to be more accurate and true before turning them especially if you remove rust from the hub surface. Similarly the rim surface to the rotor and drums can exacerbate an alignment and or a pulsation.

 

As I stated I just put on new rims and tires. It never occurred to me that the minor vibration I was getting prior to new rims and tires was the old rims and tires. I was ready to be replacing my drive shaft in the near future or at least the center bearing. I hadn't noticed until last night that the vibrations were gone completely. So I lived with an unbalanced wheel for about 12 years!!! Never got worse or better until new wheels and tires, mounted and balanced. Alignment still perfect, no pull to either side, drives dead center in the lane for three blocks or until there is a clear dip or uneven road. No pull when braking.

That is called added value. I'm happy anyway.

 

FSM has a spec for the ID of the rear drums, and likely it is stamped on the drum too (IIRC standard: 295.0 mm and maximum: 297.0 mm for mine). So can measure them to determine if they can be reused or turned if necessary, instead of just throwing them out and replacing. Like PO discovered they may be superior and still function, even better perhaps compared to something purchased new aftermarket.