Scraping Noise with Rear Brake Drums

Hello All,

I have been lurking for awhile but decided that now would be a good time to make my first post. Still working on getting my member details filled out.

My truck is a 2002 4x4 Extended Cab V6 with Manual Transmission. Mileage is approximately 216,000. I have owned the truck for about a year.

So I recently had both rear axle bearings replaced due to a howling noise in the rear of the pickup that would start at around 40 MPH. I picked the truck up from my mechanic, took it for a test drive and everything was nice and quite. I noticed that the brakes weren't quite the same as I was used to. The brakes seemed a bit spongy and had to push harder on them in order to stop. I called my mechanic and he said that there was a feature where if you went in reverse and applied the brakes, then the brakes would self adjust. I did this 10-15 times sometimes using the pedal and sometimes using the E-Brake. This seemed to help some so I figured I would drive it a few days to see how they performed. After about the second day I had the window down and noticed a scraping noise that sounded like it was coming from the left side rear brakes. It wasn't constant it was more of a pulsing rotational noise. I am taking it back to my mechanic tomorrow but out of curiosity I decided to have a look on my own. After taking the drum off I discovered shiny metal where the drum was rubbing on the backing plate (I think that's what it's called). The inside of the drum is shiny where the two line up so I am pretty sure that is the noise I am hearing. Does anyone know what could cause this? It wasn't making this sound prior to the install of the new axle bearings. Here is a photo.



My mechanic had mentioned that he had a hard time removing the drum because the brakes were adjusted so tight. I also noticed that the drum was chipped (it appeared to be new since the metal was shiny where the chip is). Other than not being able to run a screw in on this side to assist with removing the drum, Is this a safety hazard?

Thanks in advance for your input.

 

IMO drums aren’t that expensive if you get some decent duralast ones. I would replace them even at your mileage. Good luck.

 

Thanks for the feedback knayrb. I don't have any problems getting some new drums for peace of mind but would like to take care of the scraping noise first. I am assuming that the drums aren't the cause of the scraping noise.

 

It appears he bent your backing plate while removing the drum.

 

Yeah Brokebrute. That's the only thing that makes any sense. I'll see what he has to say once he has a look at it.

 

The drums are a pain in the ass to take off if they have been on for too long. releasing the parking brake should be enough to get them off BUT not if they've been on there long enough to cause a lip on the inside of the drum which would catch the shoes. My first set I had to literally use a 4LB sledge to get off. The broken piece you see is him trying to use 2 bolts to pull the drum off (that's literally what that area is designed for). Obviously he was trying to do the right thing with the right procedure but was not doing it carefully. I have cracked that area on my drums trying to pull them off and that didn't cause any issues.

I personally don't think that that broken piece will cause any problems. However; just for peace of mind I would just replace the drums if you are in a position to do so. That broken piece isn't structural as the drum is smashed in between the rim and the hub so you should be fine. Also, that piece is so little that it wouldn't cause any balancing issues.

The bent heat shield in the back was done by him as well. I know this because I almost did the same thing on mine. When I was unable to get the drums off using the 2 bolts (I notices the drum start to bow/crack where the broken piece on your drum is) I backed the bolts back out to prevent the breakage you see on yours and used my sledge as I stated before. It is very easy to miss the drum as you are hitting it in a 45 degree angle since you cant hit it from the back and accidentally hit the heat shield. I wouldn't beat up your mechanic too much honestly, although he was a bit too rough on everything.

Just get 2 new drums for peace of mind if you want (it's not much of a safety hazard if it was worse or more areas broken I would say replace) and use a pair of channel locks to bend the heat shield back in a way so it does not rub or interfere.

 

Thanks for the reply Russianman92. Just to be clear, I believe the drum is scraping on the inner ring of the backing plate (or is this the heat shield you are referring to?). There is a shiny arc about 90 degrees that seems to be touching the drum. There are also a few bent spots along the out surface of the backing plate. Correct me if i'm wrong but I think the outer surface is what you are referring to. If a bent backing plate is the issue, it seems like the left side of the plate (as pictured) would need to be bent back in order to clear the drum.

 

If you can't wrestle the drums off manually, they should pop right off using the bolt method. If not, crawl under the truck and loosen the star adjusters. I'm surprised your mechanic took the brute force approach...

Here's Timmy with another helpful video - https://www.youtube.com/watch?v=vPiJHIMWvIA

It's helpful to see the adjustment with the drum off as Timmy shows, but in 'your' case you'll come through the rear access port. It is tedious.

 

Right, The drum rides in between the inner and outer ring of that heat shield (I guess what I should have said is dust cover). Regardless, if you hit the outer portion of that dust cover with a hammer it will bend the whole thing forward (towards the outside of the vehicle) and make the inner and/or outer ring contact the drum. The dust cover is essentially a backing plate to hold components such as the shoe springs together and to keep stuff out of the brakes.

So, YES. Just bend the thing back in to place and you're good to go

 

@whitetaco2002
Sorry to hear about your experience.

I would find a different mechanic.

One who has two brain cells to rub together.

 

I was able to get the drum off myself, probably because my mechanic had already done this a few days ago and loosened the brake adjustment. Thanks for the video. I am sure it will come in handy.

 

I understand now. I probably should have done this myself instead of taking it back to my mechanic. Only problem was I only had access to the bottle jack so I couldn't really test it before putting everything back together since the other wheel was on the ground. I plan on getting a floor jack, jack stands, etc. so that in the future I have more control over everything by doing it myself. Which is a major reason for joining the forum.

 

So I picked up my truck from the shop today. He said that he used a flat bar to bend the backing plate back in line. Everything sounded nice and quite until I turned into my neighborhood. So now it seems that there are no scraping noises except occasionally while turning...Grrrr. I guess I will be taking a look at it again this weekend.

 

Exactly. Amen. Been there - did that - about 25 years back. (Sure made a noxious sound when driving!)

 

And for those that live in the salt belt. A little PBlaster goes a long way to freeing up the drum from the hub.

Don't saturate but get at least a little there to soak in around the hub area. this is the main problem due to collecting some brake dust and nominal rust build-up.

most of the time the two bolts won't do anything until that drum is loose. even then the drum will take a little wiggle to get off due to the build-up on the inner edge

I also wire brush and use a little grease when putting the drum back on for future maintenance.

 

Been a bit busy lately but have since picked up a floor jack a few jack stands. Currently, I only hear the scraping noise when making right turns. The noise goes away while braking during the turn. I tried a couple of times to bend the backing plate back in towards the middle of the truck but this thing is pretty stiff. I think I am mainly just bending the outer rim but the inner rim doesn't really seem to budge and it's the part that is scraping on my drum. I have tried to use various clamps between the outer part of the backing plate and anything I can grab towards the inner part of the truck but don't really seem to have the right tools. Even tried placing the end of a 2x4 against the outer rim and whacking the other end with a hammer (maybe need a bigger hammer). Apparently I am not putting enough force on it as I don't want to make things worse. I even thought about using a scissor jack against my garage wall with a 4x4 in between the jack and the backing plate (I must be getting desperate) but wouldn't want to push my truck off of the jack stands . I doubt that would really happen but not sure if I want to chance it. I 'd like to resolve this without going back to my mechanic if possible.

 

Sorry I did not see this reply. You should not have to put THAT much force to bend it. If it isn't going anymore, then that's all you can do there. Can you visually see any shiny metal of where it may be scraping?

 

Is the backing plate bolted onto something? What I'm getting at is can it be loosened and adjusted a little before retightening?

And the mechanic was wrong about the drum brakes self-adjusting when going backwards and applying the brakes. On Toyotas they self-adjust whenever the parking brake is applied. When new shoes are installed or whenever the star wheel is screwed back in you can repeatedly apply the parking brake to have the shoes self-adjust. Do this with the drums installed on both sides!

 

Yes, I circled the shiny metal in the picture in post #1. I finally got tired of messing with it and took it back to my mechanic. It turns out he was on vacation so the owner of the shop looked at it. He filed some metal around one of the inside edges of the backing plate. Not really doing anything to address the issue. One of the guys drove it and said that they couldn't hear any noise. The shop owner tried to say that since the truck had over 200,000 miles, the parts just don't fit together like they used to. I called BS on that and decided not to waist any more time trying to argue with him. Long story short, I was able to duplicate the problem within 5 minutes of driving it away. I decided that I wasn't going to waist any more time with this shop. I made an appointment with the Toyota dealer but then decided to take one more look at it. I ended up positioning the end of a 4x4 against the spot that was scraping and whacking it with the flat end of an axe. It really didn't feel like it budged any but after taking some measurements, it did move a little bit. I put everything back together and no more scraping noise. And yes, it is a very ridged piece that doesn't bend very easily. I figured they had a 20 ton press to get the old bearing off and somewhere in the process they bent the backing plate so that the plane of it wasn't at a 90 degree angle with the axle (if that makes sense). I kept the appointment with Toyota to have them look at a vibration. They said that I had two out of round tires in the rear that couldn't be completely balanced (using a road force balance machine). I had purchased a set of Hancooks about a year ago from the same shop who did the axle bearings. Sorry for the long post. I just wanted to update with the latest.

 

I think you have to take the axle out and then unbolt the backing plate. I would think if you tried to adjust it with everything apart you wouldn't know if you made any difference until you put it all back together and test drove it. If no success then you would have to do it all over again.