Installed new rotors, rebuilt calipers, and semi-matalic pads. Now I'm hearing a loud creaking noise from just the rear (hard to tell sometimes) when stopping and starting. No squeal while stopping, just when coming to a stop and then again when lifting off the brakes to start.

I bought some disc brake lube and coated the backs of the pads and the metal edges. No change. I do not have shims and the rear caliper piston tops do not have a notch.

Thanks everyone for your help. The brake noise issue is not completely solved yet but the noise is still greatly reduce after the single WD40 application. Its now more of a chirp than a screech.

There has been a single squeaky rubber bushing that I can reproduce by bouncing the car’s rear. Its, to me, a definite rubber sound as opposed to the metal-to-metal screech. The shocks are totally quite. Just for my own info I will try WD40 on one bushing at a time to identify it when I get back under the car again.

I do plan to sand and clean the rotors (and pads as well) with an actual brake cleaner. It does seem like a possible contamination problem given the WD40 effect. I’m also going to clean the caliper mounting surface and bolts. The caliper pistons moved smoothly when I removed the pads to apply disc brake lubricant to their backs and metal edges. This had no effect.

First the original calipers did have notched pistons. I sometimes set them but it never seemed to matter. I forgot about ordering shims so that's one thing I will try. So far I've only driven a few times around town so I'll get out on a highway with some curves to try to bed in the pads.

My first guess had been the noise was the pads moving around in the calipers so I did apply disc lube to pad backs and edges but it made zero difference. Just to see if the problem was between pads and discs I sprayed some WD-40 (only thing I had on hand) on just the outer disc surfaces of the rear brakes. WoW! the noises immediately and completely disappeared. After a few drives around town the noises have returned but only a little.

Did you try lightly sanding the rotors and using Brakekleen?
--
Will I buy another Volvo??? We'll see....

Hi,

I was thinking the same things that you are talking about doing to the rotors, cleaning them.
In most case when you just change the pads, you can get into cross contamination from older pads to newer pads as formulations change, even within the same manufacturer as years pass.

What stopped me from going where you went was the point that he said that the pads and rotors were new. His calipers came without notched pistons, of which, until Art posted his idea I had no reasoning for its use either.
I tried to put forth an idea, in my other post, as that’s what I do to keep an open mind for others to play with. (:-)
Sort of like a musician’s jam session of finding out what sounds good within those that have discoverable talents and plus of course what might sell in markets.
I have been in on a few those department to department meetings and there is a slang name for it but cannot think of it right now.
Old age within retirement makes the worn cogs rattle more slowly now.

I assume that he did total refurbishment all the way around the car, but it’s not exactly stated as such.

So, like Amarin suggested, it could be the pads have not bedded themselves in. When pads are first put on they have to level themselves in. Level is not a proper term but bedding or the way you lie “in” one is suggesting the same thing as the pads are not comfortable seems to be a consensus.

With used parts, say the rotors not changed in most cases, this is where cross contamination can play a role. The two slightly different compounds will meld and tend to create a glaze either on the pads themselves or on the rotors. On either one, a scuffing action is diminished.
The bedding will take longer or may never.
The idea of using WD-40 is not exactly something I would put on most things but many people have an attraction to that stuff.
It is more of a convenient spray solvent more than anything else.
I have related it to a non-oily, low sulphur diesel fuel with a fragrance added.
It removes gummy stuff!

I would suggest what you are suggesting plus taking the new pads a scuff the wear surfaces on top of a clean sheet of reasonably coarse sandpaper for wood, garnet or even aluminum oxide, laid down on a flat surface. An open grit will allow material to scrub off.
About a dozen shifts or on the paper should bring up new material evenly.

Sanding the new rotors isn’t needed but can get a microscopic sheen quickly depending on its heat treatment processes.
During machining, coolants are used that have evolved to reduce environmental impacts and these Cleaners usually take care of it.

On “Used rotors,” different story. They will definitely need a light spiral scuffing as we don’t know what the car puddles of dirt and road oils it has been driven through.
I use a angle sander with a flap pad wheel and just lightly put a clean scuff across it while spinning it by hand.
I also bevel away any outer or inner ridges that might stand up against a new replacement set of pads.
They can prolong the bedding process.
I have read that it can take up to fifty miles of average driving.
I don’t know how scientific that statement was?
Nor about holes and slotted rotors and removing pad gassing for the average driver either?
I’m average but not for gimmicks. (:)

On new rotors, they should be cleaned with a brake cleaner to remove any coolant preservative that keeps them shiny in a box for the customers.
Even coated wax or oiled paper can contaminate the metal and you want it clear of that.
Cast iron is somewhat porous but you don’t what it to be a seasoned frying pan! (:-)

I hope from all our posts about this subject will give everyone a smooth brakes.
You want to see them work and not hear them complain about it.

Phil

Brakekleen! Totally forgot about that product. I was just thinking of how to do a test that would tell where the problem was. What should I use to sand the rotors, fine emery cloth?

Hello,

Several tips here. Let the brake parts settle in (bed-in) for first few weeks by keep using the car. Another tip is to use brake parts cleaner (spray) to all exposed parts. Sometimes a small dirt lodged could make such noise in which situation a through cleaning is beneficial. Forget about the piston notch, if your brakes don't have it then its non-issue. Another tip is (when noise still there despite the effort) you might have to replace the new pads with another set of pads (preferably higher quality or OE) in case your current pads material and rotor don't match.

Amarin

"Forget about the piston notch, if your brakes don't have it then its non-issue."

The piston notch is a 240 thing. 7/9 cars don't have them. The reman boys are cheating.
--
Art Benstein near Baltimore

"Most people work hard enough not to get fired and get paid just enough not to quit." -- George Carlin

Creaking from the rear (as opposed to squealing) just as the rear end comes to a rest at a stop and again as you start off would likely be suspension bushings or shocks, IMO. Now if it was coming from the front I'd also suggest the sway bar front chassis bushings which I've found can creak when they get a bit worn and dry (try grease there, best to open them up to do a proper cleaning and greasing). Let me guess if you go slow over a speed bump you get the same thing -you'll then know for sure which end. If it's not obvious when jacked up, you could try soaking areas one at a time with something like WD-40, probably even soapy water, to see if the creak temporarily goes away.

Your rear brakes normally have shims to help prevent squealing, sometimes even two if it's really bad. Some pads have integral shims. Use high temp brake grease on shims, with a good ring of gease at the piston contact area. There are anti-squeal compounds sold that are almost like an epoxy, but I prefer not to have anything mushy there lest it contribute to soft braking. Caliper pistons that are starting to freeze from worn seals or damaged dust covers are a major cause of noise and eventually brake drag.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

"I do not have shims and the rear caliper piston tops do not have a notch."

I believe your Alfred Tevis brakes originally were equipped with the notch and shims specifically for noise reduction. I remember clocking that notch on our first Volvo, an '83, to stop it from sounding like a school bus.




--
Art Benstein near Baltimore

"Why is a birthday cake the only food you can blow on and spit on and everybody rushes to get a piece?" -Bobby Kelton

Hi Art,

Oh that’s what ATE stands for.
I never knew that!
I guess the E is for Enterprises?

I have never seen the rear brakes of any 240 without the angled notch or Alfred Tevis E brand.
I was aware of the 20 degrees but hadn’t considered any reasoning for it either.
It must allowed for the pad to be supported enough to make pad vibrations change into a frequency we cannot hear.
You know, like shorting the length of a slapped wooden ruler that’s held over the edge of a desk.
The sound changes as it’s moved back and forth making its sound change.
Someone decided it didn’t a full skirted isolation barrier like a shim.

This has reminded of a long story so I hope this fits into this thread.
It’s about on a day when I was returning home from my honeymoon up in Spokane Washington. The Worlds Fair of 1974.
You wouldn’t believe how Delco sized and graded the round balls for flaws that went into their ball bearings.
Hint, It reminded be of an arcade skill ball machine with a modified backboard and they just bounced off a steel plate from one specific height.

Anyway, I was looking for shop in the Santa Barbara region that made a special bearing for the big end of a connecting for my 1971 Harley Davidson Sportster.
I was a silly young man, still in the Navy you know, trying to make a Harley better. I figured out that giving one of them a good washing can improve it. (:) Another side story.

Instead I found a guy trying to record the vibrations off different Harley Davidson Models.
His contract was to recommend methods to reduce vibrations from the rider.
Coincidence it was for sure?
We got around to what I was there for and he told me that he was a little familiar with that bearing product.
But this fellow was in renting a suite a few doors down, about a year ago.
Trouble was he went out of business or moved and he didn’t know anything else about the business.
Hmm, Ok?

As we talked more, I began to realize that I stumbled onto, a very small, research business or laboratory for hire.

He actually had one Italian made Harley Sprint that I use to own in my slightly younger youth of 16 years onwards.
I told him what RPMs were the worst on both bikes. No need to record shaking images from a reflection in a mirror mounted on the handle bars.
As we talked more and more I did probably too much, now that I’m older and wiser.

He wanted to reduce vibrations from the foot boards and was trying different rubbers.
I suggested round contact points first like balls. Less transference right off.
I then suggested using a liquid center in side them.
He then wanted to talk more to explain my thoughts.
I told him that vibrations do not travel as well through liquids.
I described the rubbery liquid vessel that’s in the very center of a golf ball and gets a continuous rubber band wound around it.
A suggested a pad made of those features would help diminish vibrations to the feet.
I think today’s applications, that a liquid inside, may be referring to hydraulic mounts. Might even be considered to be tunable.

Just after that statement my bride showed up wanting to show me two brother dogs in a shelter that was in the complex and it was closing soon. I had to break away of course. (:(

Within a few years I noticed, on the big Harley dressers, that the foot boards had a rubber layer showing.
I could see some round ridges on the edges of the top and bottom.
I don’t know how they made internally, to be liquid filled, but I have figured out where the idea came from. That 🥼 laboratory under contract.

Today, the whole engine and transmission is mounted on or in rubber in some fashion.
Last time I one running at a light I could see the cylinders wobbling to and fro.
Those are big pistons moving, not just vibrating like the short stroke Honda multi-cylinder bikes did.
Nowadays Harley doesn’t have to check with the Smithsonian in order to make a change, but they tried anyway with Porsche.
I see now, that the infamous V Rods has failed and are half or less priced, used.
Harley sells emotions and ego hardware.
I Still have my original Milwaukee Iron.
I fitted in there somewhere, then.


As far as the dogs went …
The attendant said, “if you really want these dogs you will come back and do the paperwork.”
We ended up coming back to adopt them because they were closing like she said.
We had two dogs ever since. 48 years now! (:-)

Thanks for reading this far Art but it’s very possible that you named that TUNE!
Also thanks to anyone else that needed short stories for the day.

Phil

Hi Phil,

I misspelled his last name. Alfred Teves not Tevis.

Yeah, I've heard some of the reman calipers available today don't bother with the Ate design with the notched pistons. Gotta be only 1 in 100 customers fussy enough to want quiet brakes on a 40-year old car, and good cores are getting scarce.

Just wanted to say I read your post. Keep up the good work Machine Man!
--
Art Benstein near Baltimore

Vacuum Connoisseur:
I am perfectly comfortable with partial vacuums, however, I'm partial to perfect vacuums.

Hi,

From what you are saying, you have put nice new parts on a old car. (:) Did you expect total compatibility? (:). Just kidding of course.

A creaking sound right when the rotors stop is not one, from my experience, to be a brake issue but more likely a suspension noise.
I don’t know you jacked or lifted the car up one corner of the car at a time the rear axle is not independent.
The body’s attachment points are rubber mounted to that axle.
The axle has large TABs or Trailing Arm Bushings. These are know to go bad very slowly by drying out and cracking or splitting. All rubber bushings under there are susceptible to this aging but the TABs are the largest. There are anti torque rods used to stop the rear axle from rotating on take offs and stopping.
All of these will using create a popping or creaking sound when driving into a driveway approaching ramp at an angle.
The body will twist on the ends trailing arms in different directions and that transfers into the big TABs.
Depending on the amount of age in the rubber the noise will get worse.

If these have been replaced and seem to be in good shape you might want to try some rubber compatible oils on them.
Silicone’s have a nice quality to them but you have to watch out for what type of carrier fluid they use to get the silicone into the joints.

Back in the days of these cars when you could walk under your car with them while it got it’s servicing. They could name off or show you more than 25 service points to impress you.
Yes, he said oiling those bushings. Today they might say a “preservative.”
Like lubricating the cars door hinges and check the tightness of attachment bolts along the rear axle.
Yep, I was young @ about 26 years old.
This was all a selling point, under the up and coming Volvos 36,000 mile routine maintenance warranty program.
In 1986 it went to a transferable “bumper to bumper” warranty. That’s another story or questionable lie.



I did one service in 1980 @ 30,000 on my 1978 GT for about $300.
Not a cheap service but it included checking the timing belt. I didn’t know it meant only adjusting it.
The catch was “Some” Belt replacements were an extra if the mechanic recommends them too.
I don’t remember anything but the $300.

A few weeks later just before a big trip I had planned to Colorado, the air conditioning belt broke. You know that knocks out the power steering.
The dealer was 40 miles away so I tore into it.
This was when I found out about a shimmed split crankshaft pulley that IT DID NOT HAVE on the engine.
No other adjustment. The belt was absolutely muscled on there by rolling it over the edges. When I don’t know.
I also found out that the air conditioning was a new option put on by “ a retrofitter” here in the states after the importation. …??? The information was from this dealer???
I had to drive there, in another vehicle and they gave me the split pulley setup to put on.
The kicker, It was in stock too!
The car has never seen another dealerships bay! Almost 45 years later @ about 350k but it hinges don’t squeak. I’m Not saying anything about all of mine. (:-)

So with that, you need to inspect all the bushings and consider your options of it being a rear suspension noise.
It may settle in and go away or you will learn to ignored it with the radio up a little louder.
(:)

Phil