Grinding Noise When Slow Breaking.

PCM · September 30, 2015

Dear experts,

Any thoughts would be appreciated...

When breaking at low speed, I can sometimes hear a pulsating, grinding noise, which slows as I slow - when breaking.

About 3 months ago I had a seized rear calliper replaced (under warranty) on one side.

I'm wondering if it might be the case on the other side, or something else?

i'll have to take it into Lexus I think, but am still wondering what it could be.

Has anyone else heard similar grinding (on,off,on,off ... ) type brake related noises?

Regards.

steve2006 · September 30, 2015

Can you feel any pulsing through the brake pedal when it happens?

I assume that non of the pads are down to the metal backing plates?

PCM · September 30, 2015

I can hear it but not feel it...

Bought it from a Lexus dealer 6 months ago.

Serviced and Mot'ed about 6 weeks ago.

So I believe all was fine then...

rayaans · September 30, 2015

I can hear it but not feel it...

Bought it from a Lexus dealer 6 months ago.

Serviced and Mot'ed about 6 weeks ago.

So I believe all was fine then...

Sounds like metal on metal contact so Id assume the pads are down to the metal.

Or - there might be a stone in it

best to get it checked out regardless.

steveledzep · September 30, 2015

I've experienced something similar on a Golf.

Think it was a stone lodged in the brakes as Rayaans has suggested.

Driving forwards was a terrible racket, I reversed and applied the brakes and the stone must have dislodged.

Try it.....you never know ?

ColinBarber · September 30, 2015

Make sure there is no corrosion on the disc surfaces, this happens when your calliper is seized which results in part of the disc never coming into contact with the pad to keep it clean and rust free. This typically results in a grinding noise. To resolve you would need the disc surface to be skimmed or the disc replaced.

The following is an example, the inside half of the disc is corroded and will result in a grinding noise when you apply the brakes and the pad comes into contact with that non-smooth surface. The lip on the outer edge isn't a problem.

ChrisKaye · September 30, 2015

When I change discs on my cars, I have been spraying the hat and hand painting the lip as it keeps that horrible rust at bay.

If the owner of the car in Colin's pic had caught the above soon enough, he could have refurbed the calliper and wire brushed the disc.

As things stand, he/she's probably had to have new discs & pads and hopefully sorted the calliper!

Quite costly, versus an sunny afternoon's elbow grease...

ChrisKaye · October 1, 2015

Here's a pic of one of my painted discs a year on taken of my MR2, I've not done it on the Lex yet!

PCM · October 3, 2015

Thank you all.

Booked in to Lexus this week.

Will let you know how I get on ...

iain57 · October 5, 2015

We have had a similar issue with my wife's RX300. It's the near side rear and only happens with slow braking.

The caliper was stripped down and greased etc. To no avail. Had it checked at a Lexus garage who couldn't find anything wrong.

I opened a similar post some months ago and someone advised adjusting the parking brake so that it, basically, doesn't engage when operated. Had this done in conjunction with replacing the discs and pads and the problem went away, for a while!

Since having the car mot'd the annoying noise is back so I am going to have the parking brake mal adjusted again to see if it goes away. Will let you know the outcome.

ChrisKaye · October 5, 2015

I've had this too on my celica, the parking brake is a drum like on the RX.

Slow speeds such as pulling up to traffic lights, you could hear a rotational "shhh" "shhh" "shhh" noise that slowed when you did and sped up when you pulled away.

When changing the rear pads recently, you could hear/feel the noise while the wheel was jacked up and turning it by hand.

That was also on the nearside as well!

Adjusting it (slacken it off) did make it go away, fiddly but very do-able if you remove the wheel and spin the adjuster with the tip of a screwdriver - the adjuster lives behind a little rubber plug in between a couple of the wheel bolts on the hub.

I wound ours all the way out, then counted the turns of the adjuster until I had it just right, then reset the other side to ensure brake balance remained. This only affects the parking brake and not your rear discs & pads.

PCM · October 5, 2015

Thank you.

These are all 'things' I can mention when I take it in on Wednesday.

:hocus-pokus:

PCM · October 10, 2015

Well...

You were sort of all correct...

It was a combination of a sticking parking brake AND a seized calliper.

( I'd had one rear calliper done about 3 months ago - under warranty ).

So ... because of my [excellent] Lexus Warranty, I had the parking brake freed up, a rear calliper replaced and a car wash and vacuum.

Total cost £0

:hocus-pokus:

ColinBarber · October 10, 2015

Glad it is all sorted out :)

PCM · March 13, 2016

On 10/10/2015 at 11:43 AM, PCM said:

Well...

You were sort of all correct...

It was a combination of a sticking parking brake AND a seized calliper.

( I'd had one rear calliper done about 3 months ago - under warranty ).

So ... because of my [excellent] Lexus Warranty, I had the parking brake freed up, a rear calliper replaced and a car wash and vacuum.

Total cost £0

:hocus-pokus:

And now it's back again... :(

I am surte the brake is sticking, as I hear that 'shhh', 'shhh', sound at low speed.

I've read that salt can cause it, and lubricating a cable can help.

We have certainly had salted roads recently.

Previously, the dealer said to keep using the parking brake, and that would help.

Despite the 2 new rear callipers a while back, it still seems to be an intermittent issue.

Does anyone here have any words of wisdom at all ?

Regards, Piers.

ChrisKaye · March 13, 2016

Hi Piers,

I would really like to hope the new callipers haven't gone bad at only 6 months!

My money is on the parking brake shoes, do you know the last time they were changed, assuming they weren't done when they did your callipers... Like brake pads, they will eventually wear down to the metal, so it could be time for them to be changed.

If they get checked out and are ok, then it is possible it could be that the parking brake cable has started to seize a little, this was a common issue on the MR2's especially in winter as water could make it's way inside the cable and freeze causing to to corrode and the parking brake to not disengage fully.

I mentioned above that I had the same noise on my Celica, and a simple adjustment of the parking brake shoes at each back wheel (spin a cog to slacken it off all the way, then spin in opposite direction to tighten up to just before they bite) - I did this over 8 months ago and still noise free.

Do you have to push the foot park brake almost to the floor before it engages at the moment?

Ta,

Chris.

PCM · March 13, 2016

Thank you, Chris.

Sound thoughts as always.

Yes, the foot brake has a lot of travel!

Piers

PCM · March 14, 2016

Well... I left my foot brake off last night - and the sound has disappeared again.

Guess the break freed itself up overnight?

ChrisKaye · March 15, 2016

Well, sounds like it's definitely the culprit.

It could be the temp variations through the evening -> night -> morning has helped the parts unstick/free up.

At this point it is worth finding out if it's the mechanism (inside rear brake disc hub) or the cable that is jamming. If it's the mechanism, it can be cleaned up with a wire brush and some penetrating fluid, if it's the cable, then although you might be able to temporarily unstick it, you'll have to replace it - once it's gone, it's gone! The cables them selves are usually silly money tho :(

PCM · March 15, 2016

Thank you, Chris!

eric.3d · June 4, 2017

Hi, This happened to me , i was able to solve it. I had a pulsating sound in the rear left side when i break softly. It happened sporadically in corners and on higher speed.

I had the front control arm replaced and it helped by stopping the high speed pulsation , but it continued in the rear back left wheel. even sounded like bad struts when i went over bumps.

i had all 4 rotors and breaks replaced, and problem continued, I replaced 2 rear struts and problem continued, finally double checking the rear tire while the car was elevated I grabbed the tire on the right and left and pushed hard to the right and left of the tire and mechanic could see that it was the suspension rear arm assembly ( control arm ) the bushings where bad and that solved the problem.

PS - my car is a lexus rx 300 2003 FWD, and autopart part did not work because they all where 4WD 1/2 inch larger - so i had to buy part from Lexus, or get part number and buy from eBay.

see attached pictures