Squeak at low speed

[Spackers]

I’ve a 991.2 S and it’s developed a squeak in the rear wheels at low speed in time with the revolution of the wheels.

The OPC has checked it and can’t find anything. They’ve told me to brake hard.

Have tried this a few times. Have also driven 600 miles since the OPC check and it’s still there. Any ideas?

 

[Lancerlot]

If you have PCCB's and these are prone to squeals and squeaks, particularly in hot, dry, dusty conditions. Sometimes they're fine, then exceptionally noisy at others. Try a few very hard applications of the brakes from very high speed to clean them up. Get them stinking hot if you can.

If this doesn't work, you could try removing the pads, using a high pressure airline to blow the dust from all components and refit using a very light application of non-metallic anti-squeal grease on shims and pad backs.

Whatever you do, the noises may return periodically - it's just one of the prices you pay for having the uprated system.
Regards,

Clive

 

[Spackers]

Hi Clive, Thanks for this, I don't have the PCCBs and have tried very hard braking, but it's made no difference and the OPC has cleaned them out. Very strange! It does it all the time now when I'm driving at low speeds - 5-20mph. Very annoying sound with the sunroof open! At least they've had a good look so if anything major goes wrong it should be covered under the warranty.

Thanks, Kind Regards, Chris

If you have PCCB's and these are prone to squeals and squeaks, particularly in hot, dry, dusty conditions. Sometimes they're fine, then exceptionally noisy at others. Try a few very hard applications of the brakes from very high speed to clean them up. Get them stinking hot if you can.

If this doesn't work, you could try removing the pads, using a high pressure airline to blow the dust from all components and refit using a very light application of non-metallic anti-squeal grease on shims and pad backs.

Whatever you do, the noises may return periodically - it's just one of the prices you pay for having the uprated system.
Regards,

Clive

 

[Lancerlot]

It's good news you are on steel rotors since this makes it much easier (and cheaper) to resolve. It's just a case of how much you're prepared to do or spend to sort it out.

Take a look at these 2 videos as I think it may help you understand the problem:-
https://www.youtube.com/watch?time_continue=4&v=fUNHb9O52WQ
https://www.youtube.com/watch?v=ivMB4WEGgZo

If it were me, I would firstly check the rotors for surface defects and run-out problems and if OK, try fitting new, genuine Porsche pads.

If the problem persists then it's possible the rotors have become contaminated and will need to be replaced (again use genuine Porsche parts). After this, you would need to be looking at more complicated engineering solutions such as defective callipers, mountings, hubs, wheel bearings etc.

However, new pads and rotors should usually resolve the issue.
Regards,

Clive

 

[Spackers]

Hi Clive, thanks ever so much for your helpful advice. I'll give it a try. My biggest concern was that it is the bearings; although shouldn't be this on a three yr old car with 14k miles!

 

[Lancerlot]

You should be fine on wheel bearings since the noise is only evident at low speed. If it disappears with a light application of the foot pedal, it is definitely brake related. I assume you've already checked that the handbrake is not binding and there's no gravel lodged anywhere in the calliper, rotor or dust guard?.
Regards,
Clive

 

[Justanothercarguy]

I’ve a 991.2 S and it’s developed a squeak in the rear wheels at low speed in time with the revolution of the wheels.

The OPC has checked it and can’t find anything. They’ve told me to brake hard.

Have tried this a few times. Have also driven 600 miles since the OPC check and it’s still there. Any ideas?

Hi there. Sorry to dig up an old thread, but I have this exact same problem in my 991.2 and I wondered if the OP had resolved the problem?

In my case, the squeak happens at very low speeds (>10mph) and appears to come from the rear right wheel. I've had the car since new and it's only done 12k miles. It doesn't happen when I brake, just when I'm driving slowly.

 

[Scrounger]

Try cleaning out the brake disc and caliper with brake cleaner. Worked for me on my 718 GTS with a squeaky rear brake.

 

[Duncs04]

Hi there. Sorry to dig up an old thread, but I have this exact same problem in my 991.2 and I wondered if the OP had resolved the problem?

In my case, the squeak happens at very low speeds (>10mph) and appears to come from the rear right wheel. I've had the car since new and it's only done 12k miles. It doesn't happen when I brake, just when I'm driving slowly.

Ive had a similar issue on my 991.2 for at least the last 12 months and the noise is coming from the right rear and is in time with the revolution of wheels at very low speed.
It only happens just after i have lifted off the brake pedal and the car is moving at low speed.
It’s been with the OPC numerous times and ive had the rear discs and pads changed and all the brakes components stripped and cleaned twice. The noise returns and is intermittent. Its annoying but Ive done 8000 miles with it and the OPC has checked it out and could not find an issue so I just live with it now.
I now suspect that it might be the hand brake shoes catching and will get them replaced at its next service as a matter of course, just to tick it off.

There is a 2018 991.2 GTS in my village and i noticed that it makes the exact same noise at low speed, which made me feel better.

 

[Justanothercarguy]

Thank you for the replies. Interesting to hear it's not just me! I drove it to France over the summer, so put about 1,000 miles on it, and the squeak is still there. Perhaps not as noticeable as it has been, and maybe also more intermittent, but still there.

 

[Motorhead]

Tracing brake squeak/squeal is always tricky, and a bit hit-and-miss. Assuming there’s no disc run-out, other than replacing all the brake components the best you can do is ensure that everything is clean, and it’s worthwhile running a drill through the cross-drilled holes to ensure that they’re all clear.

Smearing a very thin layer of high temperature grease [Optimoly TA?] on the edges of the pad backing plate may help, as could replacing the pad dampers located between the pad and piston. These lock into a hole in each piston and are secured to the pad backing plate with sticky tape.

The handbrake is separate from the disc brake, with brake shoes operating on the internal surface of the disc bell. You could try backing-off the shoes temporarily on the offending brake to see if that stops the squeak.

Jeff