Howling sound when turning right / reversing (Mk2 Focus)

shietpilot

Hi all,

My Focus has developed a howl when turning right around roundabouts or reversing.

Initially it started out as a howling noise when I was reversing and braking at the same time. This is with brand new OEM discs/pads all around.

Now the howling has gone worse and it occasionally happens when reversing or turning right. It only seems to happen when the car has been driven for a bit.

It sounds exactly like in this video:

Generally reversing with the steering wheel turned to the right causes it, without touching the brake pedal.

I removed the brake pads all around twice and re-greased everything and made sure the sliding pins are well lubricated and move easily. Could it be the front left wheel bearing causing this kind of noise?

I'm kind of desperate for a fix so I've actually loosened the handbrake a bit at the lever to make sure it's not catching and forcing the rear brakes on.

The car has disc brakes all around.

Hal1

That sounds like a brake pad in contact with a brake disc. If so there may be a high spot on one of the discs, or a piston isn't releasing fully on one of the calipers. Check for excessive heat after driving around for a while, but try not to injure yourself.

shietpilot

Hal1 wrote: »

That sounds like a brake pad in contact with a brake disc. If so there may be a high spot on one of the discs, or a piston isn't releasing fully on one of the calipers. Check for excessive heat after driving around for a while, but try not to injure yourself.

No excessive heat and no spots on the pads/discs, everything looks mint which keeps making me think it's not the brakes

Hal1

Any noise from the power steering pump and is there fluid in it? The hose that feeds the pump is known to split and when it gets low enough it gets noisey.

FortySeven

Hal1 wrote: »

Any noise from the power steering pump and is there fluid in it? The hose that feeds the pump is known to split and when it gets low enough it gets noisey.

They also leak from the pressure switch in the pump. Very common.

shietpilot

Hal1 wrote: »

Any noise from the power steering pump and is there fluid in it? The hose that feeds the pump is known to split and when it gets low enough it gets noisey.

Electric power steering is fine too and sounds good. It's weird because when you get the howling noise the vibration is sent through the body, I'm still wondering if it's possible to be caused by a wheel bearing

FortySeven

shietpilot wrote: »

Electric power steering is fine too and sounds good. It's weird because when you get the howling noise the vibration is sent through the body, I'm still wondering if it's possible to be caused by a wheel bearing

Very likely. You seem to have ruled out the other possibilities.

shietpilot

Well it's definitely the rear brakes. The noise happened today whilst going around a roundabout and I lifted the handbrake up one notch and the noise stopped. Putting the handbrake off again made the noise to reappear.

biko

Time to disassemble the calipers and clean I suppose.
Slap some copper grease on the back of the pads too.

shietpilot

biko wrote: »

Time to disassemble the calipers and clean I suppose.
Slap some copper grease on the back of the pads too.

Plenty of grease on them. I looked at the rear brakes again yesterday and I honestly don't see any point in pulling the calliper apart. The brake pads are wearing very evenly and the brake disc looks very good. There is no excess heat in any of the wheels after a long drive.

When I turned one of the rear wheel yesterday I heard the wheel bearing make a quiet TICK-TICK-TICK sound as I was turning the wheel. I'm wondering if maybe the noise is caused the wheel not turning in a straight line when I'm reversing into parking spots and causing excess force on the wheel bearing but I'm not sure if applying the handbrake would fix such an issue

blackbox

I'ts unusual for a wheel bearing to make a howling noise at low speed - e.g. reversing.

Do you think it could be a bearing in the transmission/differential?

.

shietpilot

blackbox wrote: »

I'ts unusual for a wheel bearing to make a howling noise at low speed - e.g. reversing.

Do you think it could be a bearing in the transmission/differential?

.

Definitely not the gearbox anyway. The sound are coming from rear wheels but that one dodgy wheel bearing has me thinking...

shietpilot

Spent most of the day messing about with the brakes and I've somewhat fixed the problem.

The howling noise when turning right was caused by the rear nearside (left) brake. There was a shiny spot on the carrier for the inner brake pad so I removed the carrier and tried to slide the brake pad on the surface where the pad sits. It was getting caught on this shiny spot so I thought maybe the brake pad was lightly rubbing against the disc when it was stuck in this groove (because applying the handbrake removed the noise). I filed the surfaces on the carrier down and greased the same areas on the brake pads. Put it back together and hey presto, no more noise turning right.

The noise from the front pads still exists when reversing and braking but it happens rarely. I suspect it's because the pads are always used when moving forwards and they must be catching somehow when reversing.

Hal1

Glad you got it sorted. Maybe it's the same scenario on the fronts? Clean up the rust and a bit of silicone grease on the slider pins, copper on the back of the pads and contact areas. I use a wheel attachment and a hand file too, it takes a few minutes extra but worth it if there's no brake squeel.

shietpilot

Hal1 wrote: »

Glad you got it sorted. Maybe it's the same scenario on the fronts? Clean up the rust and a bit of silicone grease on the slider pins, copper on the back of the pads and contact areas. I use a wheel attachment and a hand file too, it takes a few minutes extra but worth it if there's no brake squeel.

I had already sorted the sliding pins and they move really well since the last time but they weren't the cause.

I will probably take the fronts apart, remove the carriers and clean them up too. The inner side was probably the cause because it's hard to see with the brake disc in the way :rolleyes: