Technical Strange noise when reversing

[Derek1875]

Hi folks
Hoping someone can get me an idea of what might be wrong....

I have a 2008 Bravo 1.4 active and it's started making a high pitched screeching noise when i put full lock on when reversing it doesn't do it going forward only in reverse and only on full lock any help would be appreciated

Thanks in advance

 

[portland_bill]

Has it got hydraulic power steering or electric?

Hydraulic:
Hydraulic steering uses full pressure on full lock, and a hiss or squeal is normal as the pressure relief valve releases.
The pump is driven by the auxiliary (alternator) belt. If this is not tight enough, or well worn, the pump demand can make this slip. Especially full lock on a cold engine, with cold steering oil.

Electric:
Any noise from the motor will be inside the car, under the speedo.
Similar to hydraulic, full lock demands the most power, provided by the alternator. If the belt is slack or worn, it will slip, squealing as it does so.

Or is the squeal at a wheel?
Front wheel, check pads, or sticking calipers.
Rear wheel, handbrake sticky causing shoes to rub.

 

[varesecrazy]

Has it got hydraulic power steering or electric?

Hydraulic:
Hydraulic steering uses full pressure on full lock, and a hiss or squeal is normal as the pressure relief valve releases.
The pump is driven by the auxiliary (alternator) belt. If this is not tight enough, or well worn, the pump demand can make this slip. Especially full lock on a cold engine, with cold steering oil.

Electric:
Any noise from the motor will be inside the car, under the speedo.
Similar to hydraulic, full lock demands the most power, provided by the alternator. If the belt is slack or worn, it will slip, squealing as it does so.

Or is the squeal at a wheel?
Front wheel, check pads, or sticking calipers.
Rear wheel, handbrake sticky causing shoes to rub.

all good pointers..
still not quite sure why it's "reverse only" though

possibly steering geometry :idea: I know toe-in is fractional.. but may just be the marginal loss - between efficiency and not..

charlie

 

[portland_bill]

Reversing is usually at a slower speed, so engine turning slower, less power to drive belts, so more likely to slip.
Is this every reverse, or just out of drive in morning, with cold engine and cold steering oil if hydraulic, or large load on alternator having just started. Another good reason to reverse into drive.

On full lock, front wheels are rarely accurately pointing, so one will slip. This is what causes the squeal in concrete car parks. Is this what is being heard?

A few more details about how, when, circumstances, etc., would be useful.

 

[Derek1875]

Hi i always reverse into parking spaces so it probs isn't to do with the cold only noticed it this bad after having front discs / pads fitted now it's every time i reverse into a space the noise starts i've even started taking two half turns into spaces to avoid hearing the noise lol Thanks for the feed back guys

 

[portland_bill]

only noticed it this bad after having front discs / pads fitted

There's the clue.

Pads could be tight in the calipers, so rubbing on the discs instead of retracting properly.
Material could be causing it, are they a cheap brand?
Need to get the pads looked at.

 

[Avaxbox]

check the brake back plates they always rub against the disc on the bottom just push them away a bit then you'll be fine.

 

[Derek1875]

Thanks everybody for the feedback i'll get it looked at