Loud hum drone when reversing 1999 v70
 

Hi all I have a 1999 2.4 n/a petrol v70 ..
when I put it in reverse (manual) ,and go back there is a loud hum/drone .
sounds like a brake sticking kind of noise..
it's not the hand break ,as I've slackened it right of to eliminate that . Is it possible for the caliper to be sticking on due to rust (like the phase 2 were prone too)) if so is a strip down and clean/regrease an easy thing to do on them..or am I better of getting rebuilt ones if I can find them

It could still be handbrake shoes chafing, there's a known fault where the linings come un-bonded from the metal shoe, can cause this and other problems, and backing off the adjustment won't solve it.

Only way to find out is to whip off the disks and have a look - you can check the rear calipers and pads while you're at it of course. Not a difficult job.

Well worth checking this, as if I'm right then the linings could become completely detached and cause jamming, binding or overheating even going forwards, and it'll fail an MoT brake test too - these handbrakes are a bit marginal even when in good nick.

What Luxobarge said.It's brake related .

Yep, we had this with our S70. The brake shoes in the rear drums (only used of course for the parking brake) started to fall apart. Then one morning the Mrs drove a few yards down the road, in a cloud of blue smoke from the burning rubber, with one rear wheel completely locked. Bizarrely, in reverse the car was fine and the wheel turned with no problem. The linings on one shoe had come adrift. New shoes sorted it. Thankfully no other damage was done, apart from the scoring in the tarmac of our driveway!

Also, don't be tempted to adjust the handbrake cables inside the car, using the screw in the centre console. That's used to set things up approximately, but the final adjustment must be done at each wheel. It's a fiddly job, and a pain, but if it isn't done properly then in time the hand brake will fail.

Jack

Surely you should adjust the shoes up at the wheels first and then the cables by the nut in the centre console? At least that's the way I did mine recently.How much are re-furbed calipers as opposed to new ones? I paid just shy of £70 for new ones recently and as it was something of a rush job I didn't take the time to compare prices,so even new ones may be available cheaper than those I bought.

Perfect thankyou everyone for the replies ,, I will have a look behind the discs when I have the chance..also on saabs it was practice to back of the adjustment on the hand brake before moving to the hub..

There's a few threads on handbrake issues on here, but in short, as Luxobarge said delamination of the shoes is fairly common, they do very little other than hold the car once it's stopped so a lot of cars will still be on their original 20+ year old shoes. And as dippydog says when adjusting, like the Saab, fully slacken the cable adjuster at the lever before setting the shoes with the adjuster inside the drum/disc, then set the height and travel of the lever using the cable adjustment. I replaced the calipers, discs, pads and shoes on mine a couple of years ago as the shoes had delaminated and one caliper was sticking leaving the back of the disc severely rusted, unless you carry a lot in the boot regularly the load sensing valve in the brake system means the rear discs/pads don't do much work either.