my rear disc brakes have lost their backplates through corrosion and
agro in the ice etc.

Are they "required" or will it be OK without the faff of replacing
them? IOW what are they for and do they need replacing?

ta
Jim K

Jim K gurgled happily, sounding much like they were
saying:

my rear disc brakes have lost their backplates through corrosion and
agro in the ice etc.

Are they "required" or will it be OK without the faff of replacing them?
IOW what are they for and do they need replacing?

You'll probably find that the handbrake mechanism and perhaps even the
calipers are more prone to seizing, and that the handbrake is less
effective after a wet m'way run. You may even find the inner side of the
rear disks getting pitted through corrosion.

On Dec 11, 4:58*pm, Adrian wrote:
Jim K gurgled happily, sounding much like they were
saying:

my rear disc brakes have lost their backplates through corrosion and
agro in the ice etc.

Are they "required" or will it be OK without the faff of replacing them?
IOW what are they for and do they need replacing?

You'll probably find that the handbrake mechanism and perhaps even the
calipers are more prone to seizing, and that the handbrake is less
effective after a wet m'way run. You may even find the inner side of the
rear disks getting pitted through corrosion.

Wet brakes have no effect at all.


NT

On Dec 11, 5:01*pm, Tabby wrote:
On Dec 11, 4:58*pm, Adrian wrote:

Jim K gurgled happily, sounding much like they were
saying:

my rear disc brakes have lost their backplates through corrosion and
agro in the ice etc.

Are they "required" or will it be OK without the faff of replacing them?
IOW what are they for and do they need replacing?

You'll probably find that the handbrake mechanism and perhaps even the
calipers are more prone to seizing, and that the handbrake is less
effective after a wet m'way run. You may even find the inner side of the
rear disks getting pitted through corrosion.

Wet brakes have no effect at all.

NT

80% of braking force happens on the front wheels, so back brake
failure has limited effect on stopping ability. But the handbrake is
rear wheels only, and MOT inspectors prefer brakes on 4 wheels
nowadays.


NT

Tabby formulated the question :
Wet brakes have no effect at all.

Wet drums do, wet disks do not.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Dec 11, 5:04*pm, Harry Bloomfield
wrote:
Tabby formulated the question :

Wet brakes have no effect at all.

Wet drums do, wet disks do not.

When I got my rear drums & front discs wet years ago, there was no
braking whatever. Made things fun.


NT

In article ,
Harry Bloomfield wrote:
Tabby formulated the question :
Wet brakes have no effect at all.

Wet drums do, wet disks do not.

Not actually true. I did a conversion to discs from drums on an old MG
ages ago and didn't bother with the backplates. The brakes didn't work in
heavy rain at even motorway speeds. Backplates cured things.

--
*Ever stop to think and forget to start again?

Dave Plowman London SW
To e-mail, change noise into sound.

Tabby wrote:
On Dec 11, 5:04 pm, Harry Bloomfield
wrote:
Tabby formulated the question :

Wet brakes have no effect at all.
Wet drums do, wet disks do not.

When I got my rear drums & front discs wet years ago, there was no
braking whatever. Made things fun.


NT

neither work till they dry out.

Drums don't dry out well - the water is spun to the rim. On discs its
spun OFF the rim.

On 11/12/2010 17:03, Tabby wrote:

80% of braking force happens on the front wheels, so back brake
failure has limited effect on stopping ability. But the handbrake is
rear wheels only, and MOT inspectors prefer brakes on 4 wheels
nowadays.


That 80% is a bit variable, depending on the car. It's probably about
right for a standard front-wheel-drive car.

A few cars have front wheel handbrakes. Xantia is one IIRC...

http://en.wikipedia.org/wiki/Parking_brake

"The Alfasud, Saab 99s, Pre-Facelift 900's, the Citroen Xantia and most
early Subarus applied the handbrake force to the front wheels"

Andy

"Andy Champ" wrote in message
...
On 11/12/2010 17:03, Tabby wrote:

80% of braking force happens on the front wheels, so back brake
failure has limited effect on stopping ability. But the handbrake is
rear wheels only, and MOT inspectors prefer brakes on 4 wheels
nowadays.


That 80% is a bit variable, depending on the car. It's probably about
right for a standard front-wheel-drive car.

A few cars have front wheel handbrakes. Xantia is one IIRC...



Must be a Citroen thing. The 2CV had a variation of front wheel brakes
where the brake drums were mounted inboard on the driveshafts alongside the
tranasmission unit. Easy to work on because you could reach them from
under the bonneet - no wheels to jack up and remove.
--
Tinkerer

"Tinkerer" gurgled happily,
sounding much like they were saying:

A few cars have front wheel handbrakes. Xantia is one IIRC...

Must be a Citroen thing. The 2CV had a variation of front wheel brakes
where the brake drums were mounted inboard on the driveshafts alongside
the tranasmission unit. Easy to work on because you could reach them
from under the bonneet - no wheels to jack up and remove.

Apart from the fact that on drumbrake 2cvs it means that the handbrake is
as good as the footbrakes, since it uses the same shoes, on hydraulic
Citroen's it's necessary due to the rear suspension design.

As the car sinks whilst parked, the wheelbase lengthens. If the handbrake
was on the rear, and it was left in gear (FWD, remember), you'd be
putting stress on the 'box and/or rear brakes as they'd end up holding
the entire weight of the car up. Press the clutch or take it out of gear
before you start the engine, and it'll drop to the bumpstops with a right
ol' bang.