Braking fault

300TDI '94 L Reg.

pulling hard to nearside on braking.

looked at front brakes both sides. seem ok and both operational when
checking without servo. (engine off). Plenty of pad and discs ok (new about
2 years ago)

But on both sides no anti rattle strips between the bolts and the tops of
the disc pads. so called anti rattle springs in place on bolts though.

Is there any other cause I could be overlooking. Because both breaks stopped
me rotating the hub by hand when servo less pressure placed on break pedal I
am assuming the pistons are free to move in the calipers.

Just thought. could a fault on the rear brakes cause marked deviation on
breaking?

Will try that anyway and let you know

Cheers all

> 300TDI '94 L Reg.
> pulling hard to nearside on braking.
>

> But on both sides no anti rattle strips between the bolts and the tops of
> the disc pads. so called anti rattle springs in place on bolts though.
>

Be a bit careful about these. They actually stop the pad rotating in
relation to the calliper. If absent, the pad can rotate and the pad
backplate can then rub against the 'hub' of the disc. Discs can be
machined off!

> Is there any other cause I could be overlooking. Because both breaks stopped
> me rotating the hub by hand when servo less pressure placed on break pedal I
> am assuming the pistons are free to move in the calipers.
>
The only true test is that the pads retract (i.e. braking ceases) when
brake pressure, however applied, is removed. The servo is irrelevant in
this regard and will not affect brake balance. You could still have
sticky pistons in any calliper - front or rear.

> Just thought. could a fault on the rear brakes cause marked deviation on
> breaking?
>
Yes.

Someone else will tell you about suspension/tyre-related issues that can
produce imbalanced braking.

On or around Mon, 13 Dec 2004 20:15:58 -0000, "John" <[email protected]>
enlightened us thusly:

>300TDI '94 L Reg.
>
>pulling hard to nearside on braking.

an offside brake isn't up to scratch. Being as they're 4-pot calipers on
the front your test is not conclusive. Take it to an MOT place and ask if
they will put it on their brake-tester. Pick your garage carefully and
they'll do it for free, if they're not busy.

>But on both sides no anti rattle strips between the bolts and the tops of
>the disc pads. so called anti rattle springs in place on bolts though.

anti-rattle things won't affect the braking performance, especially by not
being there.

>Just thought. could a fault on the rear brakes cause marked deviation on
>breaking?

yes.

"John" <[email protected]> wrote in message
news:[email protected]...
> 300TDI '94 L Reg.
>
> pulling hard to nearside on braking.
>
I've had this problem which cures by very heavy multiple applications of the
brake pedal while stationary. On mine it's a sticky calliper which seizes up
every 6 months or so. Once cured it's Ok again.

TonyB

Thanks for this TB.: -

"I've had this problem which cures by very heavy multiple applications of
the
brake pedal while stationary. On mine it's a sticky calliper which seizes up
every 6 months or so. Once cured it's Ok again."

It works a bit for me, but more like just for 6 minutes not 6 months.

Bit bullet and off with the wheels and out with the pads.

Yes its a very weak outboard cylinder on rear o/s caliper.

Try what I may it just doesnt respond with the same pressure as the inboard
cylinder.
And the disk it pretty bad too (although plenty of pad wear left)

So. New disk and ? new caliper if a repair kit doesnt free it up.
Weird though how the piston moves ok but just doesnt transmit the correct
pressure.
Any ideas?
Also I'm guessing if I need to replace one disc I should do them both.
NB no brake fluid loss.





"John" <[email protected]> wrote in message
news:[email protected]...
> 300TDI '94 L Reg.
>
> pulling hard to nearside on braking.
>
> looked at front brakes both sides. seem ok and both operational when
> checking without servo. (engine off). Plenty of pad and discs ok (new
about
> 2 years ago)
>
> But on both sides no anti rattle strips between the bolts and the tops of
> the disc pads. so called anti rattle springs in place on bolts though.
>
> Is there any other cause I could be overlooking. Because both breaks
stopped
> me rotating the hub by hand when servo less pressure placed on break pedal
I
> am assuming the pistons are free to move in the calipers.
>
> Just thought. could a fault on the rear brakes cause marked deviation on
> breaking?
>
> Will try that anyway and let you know
>
> Cheers all
>
>

In article <[email protected]>, John wrote
>
> So. New disk and ? new caliper if a repair kit doesnt free it up.
> Weird though how the piston moves ok but just doesnt transmit the correct
> pressure.
> Any ideas?
> Also I'm guessing if I need to replace one disc I should do them both.
> NB no brake fluid loss.
>
>

Always replace the disks in pairs and fit new pads at the same time. If
you don't you'll have the same unequal braking forces you're trying to get
rid of.

You may find you need to replace the calipers as well. Where the pistons
have been exposed they rust and won't go back in without wrecking the seals.

I needed new disks on the front of the 110 this year and it ended up with
new disks, pads and calipers for that reason.

--
simon at sbarr dot demon dot co dot uk
Simon Barr.
'97 110 300Tdi.