Loud noise upon braking

[Itsaplane[_2_]]

Making a relatively low-energy landing in my DG-300 (s/n 3E1) on
Sunday, I modestly applied the brakes and instantly heard a loud
buzzing (?) noise. I released the brakes, the noise stopped, and I
reapplied the brakes and heard no noise with normal braking power.

This is a TOST drum brake.

A cursory inspection of the main wheel/brake assembly revealed nothing
out of the ordinary -- though the drum appears to be dragging on the
wheel at various points around its turn (*very* softly dragging, i.e.,
not turning friction-free) -- not sure if it was this way before.

Should I investigate this further?

Thanks,

Eric

[Dave Nadler]

On Jun 16, 10:56*am, Itsaplane > wrote:
> Should I investigate this further?

Na, just turn the radio up.

[Andy[_1_]]

On Jun 16, 10:56*am, Itsaplane > wrote:

> This is a TOST drum brake.
>
> Should I investigate this further?

I'd assume that whatever was buzzing either died or escaped.

Perhaps some rusting of the brake drum caused a resonance which went
away after the rust was polished off. How long since the last brake
usage and is the glider in a damp environment?

You could try disconnecting the brake cable so the actuating arm is
fully relaxed and see if the rubbing goes away. If it does not, you
may need to pull the wheel and inspect the brake plate, shoes, and
drum. If it does, you may need to adjust the cable or the arm
position. The best geometry is for the arm and cable to be just short
of a 90 deg angle at max brake application and the shoes should not
rub when there is no brake application.

I always applied full brake as the wheel spindle bolt was tightened.
This ensures the brake plate is centered if there is any free play.

I'm assuming you dismantle it every year and clean and lubricate the
pivot points and the cam faces.

Andy

[Terry Mc Elligott]

You might want to contact Michael "Mercury" Morse at Vintage Brake, in
Sonora, California ... here:
http://www.vintagebrake.com/

should your TOST brake cease stopping the DG quite as effectively. One
of those very handy contacts to keep in mind.

Terry Mc Elligott
DG-200 / C-GVLB

On Jun 16, 1:56*pm, Itsaplane > wrote:
> Making a relatively low-energy landing in my DG-300 (s/n 3E1) on
> Sunday, I modestly applied the brakes and instantly heard a loud

> buzzing (?) noise. *I released the brakes, the noise stopped, and I
> reapplied the brakes and heard no noise with normal braking power.
>
> This is a TOST drum brake.
>
> A cursory inspection of the main wheel/brake assembly revealed nothing
> out of the ordinary -- though the drum appears to be dragging on the
> wheel at various points around its turn (*very* softly dragging, i.e.,
> not turning friction-free) -- not sure if it was this way before.
>
> Should I investigate this further?
>
> Thanks,
>
> Eric