Binding Drum. PLEASE HELP !

Hi again folks,

You may have enjoyed my earlier thread about yesterday's MOT failure issues:
http://www.landyzone.co.uk/lz/f6/mot-misery-77246.html

Today, I (eventually!) managed to remove both front brake drums. In fact, the MOT had failed the front nearside brake for binding... although originally he mistakenly told me that it was a rear.

Jacked up - the front offside wheel turns without any binding or noises at all.. no problem. When I tried to turn the nearside, the wheel would only turn with some effort. I know from driving that this binding usually goes by the time I get down the end of the road - which is why I had been lazy and not looked at it before.

When I got the drums off... I was pleasantly surprised... apart from some build up of dust inside, both had dry wheel cylinders with good rubber boots and even wear on the shoes either side.

I cleaned both sides with LOTS of brake cleaning spray and re-fitted the drums with new holding screws.

Unfortunately, the nearside STILL binds - BUT.. only through two thirds of a rotation. I can turn the wheel easily through one third of arc of a rotation - but then it starts to bind (turning in either direction). I tried turning the adjuster bolt connected to the snail cam (behind the backplate) - but after many small turns (clockwise and then anticlockwise) it seemed to make no difference at all (better or worse!).

So I am puzzled as to what could be causing the binding... could it be the drum itself is warped ??

I have attached some photos below:












Any ideas ??

What's the top spring connected to on the adjuster side?

Looks to me like a stuck piston - the one sticking out a bit?

You MUST be able to push the pistons in by easy finger pressure.

If not they are stuck = binding brakes.

The whole lot looks dry dirty and rusty and not looked after. Strip the lot, use plenty copper grease on the pivots and contact points and adjuster wedges, and clean it.

CharlesY

CharlesY

Davec said:

What's the top spring connected to on the adjuster side?

Click to expand...

Hi,

In the adjuster side, the spring connects to the peg in the shoe... the other end of the spring of course goes to the peg on the backplate.

can you see the cams turning ?

CharlesY said:

Looks to me like a stuck piston - the one sticking out a bit?

You MUST be able to push the pistons in by easy finger pressure.

If not they are stuck = binding brakes.

The whole lot looks dry dirty and rusty and not looked after. Strip the lot, use plenty copper grease on the pivots and contact points and adjuster wedges, and clean it.

CharlesY

CharlesY

Click to expand...

You might well be right.. I just took off the other (good) drum and the piston do seem to be further in. I will get out the copper grease and cleaning brushes !

OK.. this will sound like a really stupid question... but are BOTH pistons meant to move - or just the trailing shoe piston?

I started to strip the wheel cylinder and used a clamp to push the pistons in... the trailing piston moved - albeit stiffly (looked very dry so gave it copper grease and it moves easily now).... the leading shoe piston seemed to be stuck fast.

Since cleaning and copper greasing all that I can, the drum doesn't bind anymore.... but I can't take for a spin yet as I have started stripping the shocks to renew their worn bushes !!

Both are meant to move