Catching noise when braking

[morrisminor]

If I brake gently I can hear catching I think from the rear, with each rotation of the wheel,   if I brake firmly it doesn't seem to do it ? Any ideas everyone ?

[Charles Levien]

If I brake gently I can hear catching I think from the rear, with each rotation of the wheel,   if I brake firmly it doesn't seem to do it ? Any ideas everyone ?

Stick to braking firmly

[David Stepney]

Check that the rear wheel nuts are firmly nipped up. I had a similar problem that turned out to be slack wheel nuts!

[Chris KC]

Not sure what you mean by 'catching' but most likely your drums are slightly oval such that under light pressure they only contact with the shoes twice per revolution. A7 drums are so lightly constructed that skimming them is liable to make matters worse.

Drum distortion may also be induced if the joint faces are not quite flat - again I would not remove metal but it may be worth checking for obvious high spots and distortion in the joint.

To some extent the above is inherent in the A7's  'lightweight' design and may be hard to eliminate altogether.

["Slack Alice" Simon]

Probably just some minor mis-alignment of the brake shoes.

But the answer to your question prompts a reminder about something that should be done regularly:

 before checking wheel nuts, have the wheels off and check the half shaft nuts.

I have left off the wheel centre trims (so I don't need to take the wheels off) , and I don't fit the split pins, and every month or so I put a socket on the nuts, with a long extension to a ratchet

spanner, support the outside end on an axle stand, and then stand on the end of the spanner handle.

That keeps them tight and helps avoid more serious problems later.

[morrisminor]

Thanks Slack, I don't get a clonk when moving off which I'm lead to believe is indicative of not tight half shaft nuts ? Worth a try though.
So you leave the wheel on to tighten and car on ground ? Sorry what do you put on an axle stand ?

[Howard Wright]

Hi Morrisminor 

Make sure the back plates have not be knocked in to the drum.  On pre Girling cars the back plates are quite flimsy and are often quite badly dented. 

Jack the car up and try spinning the wheel with the brake cable slack and then pulled up slightly.

Cheers

Howard