Knocking from rear brakes under light braking

[andy625uk]

Been noticing this for a few days, when I'm braking lightly, like in a traffic queue I get a rythmic knocking from the rear right hand side. If I speed up and brake harder it's fine. Doesn't knock when accelerating, just braking.

I know I've got a leaky shock that side, but surely that would rattle rather than give a rythmic sound. As soon as I let off the brakes it's fine.

Gonna get under there and have a push-pull, check lug nuts etc. Anyone else had this. It's rear drums, no abs and shoes are getting on a bit at 75k miles. Haven't had a look at them recently but passed the balance test at the last inspection.

 

[andy625uk]

Can't see anything wrong apart from perished lower shock bushes. there doesn't seem to be any play in them anyway. I suppose I'll have to take the drum off and have a look.

 

[theterminator93]

As I was pondering this one I was thinking the only way to really figure it out would be to yank the wheel and drum and poke around. There's lots of stuff in there that might be causing what you're describing - worn out shoes, misadjusted mechanism etc.

 

[andy625uk]

I just did that after doing the other bits today, and the only thing that Inoticed was a slightly leaky cylinder. Couldn't find any play in anything. Anyway, I put everything back together and went for a test drive. After getting the brakes nice and hot, and going forward and back a few times in an empty carpark it hasn't done it at all......yet.

I was wondering whether its my ears (which don't work very well at the best of times) are playing tricks because my front rotors are slightly warped and when they're hot I get a bit of pulsating in the brakes. I'm now wondering (hoping) whether one of the joints I've replaced, either the uca, or one of the endlinks, even though I couldn't find any play in any of them, was the cause of the noise.

It occurred to me the other night that it only happened at a point where the front brakes were pulsating and I'm thinking my hearing was making me think it was coming from behind me when in fact it was coming from in front.

I'll let you know in due course