This has been happening occasionally since I had new disks and pads fitted a while ago, especially on the right hand side, but is now happening more on the left hand side, and is getting more annoying! The inner brake pads seem to be rattling around every time there's a bump in the road, and making the annoying noise you hear in the video. Do you think the wrong pads were fitted, and which ones should I fit if so?
Please see short video presentation with sound on!:
Ta
Re: Annoying rattle from brake pads
Posted: Thu Apr 22, 21 5:50 pm
by Dave999
take em out
smear the back with copper slip
put em back in again
but while the caliper is off check the runout on the disk and check the wheel bearings are done up to spec
something could be knocking the piston/pistons back to give more space between pads and disk than is strictly necessary
loose bearings or warped rotor
can' t tell what type of caliper you have but if they are girling/girlock style you will have 1 piston
the caliper head slides on a claw and the caliper head and pads are all held onto that claw by spring clip plates that bolt down with half head bolts half headed because they'd rub on the wheel,rim otherwise
check the spring plates have the springy bit pressing on the caliper head the plates can fall apart leaving the robust plate bit springless..
Grilocks also have a spring steel z shaped spring to stop pads rattling
if its missing all you will see is a raised stamped section for it to fit into/under in the back plate of each pad
the kelsey type caliper is a slider also but it uses pins and bushes that bolt into the outer face of the claw
its also has some anti rattle shenanigans but i can't remember what, having swapped mine in 2004 for girlock style
if you have girlock style i have a brand new set in the garage and i can photo what you should have in respect to anti rattle bits
i seem to also remember in some cases you need to gently shove new pads in, because some of them have a bent over section of back plate made deliberately a little too wide.. again to stop them clacking about
and early ones came with a shim, same shape as the exposed area of the back of the pad that sat on the piston. the shim is cut/pressed to act like a big wavy washer type set up its basically a spring, again to stop pads rattling if you have this shim coat both sides with copper slip and the metal back of the brake pad.
don't get it on anything else
Dave
Re: Annoying rattle from brake pads
Posted: Thu Apr 22, 21 6:28 pm
by Dave999
i see they are new rotors
did you run them in
if they are 2 piece rotor studded onto hub they need a gentle run in
they also do if 1 piece hub and rotor but they don't tend to warp as much its harder to warp them
if the brakes work well enough and the peddle doesn't pulse under your foot they probably aren't warped. i.e might just be worrying you for no reason
Dave
Re: Annoying rattle from brake pads
Posted: Thu Apr 22, 21 6:44 pm
by mustangbooks
Thanks for the replies Dave,
I'm not particularly worrying, just find the noise annoying! Yes they are new disks etc, as the old ones were badly scored. I doubt they are warped, having had warped disks on an old Mondeo, which felt horrible.
I found the part number on the back of the caliper, they are Kelsey-Hayes. Looking up the part number, which appears to be KH86166, I'm not sure they're correct for a '73 Challenger? I think they're supposed to have a retaining spring / clip as an anti-rattle device as you say, but it's not present, and I can't see where that would fit. It also seems to only act on the outer pads, whereas the 'loose' ones on mine are on the inside. They only move in a front-to-rear direction, not side-to-side (as you may be able to see in the youtube video), so not sure there's any problem with the piston / lack of shims etc in that direction. I might try putting copper grease on them anyway, to see if that helps.
Couple of pics:
IMG_20210422_150443913.jpg (314.94 KiB) Viewed 6907 times
IMG_20210422_150533960.jpg (331.79 KiB) Viewed 6907 times
Re: Annoying rattle from brake pads
Posted: Thu Apr 22, 21 7:51 pm
by Derek
Andy. Have you got the anti rattle springs on the pins that go through the pads.
Re: Annoying rattle from brake pads
Posted: Thu Apr 22, 21 8:17 pm
by mustangbooks
Derek wrote: ↑Thu Apr 22, 21 7:51 pm
Andy. Have you got the anti rattle springs on the pins that go through the pads.
I'm not sure exactly where they would fit, but no, I can't see any springs. I can see that springs are supplied with rebuild kits etc., but can't see where to buy them seperately, if that's what I need.
IMG_20210422_200656000.jpg (332.1 KiB) Viewed 6898 times
IMG_20210422_200702649.jpg (331.1 KiB) Viewed 6898 times
they look like they fit on the pins press against the nylon bushing for the sliver version or a flat face on the claiper around the pin for the yellowed version and of course the pad........! stop it jigging about.
looks like the hooked U shaped bit fits downbehind the pad and is compressed, the U being necessary to allow it to go either side of the pin at maximum compresion while the O behind is around the pin
its a bit expensive to find out though as you might have 73 brakes and i don't know how to spot the difference
if i was taking a risk id get silver and tap em flat with a hammer if i needed to they appear to be pressed to fit around the end of one of the bushes
if anyone does know the differences between the calipers 70-74, you are good to go
copper slip might shut it up but as i say don't get it everywhere
Dave
Re: Annoying rattle from brake pads
Posted: Fri Apr 23, 21 8:14 pm
by mustangbooks
Thanks for all that Dave! At least I know I can get the springs from RockAuto without the pins. I found someone selling the postioners on eBay, and although they're more expensive than the ones you linked to, they did provide a diagram of where they go:
positioner.jpg (130.31 KiB) Viewed 6873 times
...still not sure they'll stop the inner pad from moving backwards and forwards, as they don't appear to touch them?
Re: Annoying rattle from brake pads
Posted: Fri Apr 23, 21 8:38 pm
by mustangbooks
I just took this video, which shows the inner pad seems to have too big a hole for the pin, so it moves back and forth. Not sure any of the springs or positioners I've seen would stop this?:
Edit: I think there might be a bushing missing. I'm thinking I might just squish some RTV sealant or similar into the hole either side of the pin, which would hopefully stop the rattle!
Re: Annoying rattle from brake pads
Posted: Mon Apr 26, 21 10:57 am
by Dave999
yep agreed the positioners are really about keeping the caliper centred onto the rotor, suppose it helps stop the caliper being biased to 1 pad or the other..
Mmm
do the pads both have the same sized holes and are they the same inner and outer? i.e have you got front in the back and vice versa
short of making a little bush for it.... yes stuck
unless combo of anti rattle springs and positioner just keeps the caliper tensioned slightly so that the pads are always driven against a hard stop, kinds seems wrong as the disks would get hot....