The drivers side caliper on my 1993 Eunos makes a loud knock when I lighly apply the brakes. The sound is very much like a tap of metal on metal. It doesn’t happen when braking hard. Brake pads are 12 months / 9k miles old & slider pins well greased / contact points with copper grease. Also sometimes the drivers side brake disc does not clean up after the car being stood up - for example after 20 odd miles the passenger side disc was shiney but the drivers side still had signs of surface corrosion.
Has anyone had any experience of sticking brake calipers that made a knocking noise?? Any other ideas what it could be?
I too have a 1993 Eunos with exactly the same ‘quirk’! I took the car to my mechanic who stated that he had the same problem with his Eunos also when he owned one. He told me that he stripped it all down and replaced pretty much everything that could be replaced and after a week the same noise started up again!! He is convinced that this is just something that should be seen as ‘character’ and nothing to worry about.
Sometimes I get no knock, sometimes it’s every time I brake. sometimes it’s just one side or the other and sometimes it’s both!!
It is very noticable and rather annoying. My wife is sure that the car is falling apart.
1996 Eunos, does exactly the same from the rears, i suspect it’s play somewhere, pin/pads or something…passed its mot and seems to brake fine so i won’t be worrying.
Oddly my main car Renault Scenic starting knocking when braking after replacing discs and fitting some aftermarket pads, did it for about a year before i realised it was the pads moving in the caliper, changed them to Renault ones for £40 and knocking vanished. Guess the aftermarket ones were just badly made thus allowing play.
Tapping under light pressure, yes, we used to get lots of things like this. Often due to distortion and/or corrosion on the disc face or edge. Remember there’s 2 sides of the disc to check. Can be the pad is just a little loose in the carrier, the carrier can wear or sometimes the pad friction material itself can even be loose on the pad metal backing. Often scraping the corrosion off the edges of the disc by rotating against a screwdriver then reassembling with copper slip on the pad edges and backs would do the trick. These days I’d strip and clean the callipers and reassemble with new discs and pads.
If it is a loud knock I’d definitely strip it, could be other stuff like loose calliper bolts, loose wheel nuts even, wheel without centre spigot, supsension ball joint etc.
it’s your pads moving in your carriers, good in one way as it shows that pads hasn’t seized…bad due to the noise, make sure all the springs are in place, or replace the pads and the fitting clips/springs, or just turn the music up! (before i get shout at for that last comment it a joke!)
I can confirm that all the springs & clips are in place, but the pads don’t have shims fitted… Would this cause the noise?? Interestingly, when I asked ‘her in doors’ to gently press the brake pedal while I rotated the disc against the friction I noticed that the pad did move slightly upwards - not sure if that is to be expected or not?? Also when I changed the pads I used Ferodo premier pads which came with their own fitting kit (clips / springs). Stupidly I chucked the old ones out & used the ones that came with the pads. Perhaps they’re not fabricated to the same tolerance?
I’ve got new discs & pads to go on, just hoping that I don’t have to buy new calipers as well!! Only just changed the rears as they were seizing up…
Yep, fitting shims would help. A few pads now come with adhesive shims (eg. Axiss pads), and Bendix sell “Blue Goo”, which is a shim you paint on. The clonking pad, if this is the cause, is not going to cause any issues, except be very annoying.
