Fiesta mk8 - 2.5 year old problem - l/h brake grinding
Discussion
2021 Mk8 Fiesta. 40k miles. manual, 1.0 turbo
Issue = front left brake grinding from 20mph to zero. whats been tried so far >new pads and discs multiple times, new slider, new caliper, new brake hose, new brake pad springs, new knuckle, new wheel bearing, been to main dealer twice and multiple smaller garages. wheels changed over. everything initially looked original, no crashes, hit the kerb etc and a well treated car.
the issue is definitely rotational - touch the brakes and it grinds on each wheel revolution and its very loud. doesnt matter if turning left or right. no vibration when driving normally, steers straight, a perfect car otherwise etc etc. any ideas?
when i say grinding / brakes rubbing - its more of a squeaky noise as you come to a stop. any help appreciated thank you. not sure how to add a pic in.
Issue = front left brake grinding from 20mph to zero. whats been tried so far >new pads and discs multiple times, new slider, new caliper, new brake hose, new brake pad springs, new knuckle, new wheel bearing, been to main dealer twice and multiple smaller garages. wheels changed over. everything initially looked original, no crashes, hit the kerb etc and a well treated car.
the issue is definitely rotational - touch the brakes and it grinds on each wheel revolution and its very loud. doesnt matter if turning left or right. no vibration when driving normally, steers straight, a perfect car otherwise etc etc. any ideas?
when i say grinding / brakes rubbing - its more of a squeaky noise as you come to a stop. any help appreciated thank you. not sure how to add a pic in.
car has been to 2 main Ford dealers - and multiple small garages (including the MOT garage - who passed the car but said 'oh yer the car does make alot of noise upon braking - we put it up on the lift but found nothing obviously wrong - but yer it is very noisy'
ive also had a good go at this car - with friends having a look too. all garages blame the pads and discs - but i say look they are brand new - then they are stumped.
ive also had a good go at this car - with friends having a look too. all garages blame the pads and discs - but i say look they are brand new - then they are stumped.
You describe it as a squeal as you come to a stop? have the pads and sliders been sensibly lubed in the appropriate places during assembly.
A squeal is quite often a high frequency vibration of the back of pad against the piston and/or the edges of the pad against the caliper itself, sometimes removing the pad and looking for shiny spots can reveal the noise source, a wipe with whatever brake lube you choose usually cures it, i won't suggest which lube because opinion as to what should and shouldn't be used varies a lot.
The pads are operating just inside the outer edge of the disc? if for some reason the pad friction area is forming a ridge outside the egde of the disc that can cause some noises.
A squeal is quite often a high frequency vibration of the back of pad against the piston and/or the edges of the pad against the caliper itself, sometimes removing the pad and looking for shiny spots can reveal the noise source, a wipe with whatever brake lube you choose usually cures it, i won't suggest which lube because opinion as to what should and shouldn't be used varies a lot.
The pads are operating just inside the outer edge of the disc? if for some reason the pad friction area is forming a ridge outside the egde of the disc that can cause some noises.
yes a grinding type squeal. the main dealers - i think copper ease and ive seen something else on their too. its good for about 5 miles then noise returns. pads sit nicely on the disc so no wear there. the only thing ive really noticed is - yes ive taken wheel off , changed this that and the other - but im not sure that changing anything fixes anything. common denominator here is that the car has been up on the jack with the steering , suspension , caliper etc all off of the ground hanging !!!!!! as i have had everything changed the only time it ever stops for a bit is when its been hanging. basically all weight off that side of the car.
Mystifying. It's been apart many times, in many different hands, besides which you've changed literally everything, yet the noise remains exactly the same! There would be other things to look at (eg driveshaft, CV boot rubbing on itself) were it not for the fact that it only occurs when you're applying the brake.
Edited to add: At this point, clutching at straws, I'd be doing a complete 'spanner-check' on all bolts on that corner, everything, including subframe bolts, strut bolts, top mounts (all of which arguably get 'loaded' during braking, and 'unloaded' whilst the car is jacked.).
Edited to add: At this point, clutching at straws, I'd be doing a complete 'spanner-check' on all bolts on that corner, everything, including subframe bolts, strut bolts, top mounts (all of which arguably get 'loaded' during braking, and 'unloaded' whilst the car is jacked.).
Edited by TwinKam on Thursday 19th March 19:13
Has the calliper mount been changed?
I ask because if there is play/wear in the holes the sliders go in it could be skewing the calliper on braking.
One indicator of the above could be uneven (not fully flat over the full pad face) wear on the pads, which may only be evident on very close inspection.
I ask because if there is play/wear in the holes the sliders go in it could be skewing the calliper on braking.
One indicator of the above could be uneven (not fully flat over the full pad face) wear on the pads, which may only be evident on very close inspection.
Are the pads properly bedded in? - Give the car some really good hard brakes, up to speed, brake, up to speed, brake (please dont try do it with any traffic around you) - if you do get it properly hot then some gentle driving before you park up would be advisable.
Get a good lot of heat into everything, it is designed to get hot.
Really helped with a previous car, brakes felt a lot better for a few weeks after I got them hot.
Get a good lot of heat into everything, it is designed to get hot.
Really helped with a previous car, brakes felt a lot better for a few weeks after I got them hot.
Yes - pads definitely properly bedded in. yes caliper mount been changed (got this from autodoc and did this myself - did caliper at same time) - pins came in the kit too - put these in too and greased them. ive done the brake test many times. its silent for at least the first 7 or 8 hard brakes after changing - then the noise slowly starts to appear. but i only believe its not grinding for the first 7 or 8 times because the car was up on the jack / axle stands and the suspension was hanging. so im going to go after lower joints , tie rods etc now. all bushes look sound though to me. im assuming cv boot and driveshaft is ok as Ford changed the knuckle and wheel bearing.
marks1978 said:
Yes - pads definitely properly bedded in. yes caliper mount been changed (got this from autodoc and did this myself - did caliper at same time) - pins came in the kit too - put these in too and greased them. ive done the brake test many times. its silent for at least the first 7 or 8 hard brakes after changing - then the noise slowly starts to appear. but i only believe its not grinding for the first 7 or 8 times because the car was up on the jack / axle stands and the suspension was hanging. so im going to go after lower joints , tie rods etc now. all bushes look sound though to me. im assuming cv boot and driveshaft is ok as Ford changed the knuckle and wheel bearing.
You will find it if you look hard enough.Based on what you say, you need the car up with weight on the wheels so on ramps/blocks of wood etc. and you will need an apprentice to apply brakes while you are looking underneath & applying torque with a persuader bar.
I've just re-read your original post...
Again, previously,
But essentially, start again with an open mind, wheel off, wheel nuts back on (to secure the disc), then observe what moves as the brake is applied, strip it, look for witness marks... good luck.
marks1978 said:
{snip snip}...the issue is definitely rotational - touch the brakes and it grinds on each wheel revolution
But now,marks1978 said:
{big old snip}so I'm going to go after lower joints , tie rods etc now.
With respect, I think you need to stand back, breathe in deeply, and stop throwing parts at it. And particularly those parts, which have nothing to do with "rotational" noise/ noise "on each revolution". Again, previously,
marks1978 said:
I'm assuming cv boot and driveshaft is ok as Ford changed the knuckle and wheel bearing.
And assume nothing, 'Ford' (your local franchised main dealer?) will have put their 15 yr olds on it, so that's no guarantee of it having been done properly, or adjacent components being checked thoroughly or, for that matter, them even comprehending how it all works together. Maybe, with that in mind, checking the tightness of the hub (driveshaft) nut might be a good idea! But essentially, start again with an open mind, wheel off, wheel nuts back on (to secure the disc), then observe what moves as the brake is applied, strip it, look for witness marks... good luck.
marks1978 said:
yes a grinding type squeal. the main dealers - i think copper ease and ive seen something else on their too. its good for about 5 miles then noise returns. pads sit nicely on the disc so no wear there. the only thing ive really noticed is - yes ive taken wheel off , changed this that and the other - but im not sure that changing anything fixes anything. common denominator here is that the car has been up on the jack with the steering , suspension , caliper etc all off of the ground hanging !!!!!! as i have had everything changed the only time it ever stops for a bit is when its been hanging. basically all weight off that side of the car.
That 5 miles of silence suggests a pad vibration issue to me.If twer mine i would exercise the pistons in their bores several times (one side at a time), with the help of an assistant pump the piston out a fair amount, push back in, rinse and repeat, you can do this alone by removing the pad that doesn't contact the piston and push the piston out till it stops, rinse and repeat.
If the piston is hard to push back, its permissable to gently peel back the dust cover and inject some correct brake grease onto the piston itself, continue exercising till no longer hard to return.
Then apply lube of your choice to the edges of the back plates where they touch the caliper, and behind the back plates where they contact the piston and caliper respectively, you should have perfect braking and quiet running till the next brake service.
Clean and lube the sliders properly.
Many brake issues are purely down to poor brake servicing, annoys me no end, the far too typical squirting brake cleaner about willy nilly by bodgit and scarper only serves to remove any existing lube a proper mechanic once applied.
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