Ford Fiesta

[MovingShadow]

Question for some of the mechanic goeroe's here.

My girlfriend has a second hand Ford Fiesta 1.6 diesel from 2010.

It's a nice little economic car but lately it has some small problems.

When breaking (hard) the car vibrates. You can feel it in the steering wheel. Does this mean the brakes are getting worn or maybe a warped brake disc?

Also in some conditions, there is a bit more noise coming from the engine bay than in some conditions. Especially when the AC is working. When turning it off, it sounds less loud. Feel like a fan or something making some noise.

Car is from 2010 but has racked quite some miles. It's around 118000 km's.

 

[oscar]

you are correct man. the brake discs could be warped, although this isn't very common but you any garage can check this for you by using a Dial Test Indicator (you could do a DIY version by using a straight edge and feeler blades but this won't be so accurate...just place the straight edge over the face of the discs and if you get anything more than 0.04 then you're discs need to be binned)

other problems could be worn brake discs - down to the metal, or to the wear indicatior. this would feel like a metalic scraping noise with vibrations felt through the steering wheel.

my suspicions would point to the brake discs though, check their thickness and compare them to the minimum disc thickness which i'm sure you could find somewhere online. when discs reach their minimum thickness, they have lost so much mass that their capability to dissipate the frictional heat created through braking that they can deform and loose their shape.

an outside cause could be a problem with your ABS system, but you'd have a fault code for that so i wouldn't worry about this whatsoever.

.... on the AC note, it sounds like you've got an AC clutch on it's way out buddy. easy enough job to change, i'm sure you could do it!

 

[Anthony1664]

Would say the pads are too worn and have damaged the discs, I picked up a 2nd hand Mondeo ST last May and the rear pads and discs were shot and the vibration under braking was something else. £130 saw it sorted

 

[Dubz]

my twingo has started doing this. Like it judders when heavy breaking. Pads and discs have only had 3k miles on them...

 

[oscar]

yeah anthony that seems to be the most common problem of damaged discs. some garages are too lazy to check the current discs the correct way, and will just look for scoring etc and may notice the pads are very worn and and will just change the pads over without touching or measuring the discs the rule of thumb is that if you feel it through your steering wheel, then it's something directly linked to your wheel hub which could include suspension > braking system > steering as this is all connected to the hub. but with the pulsation that mattheo (i can never remember names lol) is feeling, it sounds like it's pulsating at a certain frequency and varying with speed which indicates a rotating item. the pulsations are the high points from the brake disc warping slightly, the slower the car comes the slower the vibrations will get so on so forth

i'll get an how to - using a Dial Test Indicator to check your brake discs, thread up next week or therabouts guys incase anyone wants to buy one for future purposes to save some $£$£ in garage labour. they don't cost very much

 

[singlespeed]

i'll get an how to - using a Dial Test Indicator to check your brake discs, thread up next week or therabouts guys incase anyone wants to buy one for future purposes to save some $£$£ in garage labour. they don't cost very much

ive just got a cheap ebay one ~£20, complete with magnetic stand. I don't expect it to be accurate enough for measurements suitable for machining and being able to say its x.xxmm out of true However, getting a good idea of a variation away from flat should be fine.

 

[oscar]

that's the one, as long as it gives you a fairly close reading then it'll do you all for brake disc measuring 0,04 mm is usually the maximum disc run out to work by as a universal rule of thumb. what is yours accurate to neil? is it 0,01 or 0,001 ? i don't get to use these little tools as often as i'd like to so i cant quite remember off the top of my head the usual accuracy's that they work to

 

[singlespeed]

https://www.ebay.co.uk/itm/120985547302?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D120985547302%26_rdc%3D1
10mm range and 0.01mm accuracy. It was the it was the free postage that sold it as we normally get humped an extra £10-15 for delivery

It actually reads up to 13mm, just going round the scale for a second lap. Accuracy wise doesn't seem too bad, registering cheap (really thin) tin foil at less than one division, so <0.01mm which is probably right and paper post it notes at 0.08mm which again is close enough