11 replies to this topic

[Gwyn]

Hi there, new to the forum but not to Fords
Problem with the brakes, ford focus ST170, coming to a stop from around 20-15mph to 0, you can feel the brake pedal pumping (not fast, around once a second). Is this an abs sensor fault or warped front discs, the car has just covered 27,000.
Any suggestions or experiences with this type of problem
Gwyn

[mintalkin]

90% sure it will be a warped disc

[Gwyn]

90% sure it will be a warped disc

thanks for that info mintaklin
I'll source some discs this week, my previous car did 127,000 (9" solid discs) miles with the same discs, so much for 300mm vented discs brakes

[mintalkin]

see if you can get hold of a dial gauge to check the run out of the discs before buying new just in case its something else

[Gwyn]

see if you can get hold of a dial gauge to check the run out of the discs before buying new just in case its something else

Hi mintalkin
What's the max +/- in mm/thou (run out) you would expect to get on a dial guage reading before rejecting the discs.
kind regards
Gwyn

[mintalkin]

anything above 0.1mm (0.004”).would most likely cause pulsating

[Gwyn]

anything above 0.1mm (0.004”).would most likely cause pulsating

Thanks again mintalkin.
Will borrow a DTI from work midweek, will post the result hopefully by the weekend.
regards
Gwyn

[Gwyn]

Thanks again mintalkin.
Will borrow a DTI from work midweek, will post the result hopefully by the weekend.
regards
Gwyn

DTI checks on each corner

Front off-side 0.03mm
Front near-side 0.03mm
Rear off-side 0.02mm
Rear near side 0.45mm

It was obvious when I jacked up the car (Rear-near side), that this was the culprud, the wheel was binding when Hand turned at one particular point, Further investigation showed a deviation of .45mm at this point for approx 12cm. Have ordered some discs today and hopefully put them on Tuesday evening. The brakes on this corner must have been running hot, hence affecting the performance & MPG.
Thanks again
Mintalkin
regards
G Jones

[mintalkin]

no problem glad you found the culprit

[Gwyn]

no problem glad you found the culprit

I fitted new rear discs and pads this afternoon, it solved the problem. Used Ford origional parts, worst job was to push back the piston in the caliper. Your suppose to use a special ford tool, I got away with a 4" G clamp, made for the job, allthough it required a lot of effort to push the piston back.
Happy motoring
ps Thank god for forum's, saves a fortune in the end and a real satisfaction of doing and solving the problem yourself.
Gwyn

[Rikos]

Really glad that you managed to get this sorted

And good to see the forum could help ... thats what we're here for!

[vinnyvangough]

Result for FOC