Mot Failure (again)

[mickyt]

hello all put my 96 n reg gal failed its mot on front offside bushes and also on the roller brake test with what looked like to be brake alignment check on front end the fail sheet states that i need new front discs and pads and also replacement bushes on what i think is the front offside wishbone

i was curious to know how the fella knew that i needed new discs and pads on front as i assumed that you needed to remove the front wheels to get an acurate idea as to whether they need replacing

i have been quoted 270 quid to do the work and i was just wondering whether the bushes could affect the cars braking system during the brake test because when i got the car home i thought i would have a look at discs and pads and the pads have around 14 mil left on all 4 and the discs looked ok with no scrathes or gouges on them there is a small lip running around the outside edge with rust on but apart from that they seem ok the bushes that he stated do however seem coroded and cracked

any ideas

thanks

[El Dingo]

Basically, the tester put your car on a 'rolling road' which tests braking force independently on each wheel.

Did you look at the inner pad, or only the outer? If the (sliding) caliper is siezed, the inner pad (driven by the caliper piston) will wear to nothing while the outer looks fine.

Is your 14mm including the metal backing plate?

[mickyt]

yes checked both out and inner a nd all roughly same size 14 mill includes backing plate

[El Dingo]

OK, so no siezed caliper, but then the pads are probably near or on the limit, especially if the discs are worn. Check the Haynes manual (if you have one?) for the recommended thicknesses, or do a search of this site? I don't remember seeing this data, but it might well be there...

 

New pads are about 13mm pad and 7mm backing plate IIRC. With 14mm this would only leave you 6mm of pad material. If the disc is worn, you risk running out of caliper... ;)

[mickyt]

i had a look in the haynes manual and in the braking sytstem section it says that the thickness of each pad must exceed 7mm including the backing plate thats why i thought it strange that i was told to replace them when they seem ok