Just read an ad for resurfaced disks and new pads for about half the price of new disks & pads.
What are the pros and cons ?
Sorry, pros are obvious, half price. What are the cons ?
|
Well,
Resurfaced means ground on a machine so that the peaks and troughs are removed.
This also removes much of the metal as both sides of the disc face are finished.
Often, this results in a disc that is half the thickness of a new one, and costs unsurprisingly, half the price of a new one but lasts MUCH less than a new one as you have to change it before minimum thickness.
I suppose you're American, with your spelling of "disc", so we'll use dollars. If you're not, consider yourself reprimanded. In the UK "disk" is an abbreviation of "diskette", a PC floppy.
I can get a new, vented, disc for my Golf for £23. It is 22mm thick and should be changed at 12mm thick. Therefore, the 40,000 miles it lasts before wearing out means about 1mm per £2.30
If i bought a ground disc it would be about 17mm thick, if I were lucky. To get to 12mm is only 5mm away, so I'd be lucky to get 20,000 miles out of it.
If it cost more than £11.50 I've lost money. Then I have to change it again, twice as often as if I bought a new one in the first place.
Plus, thinner discs are much more prone to warping, so it may die early.
Then, how did it come to be for sale? Did the first owner write the car off, and bend the disc?
No mate, with braking, you'd be daft to use secondhand, reworked parts, especially when new ones are so cheap.
|
I have to agree with Sean on this one.
Why bother to take the chance with secondhand goods like this. I once had a brake disc shatter on a Ford Orion and it scared the life out of me. It certainly taught me how important the brakes were and how important it is to look after them.
Don't risk it.
|
Additionaly if there is less metal there, there is less mass to disipate heat. As a result you will have inferior braking. The disc may also have been damaged from overheating.
|
If a remember rightly when Cortina were still being used and abused as rep mobiles in the early eighties when you overheated the brakes for the first time you quite often gained a braking vibration. On replacing disks all was well untill you next overheated the brakes (very easy to do).
If you had the new and warped disks skimmed instead of being replaced then they didnt warp thereafter. Seemed as if the first warping somehow heat treated the disk.
|
On the other topic on disks shattering (as discussed above) this used to be commonish on Fords with fixed twin piston calipers.
If one caliper piston seized (common!) then the brakes only applied force via one pad, flexing the disk in the process. Eventually after many operations in this mode the disk fractures due to metal fatigue.
|
|
|
