Brake discs at the same time as new pads?

[Deacon 1357]

I've never bothered changing brakes on a car before but would like to on the 86.

I have the pads I want to use but should I also be changing the discs for new ones and would something like the pagid discs that eurocarparts sell be suitable (i.e. if not an upgrade then no worse than stock?) 

[long-gone 152]

My first set of rotors were spent at about 25,000 miles, replaced at same time as pads.

Replaced with Brembo rotors and EBC GreenStuff pads and at 50,000 miles they're less than 50% worn. Stops pretty well too, and no squealing like originals.

[Mike 458]

Some people will say you should change discs if you're changing to different pads (ie not replacing with the same pad) as you'll end up with 2 different pad materials on the disc which can't be the ideal situation.

When I went from dixcel to yellow stuff I didn't change discs and they're perfectly fine although I wasn't convinced by them at Woodbridge but that could have been because they were new (or down to the above...)

How worn are the discs? If you're likely to replace them before the pads are done, I'd replace them now.

[Deacon 1357]

4 minutes ago, Mike said:

How worn are the discs? If you're likely to replace them before the pads are done, I'd replace them now.

Not very to be honest - couple of mm maybe? I don't really brake much...  😁

[Mike 458]

I'd keep the same discs on then unless you want to upgrade...

[Kodename47 446]

27 minutes ago, Mike said:

unless you want to upgrade...

Upgrade discs?? Blanks/Slotted/Drilled.... all much the same  (unless you go bigger/2 piece of course)

[Ade 517]

@Deacon get a micrometer and measure the thickness of the discs. min is 22mm.

If they still have plenty of life then dont worry about changing the discs, just makes sure the pads sit flush and not on any ridges created by wear. 

[Deacon 1357]

23 minutes ago, knightryder said:

Upgrade discs?? Blanks/Slotted/Drilled.... all much the same  (unless you go bigger/2 piece of course)

If I do change the discs is there any advantage in replacing them with something else (like an ebc disc) or would a oem replacement set do just as good a job? 

[Keethos 842]

I changed just my pads to the Stoptech pads and I wasn't always overly confident with them, as you might remember, I've mentioned before that they sometimes stopped very well but then other times it would feel like it didn't want to stop at all.  When I think about it, my discs had a slight lip to the edge so I've always wondered if that lip of the disc contributed to this feeling.

[Church 209]

If you use them with oem calipers .. maybe you can consider 2 piece ones (hmm, DBA?), for slight weight savings and a bit better heat conducting. Unfortunately here in LV rules are much stricter. No aftermarket BBKs, if stock one piece, then no two piece disks, steel armored brake lines need to be nylon covered on outside aswell, and pressed in, not boltable on to stay road legal. So i guess that only thing that i can upgrade are pads/fluid and add brake ducts, rest staying OEM :(. I guess, MOT rules are more laxed in UK, no? Well, whichever disks you go with, i highly advise to NOT go for drilled/slotted. You get all needed more brake bite with higher mu brake pads. No need to compromise disk strength, even more so if used also on track, with fancy showroom only worthy drilling.

[Ade 517]

46 minutes ago, Keethos said:

I changed just my pads to the Stoptech pads and I wasn't always overly confident with them, as you might remember, I've mentioned before that they sometimes stopped very well but then other times it would feel like it didn't want to stop at all.  When I think about it, my discs had a slight lip to the edge so I've always wondered if that lip of the disc contributed to this feeling.

If your discs have a lip make sure the pads arnt sitting on the that lip otherwise the pads will sit on the lip withminimal contact area and generate hot spots and essentially pad fade.

Ask me how I know...... I'll tell you anyway  my AP racing discs had a lip I failed to notice and the pads didnt sit properly. So when things got hot the pedal would travel quite far before on the threshold of lockup. I took them out and filed down the edge so the pad sits nice and flat on the face of the disc and the brakes were so good after that. 

[Keethos 842]

Sounds about right, luckily they were on my old stock fronts and I'm sure the rears have bedded in by now.

[Church 209]

BTW, about 'brake discs at the same time as new pads' .. how many pads you've been through? Shouldn't disks on average last some 4-5 sets of pads? Are stock discs really worn down or cracked enough to warrant purchase/exchange?

[Deacon 1357]

My brake pads are about 10% worn after 3 and a quarter years (I said I don't brake much!) Discs are fine. The question related more to what @Mike mentioned about the issues with different pad material on the same discs. 

[Ade 517]

16 minutes ago, Deacon said:

My brake pads are about 10% worn after 3 and a quarter years (I said I don't brake much!) Discs are fine. The question related more to what @Mike mentioned about the issues with different pad material on the same discs. 

itll just take a little longer to bed them in.

I went from stock -> ds 2500 -> Mu HC800+ -> Mu Club Racers without issue. Discs were down to 22.5mm after that lot.

[Church 209]

Funny, but DS2500 for me are quieter then stock. Without any bedding, right away. Though I didn't notice much increase in brake bite either. i guess they might be closer to street pads then some others interim/hybrid street/track pads. Well, stockers were close to done and to exchange for new ones anyway.

[Lauren 2259]

It's not necessary to change your discs providing they are fine when changing brake pads. I've found that pad and disc life is about the same at around 37K miles or so. But it's totally not necessary to change your discs at the same time.