Pads/rotors

Bingo. My rotors are no longer pristine at 142k miles, but I've no intention of replacing them when I do pads this summer.

Since they stopped using asbestos in the friction material used in brake pads, the pads are now normally 'harder' than the cast iron discs (rotors) themselves so disc wear is much more common than it used to be. This is particularly evident in smaller cars over here in the UK where the discs are relatively thin to keep the weight down. The later model Ford Fiestas (a small hatchback) are well known for consuming a set of discs for every 2 sets of pads.

My 70K miles Eunos had new discs at the front a year or so before I bought it in November last year. The rear discs are a bit scored, so I'll probably replace them (and the pads) before the next MoT test (annual safety check).

Ask the dealer whether he's measured the thickness of the discs and whether they are thinner than the manufacturer's tolerances.

Replacement discs are fairly cheap if you get pattern ones (probably made in the same factory as the Mazda originals).

Same here, and I have 105K on my rotors. As long as they don't get scored up and don't warp from massive over-torquing, they last quite a while with OEM pads.

If there was going to be a performance increase from replacing them I would do it, but they work fine.

It is that 18 year old master cylinder that is starting to worry me, though it is also working great right now. The car has had very regular brake fluid changes since new, so that probably has helped.

Pat

Maybe, maybe not. Rotors that are scored can be turned but only until a minimum thickness is reached. If you haven't the tools/knowledge to do it yourself get a second opinion, it might save you a bunch of money!

Miker, YES, I believe you're being ripped off. It's that simple. If they really checked the thickness of the rotors, they should have it written down in your file. Have them quote you the mfr's min thickness and your current thickness. They will start crawfishing like a son of a you know what. 'Rotors and pads' just sounds so ......... right. Most people don't know any better and the dealer cleans up. If you confirm our suspicions are right, don't go back any more and I recommend you cause them some serious grief!

Chris

XS11 - I've done it all on various Yamaha's, just wondered if there was something different about the Miata's rotors. Mine have no scoring and are in identical condition to the rears, which the dealer rated green. He's rated my front brakes as yellow the last couple oil changes so I think that's just pad life.

Anyone have the thickness spec for the '96 front rotors to hand? I might as well check it.

miker

No, they're all similar.

They're probably OK, then.

I don't know but it's marked on most rotors. You may have to remove the rotor to see it.

I have actually never had a rotor turned, going on 20 years of brake service now. I am careful about replacing pads in time since the first time I heard that metal grinding my van to a stop at age 17.

With the cars that I have worked on with scored rotors, I have always just replaced them, the rotors that is. ;-)

Disc brake work is probably the easiest and highest-profit work that can be done on a used car. It amazes me what they charge just to put new pads on. One bolt, flip that caliper up and secure it, replace the pads, drop it back down and tighten the bolt, making sure to grease it first.

If he can remove the rotors on his car, he can also do your his pads and rotors, at least on the front. The rear calipers that adjust for the e-brake are a little more work, but it is still a very easy job.

Of course, he might not want to do it himself, which I can also understand very well. Nothing much more frustrating sometimes for me than working on cars and computers.

Pat

...and at this point you hear a "thunk" as the edges of the pads hit the edge of the rotor, possibly damaging the new pads.

Not to mention the fact that you didn't even check the seals while you were in there.

If I maintained my FF like that, I'd probably be dead now. 8;)

-- Larry (picky, picky...)

If you really want to be picky, you should also mention checking the brake fluid level to make sure it doesn't run out of the master cylinder while spreading the caliper pistons to make room for the new pads to fit over the rotors.

I actually check for brake fluid seepage at the caliper seals every time I replace the brake fluid and grease the slider pins, which is much more often than the pads get serviced. Still, I should have mentioned it since it also gets done at pad changes.

Another thing that I do is check to make sure that my stainless brake lines are secure after Lanny got me all paranoid about them coming loose. ;-)

What is your FF?

Back to my late-night spark plugs and air filter maintenance......

Pat

That was exactly what I was getting at. I think a piston/pad spreader (an "X" of aluminum, about nine inches long, with a hand-turned bolt for spreading) may be the most worthwhile single purpose tool I've ever owned.

Yup -- good advice for the OP.

'72 Elden Mk 10, 75 Lola 342C. Was, actually -- gone now, in preparation for retirement. 8;(

-- Larry

Good idea, I'll have to make one of those. On bikes I've always been able to just put a chunk of aluminum over the piston and squeeze it in by hand, I assume cars are harder.

miker

Remember that on the rear, you'll need to back off the adjuster first.