Brake Diagnostic suggestions

[floating_weasel]

Hi folks,

Having an issue with serious steering wheel shudder on moderate to hard breaking.
No real loss in braking power, and doesn't seem to be an alignment issue as car drives
true at all speeds. No strange noises or squealing. Had rotors refaced a while back, but
this developed recently.

Thoughts ? Is it time to replace pads perhaps ? I really don't have any ideas as I am not
a gearhead and can only report what I feel.

Thanks muchos everyone.

[floating_weasel]

Oh and if you think it is time to swap out rotors and pads, any suggestions on slotted/drilled ones+pads that offer great value and stopping power for daily driving and where to get them would be a super help.
(I know, I know, overkill for daily driving, but they look so darned sexy and I actually did splurge on rims that allow you to see a great deal of the braking mechanisms)

[stevenma188]

Just get Centric or OEM blanks and good pads (Hawk or Stoptech). X-Drilled rotors will decrease performance, and good slotted rotors = $$$$

[Wes08M3]

If the technician did not do a thorough job machining the rotors, the condition you described can result. Also, if he machined them and there was not a sufficient amount of useable material left on the rotors, it can also cause shudder.

Certain less trustworthy technicians will recommend machining the rotors instead of replacing them because they get paid more in labour to machine them. However, these days, in most cases it is more economical for customers to just have the rotors replaced.

I agree with stevenma on the OEM rotors if you want something good. If you want really good performance (i.e., track performance) you'll have to pay big bucks for slotted/drilled rotors for sure. Those cheap(er) slotted/drilled rotors are not worth the money. Hawk or Stoptech pads are a nice performance pad as well but if all you're doing is daily driving, you probably wouldn't notice much difference over OEM pads.

[highlineMotors]

Hi folks,

Having an issue with serious steering wheel shudder on moderate to hard breaking.
No real loss in braking power, and doesn't seem to be an alignment issue as car drives
true at all speeds. No strange noises or squealing. Had rotors refaced a while back, but
this developed recently.

Thoughts ? Is it time to replace pads perhaps ? I really don't have any ideas as I am not
a gearhead and can only report what I feel.

Thanks muchos everyone.

Sounds like warped rotors to me.

[krimsalt]

Sounds like warped rotors to me.

Super +1

[Flagrum_3]

If the technician did not do a thorough job machining the rotors, the condition you described can result. Also, if he machined them and there was not a sufficient amount of useable material left on the rotors, it can also cause shudder. Certain less trustworthy technicians will recommend machining the rotors instead of replacing them because they get paid more in labour to machine them. However, these days, in most cases it is more economical for customers to just have the rotors replaced.

I agree with stevenma on the OEM rotors if you want something good. If you want really good performance (i.e., track performance) you'll have to pay big bucks for slotted/drilled rotors for sure. Those cheap(er) slotted/drilled rotors are not worth the money. Hawk or Stoptech pads are a nice performance pad as well but if all you're doing is daily driving, you probably wouldn't notice much difference over OEM pads.

+1 to the whole comment, but even if the tech had surfaced the rotors to the 'proper' minimum thickness, this still leaves the rotors pretty thin, causing excessively fast heat build-up, which will cause warping, which I'm pretty sure thats what the OP is experiencing. As for replacement rotors/ pads; Message JR AUTO Concepts, one of our sponsors. They have a pretty decent brake package and for a very decent price...I'm happy with mine so far.

_3

[Wes08M3]

^^ agreed. I'm not a fan of machining rotors, I'd rather buy the chinese rotors before I bothered to machine an old set.

[floating_weasel]

Ok, update on where I am at the moment. Inspired by you guys and armed with youtube knowledge and a Haynes manual I would very much like to try a brake job, front and back. I am not under the illusion
that I am any sort of a professional mechanic, but genuinely want to learn how to do as much servicing of my car on my own as I can because I really enjoy it. I am off to Princess Auto to pick up a few specialty tools
(have a gift certificate from Xmas I want to use up. Is it true that the rear brakes of the Mazda 3 have to have the brake piston rotated as it is pushed in for it to retract properly ??) I have picked up Stoptech drilled rotors and Akebono pads for the front and back (they seemed a good price, not cheap, not super pricey). I hope this is this within acceptable norms. As for my regular mechanic, it is a place called Motortech in Concorde. Two old Italian guys run it (Gabe and Tony) and they are old school honest to the bone. I love em to death and am not sure where I will head when they eventually sell as they always do the right thing. The only reason he machined the rotors is because he didn't want to have to replace them and he didn't even charge me. Any little tips you want to throw out before I get crazy ? (don't worry safety first and jack stands are already taken care of) As for JR AUTO Concepts, sorry I didn't buy there, went on a visa rampage before I read that post. Thanks though

[Wes08M3]

Yes you need to push and rotate the piston on the rear calipers to compress it. You can rent the kit from partsource for free (deposit is required, however). Just ask for the rear brake caliper tool kit, they'll know what you mean. Or you can buy a tool for it (~$15), it's a cube looking thing, doesn't work too well in my opinion.

If you have air tools, specifically a die grinder, it's a good idea to buff the hub to remove any rust before you put the new rotor on. If you don't have air tools you can use sand paper to get as much rust off as possible. You should also put anti-seize on the shoulder of the hub (where the rotor and wheel rest on the hub). But don't put too much, just a nice thin layer.

Make sure to also clean the carrier with a wire brush, specifically where the brake pads are seated on the carrier. Don't forget to get caliper lube! You need to lube the slider pins (be sure the sliders are clean and smooth before you lube them), the rear face of the brake pads where the caliper will contact them, and lube the carrier where the pads will be seated.

A brake job isn't all that hard but many people neglect these small steps which can result in break squeal and/or premature wear.

Good luck!

[floating_weasel]

Worked up my courage and did the front brakes today. New stoptech rotors and Akebono pads. It was surprisingly easy aside from my pitch black hands when I was done. When I went out for a test drive the horrible shuddering steering wheel issue when I braked with the old parts was completely gone ! Woohoo !

The old pads had tons of life still left in them so I guess the issue was with warped rotors. They weren't too thin as I measured them with a micrometer, but it could be that they were knocked a bit out of true when my mechanic had to get them off last year. (They were so seized with rust that it took him a long time with a hammer and other tools on the back to get them off the hubs. He machined them afterwards but maybe it was just time for them to go)

Anyway, thanks everyone for all your help, no way I would have tried this without all the advice but it turned out great.

Question: The brakes felt a tiny bit soft at first, but then I realized that I hadn't re-tightened the brake fluid reservoir. After I did that they felt much better. Would that make that much of a difference ? Also, how hard is it to bleed your brakes ? I have a bleeding kit and a lot of dot 3 recommended fluid and I figure once I do the backs I should probably flush the system so that everything is fresh from scratch. Never done it before thoughts ?

Also, what should I try to do next ? I'm feeling great about taking control of maintenance and simple jobs. Transmission fluid change ? I'm overdue.

Thanks again.

[highlineMotors]

(They were so seized with rust that it took him a long time with a hammer and other tools on the back to get them off the hubs. He machined them afterwards but maybe it was just time for them to go)


Mazda's are common for seized rotors. I don't think they use anti-seize when they install it at the factory. Sometimes you even have to use a torch. And what kind of mechanic machines a rotor after bashing it with a hammer? :bang

[Wes08M3]

Bleeding brakes is rather easy. Be sure to start with the passengers side rear wheel, then move to the drivers rear, then passenger front, then driver front. if you drove a bit with the cap loose it would be a good idea to bleed them as a bit of air may have got into the lines.

Transmission fluid change is also very easy. Good DIY project.

Nice work so far!

[bmxnwrx]

not many places machine rotors anymore. just buy new. good pads and OEM quality or higher rotors and your set.

[floating_weasel]

Did rear brakes today. Very problematic. Strange problem surfaced on each side. The bottom mounting slider pin on each caliper was jammed in (dry as a bone) and it took a lot of wrestling to get it out to remove the pin (top pin was fine). I got it out but when I put on new rotors and pads and tried to put the pin back in to attach the caliper it wouldn't fit through unless I jammed it through with some channel lock pliers. It was like the rubber bushing was warped somehow and the slider pin wouldn''t fit through anymore. I ended up drilling out the bushing with a 1/2 inch drill bit to remove the bunched up rubber as a very short term solution as I couldn't figure out what else I could do. I mean I tried to do it without the adjustment but then the top pin slid back and forth perfectly and the bottom pin was sort of seized and wouldn't move properly (both were properly lubed). I knew that would result in uneven crappy wear on the pads so I came up with the drilling idea. Can anybody tell me how to fix this properly ? Can you buy new rubber bushings for the calipers ? If you can any tips on installing them ? I hate doing a Macgyver job even if it will work in the short term. (Or perhaps it will be fine but I have no idea)

[Wes08M3]

Not 100% sure about the Mazda 3 specifically because I've never had to change the boots on one, but generally you can get a boot kit for the calipers. That way you can pull the old one off and try and clean the crap out of the pin bore on the caliper. A small wire brush (preferably one attached to a die grinder) should help clean it up. If not, a cylindrical file might do the trick.

But to be honest, if the boot isn't damaged and your drilling method was successful in allowing the caliper to slide freely, I wouldn't be too worried about it. If its sliding freely then it's doing what it's supposed to do. In reality the sliders usually don't take very long before they start to seize up again which is why you're supposed to service them yearly.

[floating_weasel]

Okey dokey Wes, thanks for the advice. The boot isn't really damaged at all, and my drilling was pretty delicate. I think what may have happened is that the pin was in there so tight that when I pulled it out
it pulled the rubber along with it making a bit of a lip on the inside. It's very hard to describe but sort of like having a sock bunch up on your foot instead of being one smooth uniform thickness in your shoe.

My final issue is that my parking break is pretty loose. It was loose before but now it is really loose. Any tips on how to fix that darling ? I haven't dug in the forums yet because I have gotten lazy with you dispensing instant great advice all the time. ;)

Oh, and I'm not sure but I think brake cleaner melts asphalt. Can I get a verdict on that ? I definitely have some strange looking spots on my driveway after the excess from my spraying hit it.