braking and vibration

[JT_MONEY_2004]

I took my '90 into Meinekee(sp) last week to have my brake and suspension components inspected (Free). Tech tells me everything is in good condition. Brakes 50%+, calipers working, rotors ok but will need replacing w/ in a yr, shocks good etc. ok the only problem i know i have are worn, old tires (soon to be replaced) I do get a bumpy ride at slow and high speeds--think i have an old tire our of round, BUT i also i get a vibration when i brake hard at 60+ mph. if my brakes system is ok, then what else could be the cause...should i take it in for another inspection somewhere else??

[elwesso]

Warped rotors... The rotors are OK (as in they work right, i mean its ahunk of metal, what is there to fail), but they are still warped... I guarntee they didnt measure the runout on the rotors.....

I lived with warped rotors on my old Q...

[AZhitman]

Yep - Wes nailed it.

Get the rotors turned and you'll lose the vibration (most of it anyway).

[Q45tech]

Truing the rotors off the hubs on an external lathe means they will feel warped again within 5,000-6,000 miles. Precision expensive runout correction is necessary to extend the interval.

[JT_MONEY_2004]

I remember reading a post where someone described a machine that uses a "pin" on the tip of it to measure the rotor's roundness/smoothness-- i asked the guy is he used that test, said NO he used something that was computerized but basically the same test...BS??

Which set of rotors are likely to be the culprits f/r? Which should i replace first since i probably wont be able to do all 4 at once -- or should i have them checked on specifically?

p.s. Wes i recieved your package, Thank You. Not only does it look better than before, BUT, i got my one of my favorite features back*** sunroof *** is now fully operational, i guess switch was bad.

[louiegz]

Which set of rotors are likely to be the culprits f/r? Which should i replace first since i probably wont be able to do all 4 at once -- or should i have them checked on specifically?

I had the same problem when the Q was new. The front ones were warped. I got them tured when the pads had to be changed. Just get the rotors tured when you get your brakes done in the future. I've been told that you should be able to get 3 resurfaces done on OEM rotors. If your past the third one, then get new rotors. How many times have your rotors been turned?

[elwesso]

p.s. Wes i recieved your package, Thank You. Not only does it look better than before, BUT, i got my one of my favorite features back*** sunroof *** is now fully operational, i guess switch was bad.

JT... Sorry i was such a PITA to get a hold of.. hopefully i got my email issues worked out!

[JT_MONEY_2004]

Unfortunately i dont know how many times they've been re-surfaced or even if they're OEM. Bought this car earlier this yr, i do know per meinekee that theyr's not a whole helluva lotta meat left on 'em. i dont know if they can be turned again. Will have then checked on again soon. --My last Q was smooth at 100mph, this one is a basket because of vibrations at 85mph. Who makes a decent (bang for the buck) replacement rotor?? beside NISSAN

[JT_MONEY_2004]

Can a novice weekend-er w/ basic tools and and only one pair of hands replace Q rotors??

[maxnix]

Unfortunately i dont know how many times they've been re-surfaced or even if they're OEM.... Who makes a decent (bang for the buck) replacement rotor?? beside NISSAN

Try measuring the rotor thickness with a micrometer at several different points. If the rotors are of sufficient thicknes, use a dial gauge to measure variance. Then find a very good machine shop to turn them (or the new ones for that matter). OEM, Stillen Brembos, Powerstop are the best bang for the buck unless you love frequent brake work.

Aren't you near T-3?

[JT_MONEY_2004]

Yeah i plan to call 'em to get a quote for replacement if necessary. I wouldn't want to go that for just for an inspection tho'. Ideally i'd like to do 'em myself if there isn't much room for error. You fellaz have helped me do several different projects since i got car.

Goldmine of DIY info = NICO

[squeefoo]

The rotors come off once you've got the calipers off. Just need metric wrenches. Make sure you clean up the hub nice, and put anti-seize, or heat sink compound on once they're clean. You can do it yourself.