Vibrations while braking

[crazyfingers]

Car info - Gen 3 94 camry V6 XLE with ABS (four wheel disc brakes =])

i experience a lot of vibrations while braking from pretty high speeds
now let me tell you, i replaced the brake calipers and pads a few months ago
i replaced the front rotors like a month ago
and i replaced the rear brake pads a few weeks ago

and i still get these vibrations

should i also replace my rear rotors?

i should also say that when my mechanic inspected my brakes ( a few days before i replaced the rear brake pads)
he said that the rotors dont need to be replaced
should i believe him?

[Kep]

Were the replaced front rotors brand new or were they used & turned?

When you expanded the caliper cylinders for the new pads did you force the brake fluid back into the system (bad) or did you allow it to flow out of the bleeder valve (good)?

When the mechanic said your back rotors were OK, did he use a gauge or did he just eyeball them? It is pretty easy to tell if they are worn down too far but difficult to see if they are warped without a gauge. If you do have someone gauge them, have them do all four.

Was it pulsating prior to you doing this other brake service?

I've never had ABS brakes. I have heard that there is generally a way to disable them and that when you disable them they revert back to "standard" braking. If this is possible, then disable the ABS and see if it goes away. If it does then it's the ABS system. If not then it's the brakes themselves. Maybe someone here will know for certain if and how you can do this.

Kep

[Venom_5]

rotors definitely need to be resurfaced .... idk why it happened so fast, but vibrations under braking at high speeds is a dead indication that they are warped or uneven

[crazyfingers]

the rotors i bought were remanufactured ones (well they were new but all new car parts are pretty much remanufactured) from pepboys
and i think he just eyeballed the rear rotors when he said they were fine

and about the calipers, im not sure what you mean by forceing the brake fluid back into the system but i think i did it the second way (me and my dad did it) we allowed the fluid to bleed somewhat

and yea it was vibrating before doing all this brake service

[Kep]

When you replace the brake pads you need to force the pistons back into the brake cylinder and the brake fluid has to go somewhere. In older cars you could just press on the pistons and let the fluid go back into the brake fluid reservoir with no problem (you sometimes had to empty the reservoir to keep it from overflowing). In cars with ABS you are not supposed to force the fluid back into the ABS gizmo so you typically put a hose on the bleed valve and put the other end in a container. You open the valve and then put pressure on the pistons to open them. Now the fluid flows out the tube right there at the brake cylinder rather than going back into the ABS system. If fluid was draining out at the brake you were working on you probably did it right.

Remanufactured rotors might warp sooner. I've never heard of remanufactured rotors. However, if it was happening before you did the work and before you put on the remanned rotors then they aren't likely to be the problem.

I'd have the rear rotors looked at closer. Call around and see who can check them for you.

Kep

[Black95Cam]

it could also be from the an unblanced tire(s) or any suspension part.

[crazyfingers]

it probably isnt unbalanced tires since i just got a tune up and they balanced all my tires

[SwampFox]

Check for over torqued wheel lug nuts which can warp the rotors at the area of threaded studs on the wheel hubs. Over torqued is very common when the nuts are put on with an air impact driver, pneumatic air gun. I believe the nuts should be torqued to 76 ft.lbs. with torque wrench. Check your car owners manual for proper torque. The best would be to remove the wheel and rotate about a half turn and then mount the wheel to the wheel hub and torque.