i recently purchased a a6 2.7t and need to replace the front brake caliper but all the auto stores tell me its a single piston but i actually have the dual piston . is this normal but when i look on line i can find the caliper listed under s4 thanks for the help

 

Not trying to question, but why do you need new calipers? Are the pistons leaking or something?

 

i got the car and went through the glove box found receipts for repairs and they put on the receipt recomended a new caliper and im getting some kind of vibration and was just going to start there. but the vibration stays constant as i drive . at first i thought maybe a busted belt soo i rotated the tires and still there

 

I doubt that it will be your calipers. Your rotor maybe... But it should only vibrate when you are using brakes.

FYI, calipers are pretty bullet proof.

If you are noticing vibration at all speeds, then I would start with tire and tire balancing, or wheel bearing issue. Rotating tire will not address balancing issue. It may move the vibration to another axle.

Anyways, if you think that your wheels and tires are properly balanced, then I would consider doing a visual inspection of the suspension components including all the bushing and etc.

 

will do thanks for all your help.. i did find on the driver side the upper arm ball joint had alot of play i am looking into changing both sides upper and lowers. but the noise is on the pass side but once again thanks for the help ill look into the wheel bearings thanks

 

Just another suggestion, my car too was vibrating/shaking when braking, only braking not to long ago.

Turned out the discs (front only) needed to be filed and straightened, cost 12 bucks per disc to fix.

This happens when the disc is heated and cool water suddenly hits the discs causing the surface of the disc to uneven hence causing vibrations when braking.

Filed the discs, all good now.

good luck.

 

thanks ill look into them