JasonS

iTrader: (62)

When I get in my GSL-SE 1st off in the morning and press the brake there is a fairly loud pop that comes from the front brakes. Any ideas? After the 1st pop I don't hear it anymore. Either that, or it's not as loud.

LongDuck

Sticking caliper.

This happens when the caliper pivots aren't lubricated properly which allows them to build up dirt, corrosion, or rust on the rods that hold the caliper in position on the mount. When you push the brakes in the morning, it causes the 'pop' because your pedal pressure forces the piston to compress the pads against the rotor and pops the caliper even on it's mounts. Our cars (all Gen1's) have 'floating calipers' that allow the calipers to slide back and forth on 2 pins to center the pads against the rotor and decrease rolling resistance when the brakes aren't in use. Very common braking design and very reliable as long as they're well-maintained.

Fix this by removing wheel, removing 1x14mm bolt at BOTTOM of caliper (either side), and then rotating caliper up on the upper pivot bolt. The lower bolt needs to be lubricated by squirting good grease into the rubber boot at the bottom of the caliper, and the upper pivot bolt is lubricated by removing the caliper completely from the pivot (hydraulic line stays attached), and then lubricating the bolt before you slide the rubber boot at the top of the caliper back into place. Reassemble, be sure to torque lugnuts to spec (70-80 ft/lbs - I prefer 90 - just keep them even).

If you do this right, it's a 15-20 minute job. Do both sides, since it could be one or the other. Chances are if you do the one you think is making the noise, it's gonna be the OTHER one that's actually causing the problem!

Poorly lubricated caliper bolts will cause uneven pad wear, strange noises (like you described), and squealing and such. For the effort, anytime you have the calipers open, lube the pivots just for good measure. Don't put so much on them that the grease can get on the rotors, however. HTH,