What Size are my Front Rotors?

[xHeart]

Thank you for covering this topic; agree, Wayne Lyng and his staff are best.
I am looking to service front brakes - rotors and pads; any thoughts on the life of calipers. It has 10yrs/160K miles.

[ggleavitt]

I'm up in PNW so not much corrosion. That being said, I've never had a need to replace a caliper in 18 years of ownership with 1 or more XC90s.

I get more or less 3 pads to a rotor (I don't turn them) with the Sport, Ocean Race gets around 2 pads to a rotor (different driver, different driving style). I use Volvo parts, easier than guessing.

[chitownV]

Thank you for covering this topic; agree, Wayne Lyng and his staff are best.
I am looking to service front brakes - rotors and pads; any thoughts on the life of calipers. It has 10yrs/160K miles.

For your specific situation, since you are in the rust belt Midwest, caliper life does get shortened due to all that winter road salt. They rust, rust can form around the piston, the piston seals dry up, etc.

What is also good to ask is when was the last time you bled the brakes and how often? Corrosion can form inside the caliper/piston. One of my rear calipers fused even though I bled them regularly. (~130k miles? IIRC)

My front caliper bleed screws snapped off from being seized. After a few years decided to replace the front calipers with rebuilt assemblies from Rockauto. This allowed me to paint clean calipers outside the vehicle so the paint could cure and harden over a couple days. This also meant I got fresh caliper carriers as the original ones started to wear grooves where the pad ears sat, which appeared could limit the pads from properly sliding as they wore down. Them XC90s are heavy, lol. At the same time, I changed to new brake hoses.

The brakes are much better now with more brake force from before while using less of the pedal. How it should be. The internal corrosion that slowly crept up was an issue.

[xHeart]

The photo above from 2019 is still fresh in my memory. Live and learn; preparing for every thing that could... here is the full saga viewtopic.php?t=91484

[abscate]

28 seconds of heat onto a bleeder will help loosen them. Limit the torque, and reheat and cool if they don’t move. Light wrist pull on an 12 inch bar. High torque will just snap them off.

[chitownV]

Unfortunately, sometimes heat, pre-treating with penetrating oil for a week, and slowly working the bleeder screws just doesn’t budge and the bleeder screw breaks.

Since all P2 XC90s are probably high mileage by now, it sometimes makes sense to just get a new set of rebuilt calipers and brackets, plus add replacing the brake hoses. It’s also a great time to upgrade the brakes to larger 336mm if yours are smaller. The rebuilt calipers are now affordable and with new brackets, there shouldn’t be a groove worn from the brake pad ears.