It’s been a long time since my last post here, mainly because our 2WD XC60 has been very reliable. After 72K mostly highway miles, it began making intermittent scraping noises from the right front during and briefly after braking. It sounded like a pebble got in there, then would go away. I started exploring on Swedespeed and elsewhere like YouTube for how to replace the front pads. Some common themes emerged:
A. The inner pads wear more, so when you look at the caliper through the wheel, the outer pad has deceptively plenty of material left, ¼” in our case. I think that is because any drag in the slides or rails will impede application of the outer pad, favoring the inner one. That seems to be a fact of life with floating calipers.
B. The passenger (right) side wears more. That may be because of how the stability control works the brakes.
C. Volvo DOES NOT USE WEAR INDICATORS! Is that a plot to sell more rotors or what?
D. Many of these instructions leave out torque specs or important steps, even those that Volvo mechanics use (which the parts guy copied for me), like how to properly compress the pistons.
E. I really miss having a physical book like a Haynes manual. Is there anything like that available yet for 2015 models?
So I decided to write a complete DIY procedure, sans lift, one front wheel at a time, assuming that the rotors are still OK (no bad grooves or pulsing).
*= see photo.
1. Put on neoprene gloves, then chock one rear wheel.
2. Apply the ebrake, then shift into Neutral, then shut the engine off.
NOTE: It may tell you to put it in park, but after a few tries, will shut off the engine. You will need it in Neutral so you can turn the rotor. If you jack up both sides at once, you don't need to put it in Neutral. [TNX to RyanR] When you turn one rotor, the opposite side will turn in the opposite direction, which may take more effort to overcome the drag of both sides.
3. Use a sturdy floor jack under a front jacking point and lift it about an inch.
4. Loosen the 5 lug bolts slightly using a breaker bar and 19mm socket.
5. Continue jacking until the tire is ~1/2” clear of the floor.
6. Place a jackstand for safety under another front jacking point.
7. Undo the lug bolts completely.
NOTE: Even a light duty impact wrench makes this easy.
8. Remove the wheel and check the tire, then put something like a tray or pizza pan underneath to collect debris*.
9. Using a screwdriver, remove the anti-rattle spring from the outside of the caliper.
10. Inboard of the caliper, remove the plastic caps from the upper & lower slide pins.
11. Unscrew the slide pins using a 9mm Allen bit.
NOTE: This odd size, left out of most Allen kits and not close to any SAE size, is available, e.g. from AutoZone. It is apparently becoming common for brakes by other manufacturers as well.
12. Compress the brake pistons just enough to slide the caliper out.
13. Unplug the brake hose from the holder (welded to the strut)*.
14. Pull out the caliper, then rest it on top of the backing plate* and pull out the old pads.
15. Using brake cleaner spray and a non-metallic brush that won’t harm the boots that protect the pistons, clean up the caliper.
16. Remove the rubber cap from the bleed screw.
NOTE: Many procedures omit these steps and just have you push old brake fluid back up into the master cylinder, but that has been known to cause corrosion problems there and in expensive ABS units. If your brake fluid needs to be changed anyhow, these steps are not necessary. [TNX to Tech]
17. Put a 11mm combination wrench on the bleed screw*.
18. Add a clear hose* to the bleed screw that leads into a bottle* to collect waste brake fluid. Keep it off any painted surfaces.
19. Position a brake piston compressor tool with a wooden block so it pushes on both pistons*.
NOTE: You can do it one at a time, but sometimes pushing in one piston pops out the other.
20. Open the bleed screw very slightly, then compress the pistons fully, collecting the waste fluid.
21. Tighten the bleed screw and replace its cap.
22. Using a file and steel brush, clean up the outer edge of the rotor as you turn it, and clean the slides in the caliper bracket.
23. Using coarse emery cloth, go over both rotor surfaces as you turn it.
24. Clean everything with brake cleaner spray, making sure that no debris is stuck between the rotor and stationary surfaces.
25. Clean the slide pins using a wire wheel.
26. Using a brake lube like SilGlyde, grease the sliding edges of the pads and corresponding slides in the bracket.
NOTE: This is important to enable the caliper to float freely, but don’t get any grease on the pads or rotor.
27. Plug the inner pad into the pistons, taking care not to damage the boots.
28. Put the outer pad in place and slide the caliper into the bracket.
29. Screw the slide pins in and torque to 60 Nm.
NOTE: The Volvo book says not to lube the slide pins. They slide in non-metallic bushings that are designed to help pull the pads away when not braking. Caliper hardware kits with new anti-rattle springs and slide pin bushings are also available [TNX to RyanR].
30. Plug in the plastic slide pin caps and the brake hose to it’s holder welded to the strut.
31. Install the anti-rattle spring.
32. Pump the brakes, which should firm up after 1 or 2 strokes, then check that the pads are firmly in place, but the rotor can turn freely.
33. Using silicone spray, spray the brake hoses, CV boots, rack boot, ball joint and tie rod boots, and anything rubber to resist dirt and help preserve them.
34. Put the wheel back and torque to 103 Ft-Lbf.
NOTE: I made an installation aid that screws into one of the lug bolt holes.*
35. Remove jack stand, chocks, and jack.
36. Test drive.
37. Repeat for the other side.
38. Clean up and note in your service log.
I will probably do the rears soon and will write that up as well. It is complicated by the electric parking brake. While the car was getting some warranty work done, the rear pads were replaced at just ~35K miles “because of the stability control using them a lot”, according to the dealer. Volvo always replaces rotors along with pads, so that was very expensive and not covered by warranty.