Perfect replacement for 2004 Mercedes ML 350. Inspect and replace when you replace the brake disc or install a new caliper or every 5 years. Damaged anthers will not retain caliper pin lubricant, causing the caliper to stick to the pins and causing normal pad and rotor wear. Improve braking performance and extend the life of your brake pads and brake discs. Only use silicone grease in these caliper boots. Super Lube 92003 PTFE silicone grease, 3 oz tube, translucent white, excellent for adjusting and lubricating caliper bolts and pins.