QU80020 0.080 Brake Caliper Key

QU80020 Oversize Brake Caliper Key Kit for 1977-1991 Chevy, GMC and 1975-1993 Dodge heavy-duty 3/4 ton and 1 ton trucks with stretched Bendix type brake caliper anchor plates. QU80020 has Key in 0.080" oversize thicknesses. Use on 4x4 trucks with Dana 60 front axles and 4x2 models with heavy-duty brakes. Each Kit includes oversize key, tension spring, and QU80015 Anti-Rattle Kit. Each Kit services 1 side. Order 2 Kits per axle.

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Dan the Gear Man® Tech Notes:
Oversize Caliper Key Kits
Applications

Tech Note 1: Oversize Caliper Key Kits
It is not uncommon to find trucks with brake caliper anchor plates stretched to the point were these stock thickness keys and springs will fall out when the caliper lifts during braking. Oversize Key Kits are available to address this problem or you can replace the anchor plates. Stretched anchor plates usually are a result of grossly overloading the truck and/or towing heavy trailers with inoperative trailer brakes.

Wear occurs between the Brake Caliper, Brake Caliper Anchor Plate, and Caliper Key/Spring on Bendix type Front Disc Brakes used on 1977-1991 Chevy/GMC and 1975-1993 Dodge 4x4 trucks with Dana 60 or Dana 61 King Pin Type front drive axles. This wear causes excess clearance between the caliper and knuckle slide surface resulting in a noise condition (rattle). Continued operation with this noise can result in loss or the Caliper Retaining Spring Key which will allow the caliper to rise out of the anchor plate causing severe damage to the brakes and wheels and possibly a loss of front brakes. Vehicles that have this caliper rattle condition can be corrected by installing a new QU80000 series oversize retaining key and new style support spring. Use of the new thicker key eliminates the necessity to replace caliper and/or caliper anchor plate to provide the proper caliper thrust clearances. However, in extreme cases, it will be necessary to replace the caliper and anchor plate.

1. Measuring Procedure: After removal and cleaning of caliper, lay a straight edge across the forward caliper surfaces and measure the maximum depth of any wear on these surfaces with a feeler gauge. CALIPERS WORN TO A DEPTH OF 0.050" OR MORE MUST BE REPLACED.
2. Reinstall caliper (new or existing) back into anchor plate. Install a standard size key and retaining screw. (DO NOT INSTALL SUPPORT SPRING AT THIS TIME.)
3. Insert a screwdriver into center of gap between the key and caliper and pry firmly to seat caliper against the anchor plate.
4. Measure the gap between the key and caliper with largest gauge (or stack of gauges) that will fit into the gap for its FULL LENGTH. Select a replacement key according to the following guide: Gap between Key and Caliper is:

• 0.000"-0.060": Use QU80004 (Stock Size)
• 0.060"-0.100": Use QU80019 (0.040" oversize)
• 0.100"-0.140": Use QU80020 (0.080" oversize)
• 0.140"-0.180": Use QU80021 (0.120" oversize)
• 0.180"-0.220": Use QU80022 (0.160" oversize)
• If Gap between Key and Caliper is Over 0.220" Replace Caliper and Anchor Plate
• Install selected replacement key and new support spring. (NOTE-the support spring has been redesigned from a "C" to an "M" shape-Be sure it is installed correctly.)  Repeat this procedure for the other side of vehicle.

Applications:
Chevy/GMC:
K30, K35, K3500, V3500 1 ton 4x4 trucks: 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991

Dodge:
All W350 with Dana 60 or Dana 61 front axle: 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993
All Cummins Diesel Powered W-250: 1989, 1990, 1991, 1992, 1993