Hi guys!

I know several of you have quite a few trucks including later model rigs. Saw this message posted on Diesel Truck Resource Forum and wanted to pass on the warning, just in case it applies to one of your trucks.


[www.dieseltruckresource.com]


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 thust clearances. However, in extreme cases, it will be necessary to replace the caliper and anchor plate.

Measuring Procedure:
1. 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 .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. CLICK HERE FOR IMAGE!
5. 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!
6. 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.)
7. Repeat this procedure for the other side of vehicle.