BENDIX TCH-020-018 manual Technical Bulletin, “Hard Boot” vs. “Soft Boot” Identification

Technical Bulletin

Bulletin No: TCH-020-018 Effective Date: 10-1-2009 Cancels: N/A Page: 1 of 1

Subject: Changes to Bendix® 55250 Caliper Core Classifications

Effective January 1, 2010 Bendix Spicer Foundation Brake LLC will no longer accept the Pre-1989 “soft boot” style caliper cores, piece number 55250, into core group number 22. These calipers will be accepted under core group 69 only.

The old “soft boot” style calipers are of a design superseded in 1989 by the improved “hard boot” style. Although the caliper assemblies can be used interchangeably, the component designs are not the same. Caliper machining differences do not allow interchangeability of maintenance kits, components, and therefore cores.

The “soft boot” and “hard boot” calipers can be identified by appearance or by depressing the edge of the boot with a screwdriver as shown in the illustrations below. The “hard boot” style has a hard metal surface in the boot near the caliper bore. The “soft boot” style can be identified by the 3-fold boot design and by the lack of the metal reinforcement near the caliper bore. Casting numbers or other markings can not be used as an identification method.

For additional information regarding core classification and values, see Part Number Update Bulletin PNU-146-000.

“HARD BOOT” “SOFT BOOT”

Reinforcement

“Hard Boot” vs. “Soft Boot”

Identification

		Piston		Piston
Metal Insert
Heat Shield		Caliper	Heat Shield
				Caliper
Boot -
			Boot -
2 folds	Seal		3 folds	Seal
Reinforcement

© 2009 Bendix Commercial Vehicle Systems LLC All rights reserved. 9/2009 Printed in U.S.A.