Installation And Adjustment Instructions For Kobelt Disc Brake Caliper Model 5019-5028

Brake disc installation

It is important to remember that the brake disc itself must be installed onto the rotating element before installing the caliper. This will then allow proper alignment of the brake caliper to the disc. The disc mounting bolts must be suitable to absorb the brake torque plus and shock load in the system. For high temperature disc applications, the holes for the mounting bolts must be oversized to allow the disc to expand and contract during operation.

Brake caliper installation

The foundation plate to support the brake caliper must be strong enough to withstand the maximum torque generated by the brake caliper. It must also be flat and square to the brake disc. The bolts holding the brake caliper to the foundation plate must be grade five or better, properly torqued and under no circumstances can there be a bolt missing. The bolts should also be long enough to accept a full sized nut. Failing to do so could cause the foot of the brake to fail. It is possible with these brakes to loosen the assembly bolts (nuts), and raise the whole caliper arrangement away from the foot to allow easier installation of the mounting bolts into the brake foot. After the bolts are in place be sure to re-tighten the bolts (nuts).

The clearance between the brake shoe and disc should be equally divided on both sides. The shoe must be parallel to the disc. The rugged design of Kobelt brake calipers allows for some inaccuracy without affecting the performance. Shims can be placed between the shoe bearing and the shoe to allow the calipers to be adapted to various sizes of disc thicknesses. The actuators themselves have an adjustable clevis to allow for brake lining wear or to adapt to various sizes of discs. It is important that the clearance between the shoes and disc is kept at a minimum without causing drag. The clearance should not exceed .040" (1.0mm) per side. This will allow for fast response and a minimum of fluid consumption with fluid applied actuator. On spring applied calipers a minimum of clearance is necessary to maintain maximum brake torque.

Initial disc brake start up

Even if a disc brake is installed according to specifications, full brake torque may not be obtained on the initial start-up. This may be due to residual grease or oil deposits on either the brake lining or disc. Under no circumstances should the brake be started with oil or grease on the disc. It is important that the lining is burnished to obtain full lining contact with the disc. During the burnishing operation the disc should be heated to approximately 400º F to 550º F, to burn off all the grease and lubricants from the disc and lining. Care must be taken not to over heat the disc during this process. After the brake has been cycled (applied and released under maximum conditions) It is important to check all fasteners for tightness. It is the experience of Kobelt Manufacturing that bolts, studs, and nuts settle in after the brake has been in use, and it is therefore important that all fasteners are checked after initial start up at reasonable intervals.

Spring applied actuators with manual release screws

All Kobelt spring applied actuators can be supplied with manual release screws. This release screw serves to release the brake upon failure of the fluid pressure. It is very important that the fluid supply line is open to tank or atmosphere when winding the manual release screw inward, since the piston cavity requires a fluid supply source when doing this. This holds especially true in hydraulic systems, where a vacuum plus the spring tension is generated. The manual release screw mechanism will fail if no source of fluid supply is available.

CLEARANCE ADJUSTMENT

Before making any adjustment ensure that the brake is released.

	Spring Applied Actuator The clearance can be adjusted by removing pin "A"and by turning clevis "B". It can further be adjusted by loosening jam nut "C". Then removing bolts in bracket "D" and rotating same.
	Fluid Applied Actuator Remove both pins "A" and turn both clevises an equal amount. Turn counter clockwise to decrease clearance and clockwise to increase clearance.

Balancing Link Adjustment All calipers are equipped with balancing links to ensure even lining wear. To adjust, loosen screws "B" and adjust link "A" to align the shoe parallel with the disc. Shim Kits In order to adapt a caliper for a thinner disc shim kits are available. These shims "D" fit between the brake shoe and the bearing. See product sheets for ordering information. Lining Replacement It is important to replace the lining before the rivets make contact with the disc. By removing screws "C" or pin "E" The shoes can be taken off the caliper assembly. Drill out rivets and install new lining with the proper rivets. When re-installing shoes into the caliper assembly be sure to re-engage the balancing link "A".

ACUTATOR MAINTENANCE

Kobelt actuators require very little maintenance. However should it become necessary to replace seals, proceed as follows:

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