This procedure allows manual release for Maxibrake™ installations with at least 3.0" of exposed threadedrod between the jam nut at the clevis and the jam nut at the Maxibrake™ piston tube.

Haldex Limited

525 Southgate Drive, Unit 1Guelph, ON Canada N1G 3W6

Phone: 519-826-7723Fax: 519-826-9497

Haldex Brake Products Corporation10930 N. Pomona Ave.

Kansas City, MO 64153 -1297Phone: (816) 891- 2470

Fax: (816) 891-9447

Haldex Commercial Vehicle Systems

www.haldex.com

serviceBulletin

Maxibrake™ Spring Brake Release Procedure

L55259W US 10/08 WEB ONLY

CAUTION: When working on the brake system, make sure the vehicle wheels are securely blocked orthe vehicle is securely raised on a hoist system. Place jack stands only at the designated chassis supportpoints. Make sure the stands are rated to safely support the weight of the vehicle. As a safety precaution,always use jackstands after the vehicle is hoisted.

DO NOT disconnect the push rod clevis from the brake adjuster or remove the brake chamber from themounting bracket when the spring brake is applied. The push rod is extended when the spring brakesare applied (on). The parking brake power spring is still under high tension even when the push rod isfully extended.

1. Block the vehicle wheels securely to prevent it from moving.

2. If the Maxibrake™ is equipped with a dust boot, cut and remove the nylon tie strap on the small end of the boot. Then cut and remove the rubber boot and bushing from the push rod.

3. Remove road grime and rust from the push rod threads for a minimum of 3.0" adjacent to the jam nut at the Maxibrake™ piston tube using a wire brush as required. Clean the threads and spray with an all purpose lubricant such as WD-40®.

4. Loosen and back off the jam nut at the Maxibrake™ pistontube approximately 3.0". Then back off the flange nut at the piston tube until the wheel end brake releases. Repeat this procedure for all applied spring brakes.

5. The vehicle is now ready for towing.

Maxibrake“R” Series

Spring Brake

WARNING: Spring brakes are under compressed spring force. Never removethe cylinder assembly cap screws unless the spring cylinder is restrained in apress. Maintenance and repair must be performed in full accordance with themanufacturer’s written instructions contained in L31112 Service Instructions.

CAUTION: Haldex Maxibrake spring brake products are mechanical deviceswhich are subject to wear after extended use. Inspection and service of the unitat regular intervals, but no less than once per year, is recommended. Partsshowing signs of wear, deterioration or damage need to be replaced to insuremaximum operating efficiency. Haldex recommended service procedures canbe found in L90280 Preventative Maintenance Schedule.

!WARNING! WARNING!

L31081Rev. 7/02

North American Sales DivisionHaldex Brake Products Corp.

10707 NW Airworld DriveKansas City, MO 64153-1215

Phone: (816) 891-2470Fax: (816) 801-4198

North American Sales DivisionHaldex Limited

525 Southgate Drive, Unit 1Guelph, Ontario Canada N1G 3W6

Phone: (519) 826-7723Fax: (519) 826-9497

Rev. 7/02 1.5M ART L31081

!

Instructions For Application OfMaxibrake I & R Series Service

Kit Parts (Steel Piston)1. Apply an even coating of TR-3 lubricant to the cylinder

bore.

2. Install the nylon bushing into the outer groove in the

cylinder center boss. The sharp corner on the inside

diameter of the bushing must be oriented toward the

outside of the cylinder.

3. Apply TR-3 lubricant to the inner groove in the cylinder

center boss and the small o-ring. Install the o-ring in

the groove.

4. Install the bearing on the piston assembly making sure

the radiused inside edge is resting against the radius at

the piston lip. Remove the push rod bushing from the

piston for R-Series actuators.

5. Apply TR-3 lubricant to the piston between the bearing

and the wire ring.

6. Coat the large o-ring with TR-3 lubricant and install the

o-ring on the piston between the bearing and wire ring.

7. For type 24, 30 & 36 Maxibrake actuators, install the felt

wiper in the groove on the piston bearing. Insert the

piston assembly into the cylinder while holding the

bearing and felt in place.

8. For Maxibrake Type 20 and R-Series actuators, install the

felt wiper in the groove on the piston bearing. Apply the

bearing compressor strap to hold the felt and bearing in

place. Insert the piston assembly into the cylinder. The

bearing compressor will slide off and can be reused.

9. Push the piston to the bottom of the cylinder and continue

with reassembly. Check to be sure the push rod bushing

is installed in Maxibrake I Series assemblies and

absent in Maxibrake R Series assemblies.

Installation InstructionsMaxibrake I & R SeriesService Part Kit

InstallationGuide

L31090 Rev. 2/07

Instructions For Application OfMaxibrake I & R Series Service

Kit Parts (Aluminum Piston)1. Apply an even coating of TR-3 lubricant to the

cylinder bore.

2. Install the nylon bearing into the outer groove in

the center boss of the cylinder. The sharp corner on

the inside diameter of the bearing must be oriented

toward the outside of the cylinder.

3. Apply TR-3 lubricant to the inner groove of the

cylinder center boss and coat the small o-ring.

Install the small o-ring in the inside groove in the

cylinder boss.

Aluminum Piston Instructions (Continued)

4. Apply TR-3 lubricant to the center groove in the piston

and coat the large o-ring. Install the large o-ring in the

center groove on the piston.

5. Install the felt wiper in the piston groove nearest the

open end of the piston casting.

6. Insert the piston into the cylinder so the piston insert

tube goes through the cylinder center boss and push the

piston to the bottom of the cylinder and continue with

reassembly. Check to make sure the push rod bushing

is installed in Maxibrake I and absent in Maxibrake

R Series assemblies.

(Aluminum Piston)

(Steel Piston)