1974 MACK F Recalls (5)
- Campaign:
- 78V068000 on 10/11/1979
- Component:
- Service brakes, air:antilock:control unit/module
- Manufactured:
- 09/30/1974 - 02/29/1976
- Affected:
- 9,700
- Defect:
- An axle "no brake" condition could result from an eaton controller internal electrical malfunction. this condition may cause the anti-wheel lock valve solenoid to be continuously energized and prevent the brakes from being applied on one of the axles. as a result, the anti-wheel lock warning lamp is not activated.
- Correction:
- The dealer will inspect and, if necessary, replace the anti-wheel lock controller without charge to owner.
- Notes:
- Vehicle description: trucks equipped with eaton 21 anti-lock controllers.system: service brakes; anti-wheel lock solenoid.consequences of defect: loss of brakes on any one axle will result in extendedvehicle stopping distances, which could lead to a vehicle accident.
- Campaign:
- 78V171000 on 10/11/1979
- Component:
- Steering:linkages:knuckle:spindle:arm
- Affected:
- 2,100
- Defect:
- Deficiencies, in the form of forging laps, cracks and excessive decarburization during heat treatment, exist in the steering knuckles. stresses imposed with integral hydraulic power steering may lead to a failure in the area of the steering arm attaching boss. this type of failure would cause loss of steering control.
- Correction:
- Dealer will inspect and, if necessary, replace the left steering knuckle with an improved type of knuckle.
- Notes:
- Vehicle description: truck tractors.system: steering; steering knuckle.consequences of defect: loss of steering control could cause a vehicleaccident.
- Campaign:
- 77V173000 on 10/11/1979
- Component:
- Engine and engine cooling:cooling system:fan
- Affected:
- 48,000
- Defect:
- The flex blade fans on the involved vehicles may develop cracks in the laminated stiffener as a result of fatigue during operation. if such a condition exists and the cracks go undetected, continued operation could cause pieces of the stiffener to break off.
- Correction:
- Dealer will replace the original fan with a steel fixed blade fan, free of charge.
- Notes:
- Vehicle description: trucks equipped with six-cylinder engines.system: engine cooling; fan.consequences of defect: broken pieces can be propelled outside of the fanshroud and will present an immediate danger and possible injury to personsstanding nearby.note: prior to correction, vehicle should not be serviced with the hood raisedand the engine running.
- Campaign:
- 75V192000 on 10/11/1979
- Component:
- Service brakes, air:supply:hoses, lines/piping, and fittings
- Affected:
- 1,200
- Notes:
- Mack campaign no n/a.trucks with dual brake treadle valve piping sept.1974and mar.31, 1975.possibility that the primary and secondary air supplylines may have been connected in reverse at the dual brake treadle valve.thereversing of these supply lines does not in itself, affect vehicle braking ifboth the primary and secondary air supply systems have normal operating airpressure.however, in the event of loss of air pressure in either the primaryor secondary system, neither the primary nor secondary service brakes wouldfunction when applied.in this event, it would require manual application ofthe emergency spring brake to stop vehicle.(correct by inspecting andrerouting air supply piping as required to correct system).
- Campaign:
- 75V193000 on 10/11/1979
- Component:
- Service brakes, air:supply:hoses, lines/piping, and fittings
- Affected:
- 2,250
- Notes:
- Mack campaign no q1012.trucks sept.2, 1974 thru july 30, 1975.possibilitythat an error was made in the installation of the air supply piping to thetractor trailer park valve manifold.if this occurs, the primary air supplysystem becomes the sole source for supply air to the tractor trailer park valvein this condition, tractor or trailer brake operation is not affected, as longas the primary system has normal operating air pressure.however,in this couldbe hazardous to either the primary system, there will be a corresponding lossof air to the tractor trailer park valve0 and this valve, by design, willautomatically apply the emergency spring brakes, which then could only bereleased mechanically.an automatic application of the emergency spring brakeswould immobilize the vehicle and require mechanical release wheel by wheel.this could be hazordous to either the vehicle operator or to the individualreleasing the brakes.(correct by inspecting and changing piping to proper airsupply system).
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