1978 MACK WL Recalls (5)
- Campaign:
- 79V133000 on 10/11/1979
- Component:
- Engine and engine cooling:engine
- Manufactured:
- 01/31/1977 - 02/28/1979
- Affected:
- 23,000
- Defect:
- In the event of turbocharger compressor wheel failure, one or more of the four capscrews that hold the turbocharger together may be struck by parts of the compressor wheel, resulting in the capscrews being damaged. if these capscrews are damaged to the point that they allow the compressor back plate to dislocate from the turbocharger bearing housing, engine lubricating oil may be allowed to escape under pressure, contacting the engine exhaust manifold sections or turbocharger turbine housing.
- Correction:
- Dealer will install a shield for the heads of the four capscrews, along with stronger sae 8 grade 8 capscrews, if necessary, at no cost to owner.
- Notes:
- Vehicle description: trucks equipped with endt (b) 676, etaz (b) 673a, and etay(b) 673a engines.system: engine and engine cooling.consequences of defect: engine lubricating oil, in the presence of a source ofignition, could lead to an engine compartment fire and serious injury tovehicle passengers.
- Campaign:
- 79V137000 on 10/11/1979
- Component:
- Steering:linkages
- Manufactured:
- 04/30/1977 - 03/31/1979
- Affected:
- 6,673
- Defect:
- The pitman arm retaining nut may not have been torqued to manufacturer specifications. this could result in inadequate retention of the nut at the output shaft, allowing the pitman arm to become loose.
- Correction:
- Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
- Notes:
- Vehicle description: trucks.system: steering linkages; arm, pitman.consequences of defect: this condition could lead to premature wearing of theoutput shaft causing loss of vehicle control and an accident.
- Campaign:
- 78V210000 on 10/11/1979
- Component:
- Service brakes, air:antilock:interconnecting assembly(wiring)
- Manufactured:
- 09/30/1977 - 08/31/1978
- Affected:
- 19,370
- Defect:
- Delays of up to about 2 seconds may exist in the brake application times to the brakes on the bogie axles in the presence of certain types of wheel speed sensor signal discontinuities or distortions that may occur as a result of sensor wire failure. this constitutes a non-compliance to federal motor vehicle safety standard no. 121, "air brake systems".
- Correction:
- Dealer will install new wheel speed sensors that incorporate improved wiring and the present bogie anti-wheel lock system will be changed to an axle-to-axle system for improved reliability.
- Notes:
- Vehicle description: heavy trucks.system: service brakes; electrical wiring and connectors.consequences of defect: this delay in effective braking action could lead to anaccident under certain traffic conditions.
- Campaign:
- 78V030000 on 10/11/1979
- Component:
- Service brakes, air:supply:hoses, lines/piping, and fittings
- Manufactured:
- 11/30/1975 - 12/31/1977
- Affected:
- 400
- Defect:
- A design deficiency exists in the air dryer piping in the area of the pressure relief valve and compressor governor control link. moisture is passed and builds up in this relief valve and control line. in freezing ambient temperatures, this moisture may freeze, allowing the chassis air system pressure to exceed 150 psi. excessive air system pressure can cause separation of air piping connections and air system valve failure.
- Correction:
- The dealer will relocate the air system compressor governor line and pressure relief valve to eliminate moisture accumulation.
- Notes:
- Vehicle description: trucks equipped with anchorlok air dryers.system: service brakes; air system and governor control line (air dryer).consequences of defect: when this occurs, automatic application of the chassisemergency spring brakes and trailer brakes could cause loss of vehicle controlwithout prior warning and a vehicle accident.note: owner/driver is advised not to operate vehicle if air pressure exceeds15o psi.
- Campaign:
- 78V170000 on 10/11/1979
- Component:
- Engine and engine cooling:engine
- Affected:
- 850
- Defect:
- The possibility exists that the aluminum engine rear support brackets may fail due to metal fatigue. this type of failure would allow the engine and transmission assembly to dislocate downward. this will result in throttle control loss with the engine operating continuously in the mid to upper range of the governed speed range.
- Correction:
- Dealer will inspect and, if necessary, replace aluminum support brackets with brackets made from ductile iron for increased strength.
- Notes:
- Vehicle description: trucks.system: engine; engine mounting bracket.consequences of defect: loss of throttle control may result in loss of vehiclecontrol and an accident.
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