Installing Air Spring on Severe-service Vehicles
Use the following procedure to install the air spring for the Hendrickson Primaax suspension in severe-duty vehicles:

  • Prepare the frame rail for the upper air-spring shield. Using a wire brush or sandpaper, remove any loose paint, rust or scale from the underside surface of the frame rail where the upper air-spring shield will be installed. Lightly sand this area to roughen any glossy surfaces. Clean with soap and water, rinse and let dry.
  • Remove the adhesive backing and install the upper air-spring shield to the underside of the frame rail range, extending 1/2 inch to 3/4 inch over the frame rail flange, as shown in Figure 1.
  • Install the lower air-spring shield over the support beam assembly end and air spring locator tab. Ensure the slots in the lower air-spring shield engage the lower air spring mounting studs, per Figure 2.
  • Install the air spring between the frame and cross brace so that the locating tab engages the “V” notch in the end cap.
  • Hold the air spring tight against the lower frame rail flange and tighten the upper air spring mounting fastener per original equipment manufacturer’s specifications.
  • Install the lower air spring mounting bracket around the cross brace, engaging the mounting studs on the air spring.
  • Using hand tools only, install the lower mounting fasteners. Tighten the locknut to 20 to 30 ft.-lbs., as in Figure 3.
  • Connect the air line to the air spring.
  • Inflate the suspension by connecting the height control valve linkage assembly to the height control valve arm. Verify the air springs inflate uniformly without binding.
  • Remove the frame supports.
  • Remove the wheel chocks.
  • Verify proper ride height adjustment.

New Guide Spring
A new narrower guide spring for the camshaft lifter is now being used on Caterpillar C9 engines. This will eliminate the chance of the spring becoming bent or broken.

Bent or broken guide springs can lead to damaged lobes on the cam and valve lifters.


Purge Pump & Service Pack
A new purge pump and service pack now are used on Caterpillar C13 (S/N: LEE1-Up) and C15 (S/N: SDP1-Up) engines. The new pump and service pack now have larger inlet and outlet ports.

Additional parts are required to connect the pump and the pack to existing lines and connections.


V-band Clamps for Air Inlet Connections
Effective May 1, 2006 (beginning with engine S/N: 6H1779), Mack implemented a heavy-duty V-band clamp (Part No. 1809GB329BM) into production for the elbow connection at the inlet manifold on ASET AI and AMI engines, as shown in Figure 4.

It replaces the previously used worm-screw-type clamp (Part No. 180GB329[A]M). This revised clamp is a T-bolt-type clamp that utilizes a quick-latch feature. When installing this clamp, apply a thin film of engine oil around the inside diameter of the clamp and tighten the T-bolt nut to 8 +/-0.5 Nm (70 +/-5 lb.-in.).

On about January 1, 2008, the 180GB329BM clamp was superseded by clamp Part No. 180GB339M. The fit, form and function of the 180GB339M clamp are the same as previous clamps.


Safety Recalls
The National Highway Traffic Safety Administration (NHTSA) has issued the following recalls:

  • On 292 aftermarket SAF-Holland fifth wheels sold for use on model year 2007 Kenworth T800 short hood, W900 long hood and T600 tractor/trailers, if the pivot bolt for the lever bar is over-torqued, the spacer deforms and makes contact with the lever bar. This condition, coupled with corrosion associated with the seasonal dry out, can affect the lock system of the fifth wheel, preventing the fifth wheel jaw from latching securely around the trailer king pin.

    The fifth wheel may fail to latch without the operator’s knowledge, causing the tractor and trailer to disengage, increasing the risk of a crash.

    Pivot bolt joints must be inspected for a deformed spacer, and if problems are found, replace the bolt, washer and spacer with a hex-head shoulder bolt and washer.

  • Nine hundred 2008 model year Freightliner Argosy, Argosy RHD, Cascadia, Columbia, Century ST, Coronado, Sterling Acterra, L-Line and Western Star 4900 trucks equipped with Bendix MV-3 dash control valves are being recalled. The molded valve body has an incorrect core pin in the injection mold causing the valve to be oversized in the double check valve area.

    This condition can allow the rubber double-check valve to become lodged in the body opening under certain conditions. If the double-check valve becomes lodged, in the event of a primary reservoir failure, air pressure can leak past the lodged double-check valve, thereby depleting the secondary reservoir and reducing the ability for modulating the service emergency brakes, increasing the risk of a crash.

  • The suspensions on 706 2003 to 2008 model year Kidron van trailers equipped with fixed spring suspensions with a pintle hook option installed may crack in the G-rails area between the pintle hook box assembly attachment and the rear spring hanger attachment. Cracks over time will continue until the pintle hook box attachment becomes unsafe for doubles operations, increasing the risk of a crash.
  • Certain Phillips QCS II trailer cable connections and trailer cable mounting brackets with U-shaped cut outs on Kenworth C500, T800, T600, T2000 and W900 model year 2007 chassis may only partially support the trailer cable connection. Partial support of the cable connection may allow the molded boot and the electrical ground pin to partially or completely pull away from the 7-way socket.

    Partial or complete detachment of the cable connection can cause reduced water resistance and a potential loss of electrical ground. There also is a possibility the trailer lights may fail to illuminate without the operator’s knowledge. If this condition occurs, other motorists may not be warned of the tractor/trailer movements, increasing the risk of crash.

    A reinforcement bracket needs to be installed between the flexible back of the QCS II molded boot and the frame bracket and the supporting bolts need to be reattached.

  • The two vertical right/left side front spring bracket bolts on 16,805 model year 2005 to 2008 Hino NA6J, NC6J, ND8J, NE8J and NV8J trucks were not tightened properly during the assembly process. This may cause increased stress on the spring bracket, which can lead to cracking of the bracket. This can reduce steering control and increase the risk of a crash.
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