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Let the pressure escape
Page 105
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• Operators with trucks or trailers which are fitted with Norde tandem-axle suspensions should be aware of a slight risk of an explosion when using heat to remove bushings from the suspension centre box.
It is to be emphasised that this applies only to suspensions built before 1981, and that only two cases have been reported.
On earlier suspensions, the centre box was not fitted with a vent hole, so that if heat is applied, there is the danger that the air and oil contained in the box could expand dangerously quickly.
Hendrickson Norde's Service Department advises that if it is necessary to apply heat to the centre box on pre-1981 suspensions (typically when using a cutting torch to remove the bonded rubber bush or beam centre pin) a small vent hole should first be drilled through the side or top plate of the centre box.
It is important that the drilling does not penetrate a weld or the toe of a weld. After removal of the centre box a further hole of 6mm diameter should be drilled in the centre of the bottom plate. The first hole in the side or the top should then be welded or plugged up.