ROAD and WORKSHOP y a
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Lndyman
A Time-saver for the Breakdown Kit
tOADSIDE BREAKDOWNS of cornaercial vehicles, although reducing in lumber, and the subsequent delay, are till a matter of concern to the transport .ngineer. Particularly so when a team is ent some miles to deal with fuel trouble Lnd are still searching amongst pipe tnions. filter joints and lift pump several tours later. Even the best fitter can be aught out and on a really bad night a imple air leak into the fuel lines can ;ause real delay to vehicle and load, o that by the time the fault is cleared tours may have passed and the driver an be at or near the end of his legal vork ing shift.
A solution to the problem is provided )3/ a little gadget that can he made up rery quickly and cheaply and can reduce he worst air leak problem from hours
o minutes. The main requirement is a :omplete inflator neck and Schrader valve 'roni a vehicle tube—and the longer the )etter. This is brazed into a pipe union n' adaptor that will couple directly into he fuel line at the fuel tank end. A leek round the fleet will establish the size )f any that may vary in pipe diameter )r threads per inch, and in any case this )roblem can be overcome by Simplex tdaptors or by making up several attachnents to cover the range. In most cases tmong the heavier vehicles three will ;over the fleet.
The next item is an ordinary foot pump, and with the adaptor and inflator neck now coupled into the line the pump :onnection is snapped on and ready to xst. Even with a bad air leak there is always a little fuel in the line, but if not a little can he introduced and one or two strokes of the pump will soon show results by wetting the area of any leak. Before making the test the line should be disconnected at the lift pump and a " blind " union screwed on to the pipe, then pressure can be applied safely with no possibility of damage to the pump diaphragm or valves. Obviously there is no need to test beyond the lift pump, as any leak from there on would be outwards and show as fuel loss: the a:r can only intrude on the suction side, between pump and tank. If the lift pump is suspected of passing air into the system it can be tested with the
thumb whilst disconnected; place the thumb over the pump inlet and operate the priming lever or plunger. With the thumb sealing the inlet, the plunger-type primer will try to resist upward movement if airtight, just as the lever type can be moved over and will not return if the exit is blocked. Either way, it is easy to establish if the pump is passing air.
The gadget described has several applications and can be used in workshops or on the road. It will also provide a speedy answer in the location of vacuum leakage. Here, a useful trick is to braze a connector into a spare vacuum tank drain plug, but instead of oil as a leak indicator a mixture of soap and water is used. The same mixture, incidentally, works just as well when dealing with Westinghouse or Clayton air brake systems. Once in the breakdown kit, this little gadget is worth its weight in gold.