Selecting the right Aircoil - TMC RP417 provides guidelines regarding the selection of Aircoils. We have captured some of this information for your reference.
Measure the distance between the tractor and trailer hookup points at the point of greatest extension during a full right turn articulation. Note that in the case of lines that are suspended off the deck by a clamp, the point at which the tubing is clamped (rather than the tractor protection valve), should be considered the tractor connection point for purposes of this measurement.
Measurement between tractor & trailer hookup points:
Less than 8 ft. - Recommended Working Length: 12 ft.
Between 8-10 ft. - Recommended Working Length: 15 ft.
More than 10 ft. - Recommended Working Length: 20 ft.
Note: If a short tractor lead is being used OR if a long tractor lead is being clamped directly to the cab, it is wise to select the next working length up from what is recommended. Utilizing a tender spring or pogo stick offers a greater lateral & rearward movement of the lines, enabling their full working length to extend during turns.
Tractor Lead Length
Most new tractors have less than an 18" distance between the tractor air connection and the deck. This makes hookups more accessible to the user but requires that the lines have a longer lead and some method of suspension to protect them from abrasion. The rule of thumb is to use a longer lead length if the hookup distance is less than 18” from the deck.
In addition to standard lengths of between 6” and 12” depending on the working length, Tectran offers options of 24", 48” or 72” with proper spring guard protection on this entire length according to FMVSS requirements. It is critical that aircoil tractor leads be clamped on the spring guard protected section rather than onto the tubing to prevent kinking.
For proper suspension of the longer tractor leads, consult our General Section for a wide range of pogo sticks, tender kits and slider bars.