High pressure Rubber Hose 648mm (25") long with a straight union at one end and a 90 degree union at the other; suitable for use with RTR axial flow (Bosch style) Pump Kits. N.B. See note regarding fuel smell.

Use this rubber hose to replace 215642, Hose Pump to Pressure Relief Valve (PRV), when resonance in the PRV is experienced. The standard hose gets hard and amplifies a resonance set up in the PRV when an axial flow pump is used; by using this hose which is slightly longer than standard, experience has shown that in most cases the extra length of this hose moves the resonant frequency enough for the problem to disappear.

An even longer hose will be required if your PRV is still mounted on the chassis, (TR5 & earlyTR6); order 215585 or 215585SS, see below.

NOTE 1: We have found that braided stainless steel hose cannot be used in this position whilst the original PRV is still used due to the hard nature of the outer sheath, causing even more resonance. See note 2 for a diferent design of PRV.

NOTE 2: Resonance is when the PRV fluctuates at a resonant frequency with the pulses generated by the fuel pump and an unpleasant droning noise is produced. This phenomenon is unlikely to occur with the original Lucas pump but is very likely when an axial pump is fitted. This longer soft hose RTR4048 when fitted from the pump to the original PRV usually cures this (a stainless Steel braded hose will make it worse) but brings with it another bit of bad news. As modern fuels are much more volatile than older fuels they can permeate through rubber hose and create an unpleasant smell in the boot. If this is unacceptable there is a definitive solution to all this. We have a modern PRV kit available RTR4456K which works on a different principle to the original type and does not resonate. The good news is that with this new PRV kit installed a Teflon lined Stainless Steel braided hose, 215642SS or RTR4048-1 can be used from the pump to the PRV which will greatly reduce petrol smells in the boot with no fear of resonance.

Before ordering 215642SS or RTR4048-1 (assuming you are changing to the new design PRV) inspect your axial flow fuel pump installation and choose the most appropriate hose. If you have a RevingtonTR axial flow fuel pump kit mounted externally under the left hand boot floor, 215642SS is likely to be your best choice.
215642SS has 90 degree fittings both ends and is 460mm (18-1/8") long
RTR4048-1 has a 90 degree fitting one end and a straight fitting the other and is 648mm (25") long

This part is listed on the following pages of the website, where further information and background reading may be found.

Fuel and braking systems » PETROL INJECTION COMPLETE PUMP KITS TR5-6
Information Sheets » IS0006 - Replacing Lucas P.I. Pumps with Axial (Bosch type) Fuel Pumps and Tuning