The D.W.S Permanent Hydraulic Jacking System.
A number of pre-war vehicles were fitted with a system of four hydraulic jacks, one being permanently mounted near each road wheel. These include the Rolls-Royce Phantom 3 and the Wraith, as well as a number of other marques such as Alvis and Lagonda. In many cases the jacks are now no longer operational, having been neglected over the years.
Each jack consists of a double extending telescopic hydraulic ram that is controlled from a pump operated from within the car. Either the two front jacks can be used together, or the two rear, or all four jacks used at the same time to lift all four wheels off the ground simultaneously.
For satisfactory operation of the jacking system it is essential that the rubber hydraulic seals within the rams are all in good order, and the surfaces that they seal against are free from corrosion and have a smooth and polished finish. Without this the rams will leak, and will not retract satisfactorily after use. Similarly it is essential that there are no leaks within the pump unit either due to perished seals or damage to the pump itself.
In our experience just replacing the rubber seals in the system will help only a small number of those jacks requiring attention. Consequently we have re-manufactured the extending telescopic tubes, using a superior grade of steel for extra strength. These have been given a surface treatment which both protects the surface against future corrosion and offers a hard-wearing surface for an extended life. The internal working surfaces of the tubes have been ground and then polished to a near-mirror finish.
We can supply complete jack units that are largely new, and we can also overhaul the complete system on a vehicle to restore it to full working order.