As Featured in Practical Classics
and Autocar Magazine
Hydragas displacer units gradually lose their gas over time. This is perfectly normal, when new they had a design life of approximately 15 years. The majority of units are now over 30 years old and most are so low on gas that the ride quality they give is now severely compromised. Comfort Is poor and the car crashes over bumps, the ride height diminishes and pumping up the suspension to the correct height again makes the ride even harsher. Continuing to use the car with the suspension in this condition is not only unpleasant for the driver and passengers, it can shorten the life of the displacers and these have been out of production for many years. Replacing with second hand or new old stock nearly always gives disappointing results as they are still suffering from loss of gas as this occurs over time regardless of mileage or whether the units have been previously used.
The good news is we provide a re-gasing service for all Hydragas Displacer Units which will bring back the smooth and supple ride this unique suspension system is renowned for, all the customer needs to do is remove them from the car and send or deliver them to us or we offer a full removal, re-gas, re-fitment and pump service for all Hydragas cars with a two day turnaround for the entire job at our premises in Telford, Shropshire.
Before we start work we thoroughly check the unit(s) for fluid leaks, we then drill into the gas chamber to release what's left of the old gas and provide the means of entry for the new gas. A special collar is then welded to the displacer, a high pressure Schrader valve is fitted and the unit charged with fresh Nitrogen to the original specified pressures, the unit is again thoroughly tested for fluid and gas leaks. If we do find a defective unit (fortunately this doesn't happen very often) we contact the customer straight away and give them the opportunity to send us another unit, if we encounter a defective unit there is no charge for that particular unit.
On Austin and MG Metro models we fit the valve in an offset position so when the unit is re-fitted to the car it won't foul on the front inner wing which partially covers the top of the unit. The same applies to MGF rears to avoid any fouling on adjacent components. On MGF and Rover Metro front units the inner wing strengthener is larger and completely covers the top of the displacer, therefore we fit the valve to the side of the units on these models so there are no concerns on re-fitting.