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The Hydragas displacers fitted to the Princess and Ambassador usually give plenty of warning that they are soon to expire; frequent pumping up of the suspension or knocking noises are sure signs that all is not well, but occasionally they can and do fail without warning. But donít wait until it has failed completely leaving you with a lop-sided Wedge as changing a displacer isnít fraught with as many complications as you might think.

But, before you go ahead, make sure you have access to a suspension pump, either at your local garage or specialist; driving a Wedge on its bump stops is not a pleasant experience! Suspension pumps regularly crop up for sale and ebay is a good source for them, but you have to weigh up whether they are worth the expense.

Iíll show you how to remove and replace a front displacer step by step. This procedure applies to both front offside and nearside displacers, though this tutorial shows the near sideís removal.

You will need the following tools:

         Suitable jack and axle stands

         3/8Ē and/or ĹĒ socket driver.

         13mm socket.

         13mm and 24mm open ended spanner.

         19mm spanner or deep socket

         32mm socket.

         Ball joint separator

         Suitable hammer.

         Suspension pump, or access to one.

Refitting is a reversal of the removal procedure. Once reassembled have the suspension system repressurised on a flat, level surface, handbrake off, so that the ride height is 14ĹĒ from the wheel centre to the centre bottom of the wheel arch.

I hope to be able show you a rear displacer swap someday, but itís a bit more complicated, mainly because the pivot shaft sometimes seizes into the radius arm. Iíve seen it happen twice!























Step 1.


From within the engine compartment locate the Schraeder type fluid displacer valve applicable to which side the displacer is to be removed. You can discharge the fluid either by using a proper suspension pump, or you can do it manually by pushing the valve in. The procedure for this is similar to letting a tyre down, but I wonít go into details as I donít want anybody to get hurt! Itís up to youÖ If the suspension has collapsed anyway, then the above wonít really be necessary.

Step 2.


Raise the front of the car, remove the appropriate front roadwheel and support the car securely with an axle stand.




Using a 19mm spanner or socket, undo the upper arm swivel joint nut, then use a suitable ball-joint separator to separate the hub from the upper arm. Use a suitable support for the hub assembly to avoid straining the brake hoses.

Step 3.






Using a 13mm socket undo the four bolts on the bump stop plate. Note that, depending on which side you are removing, one of the top two bolts reaches through to the engine compartment and has a 13mm nut on the end. Remove the bump stop plate.

Step 4.


Locate the upper swivel arm bolt nut and undo it using a 32mm socket. Recover the washer.