Power

FRONT DISPLACER SWAP

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 don’t wait until it has failed completely leaving you with a lop-sided Wedge, as changing a displacer isn’t 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.

So, what will hopefully be the first of many tutorials, I’ll show you how to remove and replace a front displacer step by step. This procedure applies to both front offside and nearside displacers, though the following shows the removal of a nearside displacer.

You will need the following tools:

· Suitable jack and axle stands

· 3/8” and/or ½” 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.

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 won’t go into details as I don’t want anybody to get hurt! It’s up to you… If the suspension has collapsed anyway, then the above won’t 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. On the appropriate side, pull back the carpet in the front footwell to reveal the through-bolt and pull it clear. A tap from a hammer may be necessary.

Manoeuvre the upper swivel arm out of the bulkhead…

to reveal the displacer.

Step 5.

From the engine compartment, undo the displacer union nut using a 24mm spanner and move it aside…

then manoeuvre the displacer out of the bulkhead.

Refitting is a reversal of the removal procedure. Once reassembled have the suspension system repressurised on a flat, level surface so that the ride height is 14½” from the wheel centre to the centre of the wheel arch.

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

18^th June 2007.