Air Bag Suspension in Mercury

I recently acquired an 89 Mercury Grand Marquis Colony Park. It has the auto load-leveling suspension. I've been told that it uses air bags of some
sort. Do these air bags replace the springs? The air pump for them seems to be cycling frequently. I'm assuming that means there's a leak. How hard are these to change?
CJB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I own a 95 TC. I assume the systems are similar.
If you hear the compressor running when you first start the vehicle, that's normal. The system vents after you turn off the car and close the door. I suppose it's a self-test procedure. What isn't normal is for the compressor to run often while driving.
Make sure you turn the air suspension off before you work on your car!
Two easy ways to test for a leak:
1) Raise the car up and inspect the air springs for cracks. Normally the spring will crack near the bottom fold, but I suppose it could crack anywhere. 2) Turn the air suspension off and drive the car for a while. If the rear sinks, you've got a leak.
My original air springs lasted 9 years and 100,000 miles before they developed leaks. Your mileage may vary. The symptoms I experienced was that the compressor would run often while driving, and if I took a long road trip the "check air suspension" lamp would come on about two hours into the trip.
I found the air bags easy to change. You can probably do it one afternoon if you are handy. I bought some aftermarket springs first, but they did not fit. I ended up buying Ford springs and then the job was easy. The air fittings are a little difficult to disconnect, IMO, but otherwise the job was easy. If you have questions feel free to ask. I also replaced the compressor, dryer, and vent solenoids when I did mine. Total cost for parts was $600 including tax.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for your input. After hearing your description, I don't think the air bags are leaking. I was just a little unnerved by the long pump time each time it start it up.
CJB

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.