My 99 Park Ave has 130,000 miles and the rear struts seem tired. When there is a load in teh trunk it sags, and the compressor seems to kick in, but it doesn't raise teh rear end back up to level any more. Does anyone have any experience with this model? Could you recommend a brand of struts. Is there a test procedure to see it the compressor is still working properly?

Sounds like the compressor is working, just the shocks are bad. Check Rock Auto or Advance Auto Parts. Monroe Max-Airs are about $75.00 a pair. They are easy to install (about an hour) and fit the original air lines. If you order them online find a promo code to include in your order. Rock Autos promo codes are good for 5% off. Advance Auto Parts promo codes can get you up to 20% off depending on which promos they are running.

Wow! That sounds great. I will get a pair of them and put them on. Thanks for the reply. Only an hour , you make it sound too easy.

MA822; even less money (55) from Amazon, and free super saver shipping.

its the struts. my dads went bad, and so did mine. mine i let go so long it wore the inside of my tires bald lol. if you have the know how and tools to do them yourself its dirt cheap, me and my dad both got ours replaced at midas for $130 if i remember correctly. i dont really think its in reference to mileage, i think its just time. my dads car has under 70k and needed them, where mine didnt go bad till 110k. the rear shocks arent very good stock on these cars.

on a side note, midas put in Monroe shocks and they are noticeably stiffer than stock.

Bought the Monroe shjocks from Advanced Auto. They bolted right in just like the factory shocks. I found the best way to install them is to back the rear end up on ramps. There is no need to take the wheel off. Remove the nut on the top of the strut in the trunk, remove the bolt on the bottom of the strut and gently lower it down. Be carefull not to damage the air line. Pull the clip off the air line and it comes right off. When you put the new strut in attach the air line first then slide the top into position and install the nut in the trunk. Lastly install the two bolt at the bottom of the strut. Should not take much more than an hour. These struts ride just as nice as the origionals and you can't beat the price.

Thanks for the update glad you got er all up and running well riding smoothly