74 Eldorado Rear Shocks

[danjarrett1]

Gentlemen: at present, I have a set of air shocks on my car  that I inherited. I'm considering replacing them with new as they are getting weak. I have used KPG shocks in the past, question: should I reinstall air shocks or just go with conventional rear shock? The factory or suspension system was deleted years ago I presume.. given the circumstances, what would you go with?

[TJ Hopland]

The air shocks were standard equipment for the Eldos in this era so the factory springs even when new were on the weak side to work in conjunction with the air shocks so without the help of the air the rear will sit low to very low depending on how much gas you have in the tank and if you put any cargo in the trunk or people in the back seat you could darn near end up dragging the bumper on the ground.

I think there were some years where Toronado didn't have air standard so it was possible to order the standard springs and shocks for a non air car and get a reasonable ride height without air shocks. Many years ago when I was annoyed at the system I think I did some checking and wasn't able to find anything listed anymore so if you don't have those stronger springs now you may have to do your own research to figure out which springs to buy.  I don't think they are that unique so I'm sure there are other full size GM cars that used the same size and height springs. I have also wondered about the air bags you stuff into the springs but again you would be on your own trying to figure out which size to get.

As far as the air shocks they are still available but I have a theory that they have not been made in many years so we are working off existing old stock.  Also doesn't seem to matter what brand you order you will get the same black shock that may or may not even have a brand label on the box so who ever made the last batch made em for everyone.  When they are still working the ride is fine but I have had terrible luck with them lasting.  I have quit replacing them in pairs and now just replace the one that is leaking oil and keep the other on the shelf for the next failure. 

My compressor has never worked since I bought the car 30+ years ago now.  There was a manual tire valve fill when I got it and that is still the setup I have.  I don't find that I have to adjust it very often.  I usually run it at the max my garage compressor goes to which is around 125 I think.  I usually top it off in the spring and its good all summer. I have thought about going to an electric compressor but I just don't have to adjust it often enough to make it worth the trouble.   

These still used a vacuum powered air compressor under the hood to build the air pressure.  The system worked just like a compressor in your garage and had a small tank.  When the 'power' is on which in this case is engine vacuum the compressor maintains the tank at a preset pressure.  There is then an air line running to a mechanical valve attached to the rear axle.  If the rear is high the valve opens a bleed port and lets some air out to lower the car.  IF its low it opens the line to the compressor and the car raises.  There is a oil filled dashpot in the valve that creates a slight delay so it doesn't try to adjust as you go over bumps and such.

If your valve was still good in theory you could just get a little 12v compressor that has a tank and auto fills and shuts off just like one you would have in your garage and the system would work as designed.   If you went with a compressor like the factory went to in 78 you would need to rig up a manual switch to add air or bleed air so it would not be auto.  The electronic height sensor control modules the factory used were not especially reliable as they aged and were not ever made or repaired by aftermarket as far as I know.

[danjarrett1]

Thank you TJ, I have no desire to return the car to factory specs regarding the it compressor and such, I'm fine with air shocks that are filled through a central line manually. Just wondering in Monroe is better than others, or are there better options ?

[The Tassie Devil(le)]

I have Monroe Air Shocks in the back of my '72 eldo, and have fitted a manual filling point at the rear left side of the frame, facing back towards the bumper bar, and whenever it loses air, I use mt compressor and refill it to around 75 psi.

I also have a 12 Volt Monroe compressor which I have been tinkering with putting it up front in place of the original Vacuum Pump, but still trying to get that to operate correctly.

Bruce.