air shock pressure

Tim Prieur

PCS Member
Could someone guide me as to the proper inflation pressure on the rear air shocks in a 75-6 Superior Caddy high top? (At present it is zero). Before I start trying to inflate anything, best to ask.

Thanks in advance.
 
Well it all depends on the rear height & ride you want. My '66 Superior hightop looks & rides best at 80 - 100psi. On the S&S hearse I run the same but that's to compensate for how high it sits in the front, rides a little stiff in the back on a much lighter coach but like the look.

If you have a lot of line leaks/cracks like my ambo did, buy an air shock line kit (they are only about $13 complete) & install new lines, o-rings, & filler valve.
 
Well it all depends on the rear height & ride you want. My '66 Superior hightop looks & rides best at 80 - 100psi. On the S&S hearse I run the same but that's to compensate for how high it sits in the front, rides a little stiff in the back on a much lighter coach but like the look.

If you have a lot of line leaks/cracks like my ambo did, buy an air shock line kit (they are only about $13 complete) & install new lines, o-rings, & filler valve.

I agree with Dwayne and he should know. Depends on car but at least 50psi just so the shocks work at all and go up from there to get desired ride and height.
 
If you run the car with no air pressure in the shocks, you will cause damage to the rubber boots of the shocks and then they will not hold air in the future. I never worry about the pressure, but inflate them to the point where the rear is level with the front. Every car will be different..
 
Here's some shots for comparison...
IMG_0647.jpg

This was how it sat when I got it... all the air shock lines were blown out & brittle when it was driven home, and it handled awful & tipsy with zero air in the shocks.

IMG_0700.jpg

After all new air shock line kit installed (and new wheels/tires) and pumped up to 100psi. Notice center of rear mag wheel compared to stocker hubcap... no change in rear height but the handling & ride are improved VERY much, it corners much better & just feels better on the highway.

Now for the S&S... stock height looked AWFUL. Commercial chassis springs boost the front end WAY up so it was always hunkered down in the back. This is how it looked the day I arrived from Florida with it...
3389398080_40a2778737_z.jpg


The load leveling compressor was locked up so I bought an air line kit just for the filler valve. These load leveling systems are complicated & stock shocks had 2 lines each instead of one. I know how it's all supposed to work but won't bore you with the micro-switch controlled leveling system. Disconnecting the seized-up pump & removing the single line... I capped one side of the "tee" manual filler valve & the other to this single line. Now I have a manual valve under the hood for filling my shocks to how I want it to sit while still utilizing the stock shocks...
3388579831_5a0556f037_z.jpg


It don't ride like it should, but I went for a mild aggressive look with this coach & wanted a slight rake without cutting the front coils. Took the time tonight to explain this because several of you had complimented me these last 2 years of owning this one that you liked the stance & wanted to know how to do it. It's a bit stiff in the back but the ride isn't uncomfortable.
 
Commercial Chassis cars sit lower in the front than the rear when they left the factory, since they would level out once you put a load into them. I had new exact replacement springs made for my 1969 Miller Meteor ambulance and replaced all the front suspension parts with new last fall. Now, the car has a noticeable rake to it and I almost wish that I had the front springs raised about an inch so the car would sit more closely to level. I don't think it will ever have enough weight in the rear to balance out.
 
Here's some shots for comparison...
IMG_0647.jpg

This was how it sat when I got it... all the air shock lines were blown out & brittle when it was driven home, and it handled awful & tipsy with zero air in the shocks.

IMG_0700.jpg

After all new air shock line kit installed (and new wheels/tires) and pumped up to 100psi. Notice center of rear mag wheel compared to stocker hubcap... no change in rear height but the handling & ride are improved VERY much, it corners much better & just feels better on the highway.

Now for the S&S... stock height looked AWFUL. Commercial chassis springs boost the front end WAY up so it was always hunkered down in the back. This is how it looked the day I arrived from Florida with it...
3389398080_40a2778737_z.jpg


The load leveling compressor was locked up so I bought an air line kit just for the filler valve. These load leveling systems are complicated & stock shocks had 2 lines each instead of one. I know how it's all supposed to work but won't bore you with the micro-switch controlled leveling system. Disconnecting the seized-up pump & removing the single line... I capped one side of the "tee" manual filler valve & the other to this single line. Now I have a manual valve under the hood for filling my shocks to how I want it to sit while still utilizing the stock shocks...
3388579831_5a0556f037_z.jpg


It don't ride like it should, but I went for a mild aggressive look with this coach & wanted a slight rake without cutting the front coils. Took the time tonight to explain this because several of you had complimented me these last 2 years of owning this one that you liked the stance & wanted to know how to do it. It's a bit stiff in the back but the ride isn't uncomfortable.

The stiffs are SUPPOSED to be in the back!....(sorry, I couldnt let that one pass me by)
 
they put the air shock on so that one could balance the ride height with the load. so as suggested you need to put as much air in the system as it takes to bring the car level. the auto system was adjustable for the ride height also. the big problem with them in both the ford and GM line is there expense in replacement parts. none of us are using the car for what it was designed for any more. so we have to father adjust to what we are doing. most of the handling is from the rear suspension. to weak back there and the car will not handle at all. ever notice that as you fill the rear shock the front of the car will come up to?
 
Thanks for all of the input. After 60lb (to start) the two cars no longer feel like I am on the ocean buffeting 6 ft waves.
 
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