When to Let Your PA Go??

[fm9572]

The air suspension isn't designed to last 166k. If you want me to go through the entire class for you, I can. It's a decision on what you want. If you want to keep it 'original' and have load leveling capability, you need to replace everything as a set. If you just want to be able to drive it, and never have to worry about replacing expensive air suspension parts, then you need to convert it to a 'conventional' system.

To begin;

The GM air suspension system on most vehicles consists of; an air compressor, two air shocks, and depending on how 'advanced' it is, a computer for Cadillacs, and a (or 2 with the Cadillac computer) height sensor.

The Shock absorbers have rubber air bladders on them that dry rot with age, causing pin hole leaks. when the shocks start leaking, it's like trying to blow up a balloon with a hole in it. The air leaks out, the height drops, and the compressor kicks on. Eventually, the compressor stays on, trying to fill the leaks. If it runs past a certain time, the relay overheats, and cuts power to the compressor, turning it off. When the relay cools down, power resumes to the compressor, and it runs until it overheats again. The compressor was designed to only run for under a minute or less, just to top off the system. Running constantly like this ruins the compressor. That's why if you 'fix' the air system, it's recommended you replace the shocks and the compressor as a set.

I used to work for a company that replaced the air shocks with a set of conventional shocks, replaced the 'low rate' coil springs (they actually take about 70% of the load, allowing the shocks to adjust for the rest of the load, partly so they didn't have to have huge air springs holding the car up, and partly so when the air system failed, it was still driveable) with a set of "normal rate' springs, and instructions for disabling the compressor. The car rides at 'normal' ride height, handles normally, and unless you load the trunk up, can carry the factory recommended weight rating.

The company I used to work for (Strutmasters) has the conversion kits for sale. http://www.strutmasters.com/Buick-Park-Avenue-Air-Suspension-Conversion-Kit-p/-gmlb-r1-bpa.htm

There is a 'cheapo' version that Monroe came out with, that most companies were selling for quite a while that lifts the car up, but has several problems. It's basically a set of "truck overload shocks" that are a set of shocks that have a set of coil springs on them, instead of the air bladders. they will 'absorb weight,' but they aren't tuned for the factory suspension, so they tend to make the rear set up like a top fuel dragster, unless you have a ton of weight in the car you plan to carry around constantly (like a massive sound system). All of the major companies have versions of these shocks. They're cheap, and they ride like crap. Also, because they 'sit up,' they don't allow the rear suspension to sit at 'normal' ride height,' so it can't be aligned properly on an alignment machine.

There are companies that sell REPLACEMENT air parts, like Suncore and Arnott. They will sell parts separately, but they will only warranty parts if you buy everything as a set. The parts they sell are made in China. I know because they were the supplier for the air shocks that Strutmasters used to sell, and the case we got them in had Chinese markings all over it. If you plan on going with the factory air system, then I would buy a compressor from them, and get a set of KYB replacement air shocks.

The KYB shocks are part number SR1002, and the top mounts are SM5334. Arnott sells the compressor on Amazon, and the supplier for the KYB shocks and mounts sells on Amazon as well.

As far as that goes, the Strutmasters kit is sold on Amazon, too. It's just a few dollars difference than direct from the manufacturer, and they're better about tech help if you buy direct from the company, so they don't have to give Amazon a commission.

Like I said, it all comes down to what you want."Factory OEM ride and functionality," or "a smooth, well handling ride, with conventional system reliability." If you go with the air, it's more expensive to do it properly. If you go with the "conventional system," it's more reliable, less expensive, and will never have a compressor run your battery down, or have a sagging, poor handling rear suspension. Your choice.

 

[01PA]

The air suspension isn't designed to last 166k. If you want me to go through the entire class for you, I can. It's a decision on what you want. If you want to keep it 'original' and have load leveling capability, you need to replace everything as a set. If you just want to be able to drive it, and never have to worry about replacing expensive air suspension parts, then you need to convert it to a 'conventional' system.

To begin;

The GM air suspension system on most vehicles consists of; an air compressor, two air shocks, and depending on how 'advanced' it is, a computer for Cadillacs, and a (or 2 with the Cadillac computer) height sensor.

The Shock absorbers have rubber air bladders on them that dry rot with age, causing pin hole leaks. when the shocks start leaking, it's like trying to blow up a balloon with a hole in it. The air leaks out, the height drops, and the compressor kicks on. Eventually, the compressor stays on, trying to fill the leaks. If it runs past a certain time, the relay overheats, and cuts power to the compressor, turning it off. When the relay cools down, power resumes to the compressor, and it runs until it overheats again. The compressor was designed to only run for under a minute or less, just to top off the system. Running constantly like this ruins the compressor. That's why if you 'fix' the air system, it's recommended you replace the shocks and the compressor as a set.

I used to work for a company that replaced the air shocks with a set of conventional shocks, replaced the 'low rate' coil springs (they actually take about 70% of the load, allowing the shocks to adjust for the rest of the load, partly so they didn't have to have huge air springs holding the car up, and partly so when the air system failed, it was still driveable) with a set of "normal rate' springs, and instructions for disabling the compressor. The car rides at 'normal' ride height, handles normally, and unless you load the trunk up, can carry the factory recommended weight rating.

The company I used to work for (Strutmasters) has the conversion kits for sale. http://www.strutmasters.com/Buick-Park-Avenue-Air-Suspension-Conversion-Kit-p/-gmlb-r1-bpa.htm

There is a 'cheapo' version that Monroe came out with, that most companies were selling for quite a while that lifts the car up, but has several problems. It's basically a set of "truck overload shocks" that are a set of shocks that have a set of coil springs on them, instead of the air bladders. they will 'absorb weight,' but they aren't tuned for the factory suspension, so they tend to make the rear set up like a top fuel dragster, unless you have a ton of weight in the car you plan to carry around constantly (like a massive sound system). All of the major companies have versions of these shocks. They're cheap, and they ride like crap. Also, because they 'sit up,' they don't allow the rear suspension to sit at 'normal' ride height,' so it can't be aligned properly on an alignment machine.

There are companies that sell REPLACEMENT air parts, like Suncore and Arnott. They will sell parts separately, but they will only warranty parts if you buy everything as a set. The parts they sell are made in China. I know because they were the supplier for the air shocks that Strutmasters used to sell, and the case we got them in had Chinese markings all over it. If you plan on going with the factory air system, then I would buy a compressor from them, and get a set of KYB replacement air shocks.

The KYB shocks are part number SR1002, and the top mounts are SM5334. Arnott sells the compressor on Amazon, and the supplier for the KYB shocks and mounts sells on Amazon as well.

As far as that goes, the Strutmasters kit is sold on Amazon, too. It's just a few dollars difference than direct from the manufacturer, and they're better about tech help if you buy direct from the company, so they don't have to give Amazon a commission.

Like I said, it all comes down to what you want."Factory OEM ride and functionality," or "a smooth, well handling ride, with conventional system reliability." If you go with the air, it's more expensive to do it properly. If you go with the "conventional system," it's more reliable, less expensive, and will never have a compressor run your battery down, or have a sagging, poor handling rear suspension. Your choice.

Beautiful. Just beautiful. Thank you for that info!!!! 😀 I wish I had known all of that a while ago, when I bought new air shocks for the car when I was told they were bad. So I have new air shocks and the old compressor and all that. I'd like to convert one day.....guess once my compressor goes out fully. It takes much longer than a minute for it to run. Usually four, maybe five. 😕

 

[Kevandkaye]

When my shocks went bad a few years back, I just put a fill valve in the trunk, teed off to the new shocks and pulled the compressor relay. I wanted to eliminate any future problems right then....

 

[93PA]

So I took my car to get an oil change and they looked my car over as well because my car wouldn't start a week before the oil change and all of a sudden did. Here's what they found wrong with my car:

1. Need new upper and lower radiator hoses.
2. Need new struts
3. Need rear toe links
4. Need new fuel pump (Why the car didn't start)
5. Need new drive axels (leaking grease/sludge up front on brakes and front suspension stuff)

Other stuff:
1. Coolant flush
2. Transmission flush
3. Possible battery

Now, I went to NTB to get the oil change and the total for everything was $2,679. Of course, I'm NOT PAYING THAT. The guy was making conversation and told me that he wouldn't put any money into the car because it's just not worth it, he felt, as more would keep going wrong and the prices will increase, especially for a PA. My car has some rust issues he said and it being a 2001 with 166k miles, stuff is gonna go wrong and I know that.

I don't feel the things it needs are major things like the car should be dumped, but I wondered why he said that. I was just putting that out there to see what you guys may think.

I looked up the value of my car and it's worth about $1300 according to Edmunds. I bought it this june for $2100.

I put about $1000 into it since then to replace the brake lines that went out, the brake calipers and bleeders that broke and the rear air shocks that went out as well.

Still, it's not time for it to leave, exactly, is it?
Here's some pics:

Was at a Firestone shop years ago. Guy came up with all of these reasons the car was in bad shape and maybe not worth putting $ into it. But his brother liked these types of cars and might take it off my hands if I was ready to junk it. Well, car still with me 5 years later and I never darkened his door again.

 

[01PA]

When my shocks went bad a few years back, I just put a fill valve in the trunk, teed off to the new shocks and pulled the compressor relay. I wanted to eliminate any future problems right then....

I heard about pulling the compressor relay. If I pulled mine now (it works, kinda) would I have any problems? Would the car sag or raise up high? Also, where is it, just for future reference?

Was at a Firestone shop years ago. Guy came up with all of these reasons the car was in bad shape and maybe not worth putting $ into it. But his brother liked these types of cars and might take it off my hands if I was ready to junk it. Well, car still with me 5 years later and I never darkened his door again.

I'm trying to get to that level. One step at a time.....

 

[Spriteman]

On the I/P Fuse Block - ELC 10 Amp - Hot in Run

On the rear Fuse Block - ELC Circuit Breaker 30 Amp - Always Hot

The ELC relay is also on the rear fuse block.

 

[01PA]

On the I/P Fuse Block - ELC 10 Amp - Hot in Run

On the rear Fuse Block - ELC Circuit Breaker 30 Amp - Always Hot

The ELC relay is also on the rear fuse block.

Thanks!

Anyone know if these are good?
http://www.ebay.com/itm/Buick-Quick-Complete-Front-Strut-Spring-Assembly-Pair-I-Riviera-Park-Avenue-/280993852330?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2001%7CModel%3APark+Avenue&hash=item416c89ebaa&vxp=mtr

 

[Kevandkaye]

Thanks!

Anyone know if these are good?
http://www.ebay.com/itm/Buick-Quick-Complete-Front-Strut-Spring-Assembly-Pair-I-Riviera-Park-Avenue-/280993852330?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2001%7CModel%3APark+Avenue&hash=item416c89ebaa&vxp=mtr

Never heard of those. KYB are pretty highly rated and priced cheaply for our P.A.'s. I don't think you'd want to prematurely pull the compressor relay as long as it's working. You may end up with a pretty flat rear ride!

 

[01PA]

Never heard of those. KYB are pretty highly rated and priced cheaply for our P.A.'s. I don't think you'd want to prematurely pull the compressor relay as long as it's working. You may end up with a pretty flat rear ride!

Ahhh. Okay. Thank you!

 

[fm9572]

The air shocks account for about 1/3 of your rear suspension spring rate in normal operating conditions, so just "pulling the relay," is a pretty bad idea. The air bladders are made of rubber, and if they're already leaking, that means they'll be empty, which means they aren't working. Even if they're 'new' the air will eventually leak out, meaning that the 'soft' rear coil springs are the only thing holding the rear suspension up. It will ride like crap, and the rear will always look like you have a heavy load in the back of it.

"Capping the lines' only works with fairly new, functioning rear air shocks.

You can do whatever you want, but, 'rigging stuff up' usually comes back to bite you in the butt, usually sooner than later. Just my 2 cents.

 

[Cadillac_AL]

I didn't look at this thread because I assumed we were talking about junking worn out cars. The ELC system has been around for over 30 years and is not a complicated system. I hate to see threads about bypassing it for an old fashioned rough rider suspension. Replacement struts are reasonable and the compressors last a long time unless you don't replace your struts when needed and let the compressor burn out.

My 78 Seville still has a working compressor and level sensor although a previous owner bypassed it with a Shcraeder valve. I haven't bothered putting it back to original because my load never changes on this car.

On these newer Park Aves just replace the rear struts every 10 years and you will never have a problem.

 

[pila80]

On my old Caddy beater, I replaced all the struts, but used a valve & lines in place of the ELC stuff, and saved the compressor as a spare for the Buick !

 

[fm9572]

For the record, my 1994 was used by the company I used to work for to develop the replacement kit they sold for the rear suspension. It isn't a "rough rider." My car rides just fine, and probably will out handle most Park Avenues of it's era on the road. The only difference is that it doesn't have the "load leveling" capabilities that the air suspension gave it. I have put over 20k miles on it since the suspension was changed, and it hasn't given me a bit of problems.

If you want to leave your suspension stock, that's all well and good. I respect that. Many people like to keep their vehicles as OEM as possible. But please don't trash my car and call it a "rough rider" because I chose to no longer use the air suspension. I used a well engineered kit, that was tested and designed for the vehicle and installed by professional suspension experts. I didn't rig some crap up.

 

[Kevandkaye]

I didn't look at this thread because I assumed we were talking about junking worn out cars. The ELC system has been around for over 30 years and is not a complicated system. I hate to see threads about bypassing it for an old fashioned rough rider suspension. Replacement struts are reasonable and the compressors last a long time unless you don't replace your struts when needed and let the compressor burn out.

My 78 Seville still has a working compressor and level sensor although a previous owner bypassed it with a Shcraeder valve. I haven't bothered putting it back to original because my load never changes on this car.

On these newer Park Aves just replace the rear struts every 10 years and you will never have a problem.

I have to side with the others on this post. Just replacing the shocks on these newer systems does not always solve the problem. They have been known to blow compressor and pump seals, motors go bad too. You must also consider location and mileage into the equation. I live in Northern Indiana and the winters and salt are definitely NOT kind to any under body parts! My shocks were leaking when I bought mine, but for what my intentions were, and the self leveling factor, It wouldn't pay for me to repair the system only to have it level me down every time I wanted to air up for race days....

 

[01PA]

Lots of great info and ideas in here guys!!! Thank you!!!
I'm gonna keep the relay and compressor and all of that connected and just go from there. I replaced the air shocks a while ago, so once they all go out (hopefully not soon), I'll look into a conversion kit. I think that would be a good way to go...I see compressors alone are $200 or so.

Glad I came on here. When I bought the car in June, I honestly had no idea what my $2,100 was buying me. I just knew it was better than the 95 Grand Marquis I had and was better on gas too. 🙂

 

[Spriteman]

If you're sure that it's a bad air compressor and you're trying to get by for now - see if you can find a used one online via ebay or even at your local salvage yard. It might not be a long term solution but it might get you through a year or it could be good for 10.

If you've already replaced the air shocks then the pump shouldn't have to work that hard.

 

[01PA]

I believe it's the air compressor. I can hear it when I start the car up and about five minutes later, it cuts off....or what I think is cutting off.

 

[Spriteman]

If you hear the compressor running I would check to make sure whether it's the compressor or some other component.

You could pull one of the hoses in the system at the compressor and see if you're getting any air pressure coming out while it's pumping. If you do then it looks like it's not the compressor. Maybe you have a leaking hose that's not allowing the pressurized air to get to the air shock.

If you're not getting any pressure at the compressor then it sounds like it's bad - maybe you could open it up and find where it's failing.

There are a few other components in the system like a dryer, a distribution system manifold - IIRC.

Here's a link to a good diagram that shows the different parts - http://parts.nalleygmc.com/showAssembly.aspx?ukey_assembly=369006&ukey_make=1022&ukey_model=14446&modelYear=2001&ukey_category=19409&ukey_trimLevel=15566 It looks like it's fairly serviceable.

PS I don't know if this is your exact system - you'll have to do a lookup with your VIN and make sure.

 

[HotZ28]

If the compressor is failing, it may only pump a small amount of pressure and not enough to meet the level control requirements. It takes about 16-20 psi to maintain level. Every time you turn on the ignition you should here the compressor run for about 5-sec. Once this event this takes place, if the rear is sitting too high, the exhaust valve should open & relive pressure to obtain correct level height. The only way to test the compressor psi capability, is with a pressure gauge. Normally, the compressor should pump 60-psi with a gauge connected. Feeling air blowing from the compressor, is not a valid test of the compressors pumping capability. Been there, done that many times.

 

[fm9572]

Compressors don't just run on their own. If it's running more than about a minute, then there's a LEAK. Think of trying to blow up a balloon with a hole in it. Eventually, your cheeks wear out. If you just slap another compressor in it (used or new) it's just going to do the exact same thing if you don't stop the leak.

If you changed the air shocks, and didn't change the compressor, Like HotZ28 said, the compressor was probably already damaged by the leaking shocks that were already on it. The piston in the compressor has a Teflon seal (piston ring) that once it gets hot and wears out, doesn't seal any longer. The compressor can run all day long in that situation, and not make any compression.

Would you change a water pump, or alternator, and not change the belt? If you don't do it all as a set, you're just spinning your wheels.