Cheap Fix for Broken Air Suspension Compressor Silencer

[IPreferDIY]

Here’s a cheap fix for the air suspension compressor silencer. Mine didn’t survive when removing the fender liners to replace the upper control arm bushings on my 2000 Grand Marquis LS. (More on that later.)

My local Ford dealer said the silencers were no longer available, though I would think the ones from later years are the same. In any event, I wanted something sturdier than what came out.

I had already replaced the gaskets and bolts/nuts where the catalytic converters attach to the H-pipe. (Ford uses regular bolts/nuts on a stainless steel exhaust? WTF?!?) I had used 3/8" stainless steel bolts/nuts/washers that my father had left over from his machine shop days, and I still had some left over. The holes for the air compressor in the fender liner are actually 3/8", so I was halfway there.

I checked the websites of my local hardware stores for anything made of rubber, and one of the things that came up was rubber parts to protect floors from furniture. I found some 7/8" screw-on rubber bumpers whose narrow end just barely fits in the holes on the compressor mount where the black silencer bushings go. I just had to enlarge the holes to 3/8". I also found some 1 3/4" round rubber cups (for protecting your floor from furniture legs) that had a ridge that was just the right size for pushing down on the mount. I just had to drill 3/8" holes and cut away the excess using a series of 1/16" drill holes and a knife. For the top washers, I cut the threads off of plastic caps from juice containers. The reinforcement on the outer edge of the resulting plastic washer is useful for focussing the downward pressure in that area.

A photo of these parts is attached.

This was my setup, starting from the bottom:
• 3/8" stainless steel bolt, pointing up
• ‘flat’ spring washer with wide end against fender liner (I had run out of regular flat washers)
• fender liner
• white rubber bumper, narrow end up
• air compressor mount sitting on narrow end of white rubber bumper
• piece cut from round rubber cup to push down on mount
• plastic washer made from juice cap
• flat metal washer
• regular nut

The compressor is so noisy that you can’t do much to ‘silence’ it, but this setup provides some degree of improvement over the original silencer.

I just relied on the force of the rubber to keep the nuts in place, so if the nuts loosen off, I guess I’ll add some thread lock or use the nuts with the nylon inserts.

It ain’t pretty, but it’s cheap and it works!

[gadget73]

When you say silencer, do you mean the rubber mounting grommets that keep the compressor from buzzing like crazy against the bracket? I don't really know what they did with compressors on later years but I know the 80s and early 90's stuff had rubber motor mount grommets that fell apart and got noisy. They were available from Arnott or Strutmaster or one of those places though.

[IPreferDIY]

I was referring to the whole assembly with the bracket, but I'm no expert. The fordparts.com website lists a "Suspension Air Compressor Silencer Kit" with part number 5Z205 for $68.13US, and this includes the bracket with the bolts as well as the rubber things, but my local Ford dealer said they couldn't even get one from the U.S. There was (and apparently still is) a listing on eBay for a "2003-2005 Crown Victoria Air Compressor Silencer Kit Ford F6AZ-5Z205-AA", item number 360615790989, for $19.95US, but shipping to Canada would have brought the total to well over $40US. I saw just the rubber things listed on the arnottcanada.com website as "New Vibration Isolator Kit K-2103" for $19.95US, but two of the bolts on my mounting bracket were broken, so I was not in a position to replace just the isolators. In the end, I paid less than $10CDN for the rubber parts that I used, and I'm much happier than I would have been if I had just used stock parts.

[gadget73]

hm, interesting. I didn't know there was a numbered kit that included the bracket. Hey, if you got it to shut up for small money and its effective, then good job says I !

[LithiumCobalt]

I haven't looked at my '87 closely enough to see how it vents, especially since the level sensor is shot right now and the system is useless anyway, but I do recall on my 96 Town Cars, a black box mounted behind the left headlight assembly that was connected to the compressor vent solenoid via a short section of rubber house. I believe this was a type of silencer. You could barely hear the venting occurring. Replacement air compressors from Arnott and the like simply had a "pourous rock" at the vent solenoid rather than a port to hookup the rubber hose to the factory silencer. Venting was much quicker and much louder with that setup. It's true you can still buy the rubber isolators through Arnott for about $20/set.

[gadget73]

the 86 compressor had a connection to a rubber hose that went out to the back of the car. When they moved it up front in 87, it vented right out of the side of the compressor. I currently have a hybrid 86/87 compressor in my car. Mounts from the 86 to fit it in the trunk, but the compressor head assembly is from an 87 to let it use that style of drier since the 86 part broke and is a one-year part. It hasnt been in use for a while. Whenever I get motivated to put the air suspension on the car, it'll be running 1990s parts, probably with the compressor up front and all like those cars ran. I have the later inner fender already, so its got the compressor mounting hole.

[IPreferDIY]

That little black box was a mystery to me before I saw your post, Nick. An as-yet unsolved mystery is the big square box on top of the driver's side fender liner, the one that the relay box attaches to. The big square box only has a rubber hose going to it, and the other end seems to be connected to the vacuum system. Any idea what the big square box is for?

[gadget73]

Its the vacuum reservoir for the climate control system.

[IPreferDIY]

That's a new one for me. Apart from the heater core, I haven't had to mess around with that stuff yet. Thanks muchly!

[IPreferDIY]

Here's a link to my dryer desiccant renewal thread:

http://www.grandmarq.net/vb/showthread.php?53206-Rehabbing-the-Rear-Air-Suspension-Compressor-Dryer&highlight=

and here's a pic showing my current anti-vibration setup, which is secured with nylon lock nuts:



When I put the compressor in last time, the plastic fender liner was out of the car, and I hadn't given any thought to how things would go with the liner in place. It turns out that it's better to have the bolts pointing down. The holes in the white cone parts are small enough to hold the bolts tightly, which makes things easier. You still have to take out the two front fender liner bolts and the two bolts near the top of the wheel well to get enough movement out of the liner to get the compressor out and in. To get a wrench on the bolt under the dryer, I had to slide the connector off its bracket. Hopefully I won't have to mess with it for at least five years, which is about how long I'm figuring the desiccant will last before needing to be dried out again.