Bench test of airshock pump

[edwinn]

Hopefully can get a quick answer on this one.

I have the Air Shock pump removed from the lower Right Rear fender of the Riv sitting on the bench and would like to drive it with a 12 VDC power supply. Would that be ok? Observe polarity of the wires? There are two BLACK wires (one with green stripe) that connect to the motor. The green striped one looks like the HOT or +12V because the other BLACK is case grounded.

Here is a photo:




Also I'm going to make a custom air filter element for the intake. Will post that photo next.


It was waaay past time to service the Air Pump assembly!!


-Ed

[Blue Bowtie]

You should be able to test it with a power supply provided the supply has adequate wattage. I'm guessing the motor on the air compressor will draw about 7-10A, so make sure the 12V power supply is rated at at least 100W.

[edwinn]

Originally Posted by Blue Bowtie

You should be able to test it with a power supply provided the supply has adequate wattage. I'm guessing the motor on the air compressor will draw about 7-10A, so make sure the 12V power supply is rated at at least 100W.

Thanks man.. you were right. The power supply could only put out 3 Amps, so the pump barely tuned over. It did run but very slowly and seemed to exhaust a little air from the outputs. I may connect it to the vehicle HOT buss with clip-leads today however it could torque pretty hard when energized. Maybe not a good idea?

There was no question whether or not it worked.. just wanted to see HOW well it worked.


-Ed

[edwinn]

No Air Shock servicing mentioned in Owner's Manual

It's important to bring up this subject because NOWHERE in the owners manual is servicing the Air Shock system mentioned. I got into the RR quarter panel late last week and as usual, found a lot of deteriorated and broken components. Here are some views of the Air Pump system/assembly:










These photos were taken after I sponged down the area to remove DIRT and grime. Part of the "lower front-to-back inspection" task is rust control and removal. You can see a RED arrow pointing to the Air Filter Element plugged into the chassis in the above pic.


Below is a view of one of those Xmas tree wire fasteners that drove me nuts trying to release (not knowing it was there till the last minute.) The cover started to bend all to hell trying to pop-out the damn thing. I ended up cutting it short. If getting the rusted cover bolts out wasn't a PITA enough, the wire fastener took the cake! You can see how corroded and cruddy the cover plate was.





Painting the components

Here's a photo as of yesterday afternoon with the third coat of Rustoleum (rusty metal primer, flat black, and semi-gloss black) on the cover plate.






The pump was also touched-up with semi-gloss on some areas of rust. Below they are catching some HEAT out back this morning for some final drying time. Should be able to re-assemble today.





Air Filter Element

Some photos of the air filter unit. The top view against the beer bottle shows the inside of the filter tube and some residual glue used to hold the FOAM in place. THAT FOAM WAS SO DETERIORATED that is was a JOKE. Lucky the pump is still working ok!!





Today I should be able to pick out and CUT a piece of FOAM for the element





Air Intake Hoses

The Shop Manual says to `be careful when disconnection the filter hose´ because `dirt and debris can enter the system.´ Well that's another laugh because the hoses were so rotted that just squeezing them created a cloud of micro-fine rubber dust!! See the photo below of rubber crumbs on the driveway from simply placing the hoses down on it!!






You better replace these Hoses and the Filter foam right away in your Riviera!!


The new 1/4" Dia hoses will be cut and installed later today and put the rubber mounting grommets (also restored and juiced-up) back in place. Maybe get ambitious and install the whole assembly in the vehicle.


It's enjoyable to work on a project like this... and also FUN to post kool restoration and update photos!!


-Ed

[HotZ28]

I went through all this last year. Replaced all rotten "China" air hose and replaced intake filter with a 75 micron inline fuel filter. This gets rid of the foam insert, but can still use intake air from the inside frame rail. Click Here for an example. In addition, I disassembled the head of the compressor and removed all debris from the piston area and lubricated the cylinder with trans fluid. Works like a charm. BTW, you should test the compressor with full battery voltage and test output pressure. It should pump 60-80 psi when deadheaded.

[edwinn]

Originally Posted by HotZ28

I went through all this last year. Replaced all rotten "China" air hose and replaced intake filter with a 75 micron inline fuel filter. This gets rid of the foam insert, but can still use intake air from the inside frame rail. In addition, I disassembled the head of the compressor and removed all debris from the piston area and lubricated the cylinder with trans fluid. Works like a charm. BTW, you should test the compressor with full battery voltage and test output pressure. It should pump 60-80 psi when deadheaded.

Thanks.. a GREAT reply!! What vehicle did you do this to? Does the B&S filter take 1/4" hose? and how does it fit in the frame section? If you could explain more about the pump.. does it have gaskets and were they intact? How much debris was in there? Does the pump have oil? How is it kept lubricated? I didn't want to get inside the pump unless it was obviously broken.

The pump Assy in this discussion thread has been reinstalled in RR lower quarter panel. I'll post another reply to OP below. It was a tough "on your back" job but once the pump is out, you can re-fit the hoses easily.

Did I mention... THIS SYSTEM NEEDED ATTENTION 8 YEARS AGO.


-Ed

[edwinn]

Air Shocks done

The Air Pump is back in the vehicle now. The hardest part (beside reconditioning components) was driving around to buy parts and supplies. The first step was to cut NEW 1/4" vacuum hoses. Easy enough, and it's worth repeating: Get In There and replace those parts right away !!


View of the hoses




Turns out you don't need 15-1/2" on the Tee extension. I ended up cutting off 3-1/2", so make it a 12" section.


Pump Assy with rubber in place

Next was reinstalling the new 1/4" vacuum hoses and three rubber mounts (which were easy to recondition.. they cleaned-up real nice.) I juiced them good with Armor-All and they're in fine shape. The following view is the bottom side of the compressor.




Below is the top side of the Compressor Assy. The brackets that accept the grommets were touched-up with Rustoleum Semi-gloss sprayed into a paper cup and brushed on. The crankcase is aluminum with lots of white aluminum oxide on it. I may paint that satin black on the next servicing.. but was hesitant to paint the cooling fins just yet.





Air Filter Element

The last step before reinstalling was to cut a new FILTER element from polyfoam. The best method is to cut a chunk, then snip off corners lengthwise with really good kitchen sheers which slowly "rounds off" the piece into a plug and cuts it down to a suitable diameter.





Cut the foam plug to length and insert. It should be snug enough to stay in place while inside the chassis.




How often would you think the FOAM ELEMENT should be changed? or the in-line filter that Z describes?



Reinstalled

Here is the entire unit back in the vehicle with freshly painted cover.




Here's the BEFORE picture:




The air shocks were replaced 4 years ago, as were the tiny output air tubes. The dealer who did this job IMHO cut the far side' tube too short (see tube running off to the right in the photo above) so there wasn't enough slack to add a cable clamp which should attach to the NEW cover screw (see screw-head between the hoses near filter.) So I routed one tube behind the cover with tie-wrap to hold them both in place. Kinda' like having legs wrapped around you.

Three new metric cover screws were installed since the originals were rusted bad. Will be testing it out today or tomorrow. No fundamental problems are expected. Will have the system operationally checked soon.


-Ed

[HotZ28]

What vehicle did you do this to?

1996 PA Ultra

Does the B&S filter take 1/4" hose? and how does it fit in the frame section?

It was installed inline, using the existing frame intake, minus the foam. I used 100 psi compressed air to back flush the foam from the fitting, then connected the inline filter. I used 1/4 in gas hose, which in more durable & weather resistant than vacuum hose. Pics below show position inline.

If you could explain more about the pump.. does it have gaskets and were they intact?

The upper head gasket was flexible and reusable. You can not remove the cylinder, it is cast in one piece.

How much debris was in there?

Enough to concern me. I used compressed air to blow out the debris, then cleaned everything with WD40. Once the cylinder was clean, I added a small amount of trans fluid to the top of the piston & cylinder walls.

Does the pump have oil? How is it kept lubricated?

The compressor is an an oil free compressor. The piston appeared to be made from nylon, or Teflon. I was concerned about the lack of lubricate, and the debris causing damage to the piston ring, so hence the addition of a thin layer of trans fluid. With the cleaning & lube, the compressor jumped from 25 psig to 65 psig when tested deadheaded.

BTW, Click Here for a parts list. Notice, parts number that are not shown, are no longer available from any GM dealer. The piston ring is one of the parts not available.

[HotZ28]

I also installed an air pressure gauge in the trunk, along with a manual air fill (schrader valve) to allow pumping the struts up with an external compressor, in the event the compressor should ever fail again. Notice, ideal pressure for my particular vehicle happens to be 18-20 psi, which maintains correct ride height and does not over burden the front struts.



I happened to find a pic of the filters I purchased @ AZ for the installation. I used the one on the left for the compressor intake & the one on the right for my riding lawnmower fuel filter.

[edwinn]

Originally Posted by HotZ28

I also installed an air pressure gauge in the trunk, along with a manual air fill (schrader valve) to allow pumping the struts up with an external compressor, in the event the compressor should ever fail again. Notice, ideal pressure for my particular vehicle happens to be 18-20 psi, which maintains correct ride height and does not over burden the front struts.

Great stuff Z!!

Frank had airshocks in his 1970 Formula 400 with a filler valve mounted beside the rear license plate. It could be jacked-up any time, to any height. That was back in high school days. Frank worked at a Delco wholesaler (as did his dad) and taught me a LOT about keeping GM cars in shape.

The dealer checked my load-lever system and said it was working correctly, but I question how thorough of a job they did.. probably didn't measure pump/air pressure. The adviser said they were going to put a LOAD in the trunk and check it.

I'd like to remove the air pump aGaiN maybe this winter or next year and do they cylinder head servicing that you describe, but don't understand deadhead pressure.. is that into a closed tube/gauge? Also I have no pressure gauges or fittings. The head removal is described in detail in the Service Manual.. even the head bolt torque. Might be PM'ing you on this subject.

Also.. I think the foam air filter element would work ok as long as it's kept from deteriorating. The Parts Dept printed out a diagram when I ordered new 'tube clips' that shows a LONG foam element protruding ~3/8" from the filter housing. See Item #6 in diagram posted by HotZ28 below.


-Ed

[HotZ28]

Your air dryer discharge (dual) is a little different than mine, which has a single outlet with a "T" in the line feeding the struts. You can still use a test gauge if you remove the air connector from the dryer and block one port, while testing the other. You can use a rubber tipped air blow gun with an air gauge adapted, and insert into one of the dryer discharge ports. You can use your finger to block the other port, then test psi. Click here for an inexpensive test gauge.

[HotZ28]

[edwinn]

Originally Posted by HotZ28

Your air dryer discharge (dual) is a little different than mine, which has a single outlet with a "T" in the line feeding the struts. You can still use a test gauge if you remove the air connector from the dryer and block one port, while testing the other. You can use a rubber tipped air blow gun with an air gauge adapted, and insert into one of the dryer discharge port. You can use your finger to block the other port, then test psi. Click here for an inexpensive test gauge.

Thanks Z,

Where did you order the valve and gauge from? I looked in www.grainger.com yesterday and will check www.mcmaster.com

Where are your valve and gauge mounted? .. in the floor of the trunk?

The dual discharge fitting could be a problem. Combine into a single air line? If the system fails someday, I'll go with the setup Frank had (similar to yours) on his Formula 400.


-Ed

[HotZ28]

Originally Posted by edwinn

Thanks Z,

Where did you order the valve and gauge from? I looked in www.grainger.com yesterday and will check www.mcmaster.com

Where are your valve and gauge mounted? .. in the floor of the trunk?

The dual discharge fitting could be a problem. Combine into a single air line? If the system fails someday, I'll go with the setup Frank had (similar to yours) on his Formula 400.


-Ed

I happened to work for a place that is a distributor for pneumatic valves, gauges, tubing & fittings and a lot of other parts. I had no problem finding what I need in inventory. The gauge/fill valve assembly, I built myself, with parts available in stock. I mounted the gauge in the upper trunk area, below the rear window. 1996 PA Ultra.