AOS replacement question.

Greetings all. I spend most of my time posting in the 928 forum, but actually have a 996 questions for once. My 2001 Cabriolet doesn't seem to cause me too much grief, so I don't post here often. I'm replacing my Air/Oil Separator with the engine in the car following the Pelican Parts instructions. I have everything up above removed down to all the hoses on top of the AOS, and have moved to beneath the car. Down below it's quite a tight fit and it's going to be daunting to get the bellows and the hose disconnected, but my question is this. I haven't even unbolted it yet, but from what I see, I'm wondering if it is easier to bring the AOS up and out the top of the motor once unbolted? It looks like there is more room up above than below, and seems with the electrical connector that is right next to the AOS, that it would go up easier than down. Has any one done this? Or does it only come out downward? Any tips and advice would be greatly appreciated. Thank you in advance 2001 996 Cab 6 Speed 1986.5 928S Auto

You can buy a special clip from pelican they are very cheap. . The clip is already in the open position until you have it in place, then you pull on the blue plastic clip and it releases the open clip to a closed position securing the bellows in place. It is in a very tight position as you say but I managed to get both hands in there but was only successful in releasing the bottom clip on the bellows. I had to thread a zip ti behind the top part and tighten with pliers. I changed my bellows after a so called mechanic installed a new AOS for me but failed to use a new bellows on the job. I believe if you change the bellows and AOS in one go, it is easier to attach the bellows to the AOS then insert the whole thing from the top and then pull on the bottom clip when the bellows is in place. You will need 2 blue plastic release clips to do the job correctly. Go underneath the car and release the old clip and bellow at the bottom. Then lift the AOS from the top out into your hand. Then release the bellows completely. Put the new bellows in place onto the aos and pull on the blue plastic. Then insert from the top into the open new clip, (the bottom one) do not pull on the plastic till you are absolutely sure that it is in place. Gently pull on the blue plastic and the clip should hold the bottom of the bellows securely in place. I hope you get the idea.

Just did this. It is easier to remove the old AOS from above once disconnected. You can also do three connections from above. I used a set of radiator clamp pliers for the billows, which basically does the same thing as the blue thing that Pelican sells (that does work well too). Also, if you do not have the manifold out yet, getting to the rear most bolt is much easier if you unbolt the AOS first.

Thanks for the tip guys. I just jacked it up a bit higher and am going to get under there and attempt it again. Yes, the back manifold bolt was the hardest, the other 5 were two minutes each. I lost the back bolt though, it fell inward and down onto what sounded like a metal cover. I'm going to try to find it when the AOS is out. I lost it before pulling the manifold, so it didn't go down the intake. It's probably on top of the tranny somewhere.

I just changed mine today. I have a 2002+ car so no bellows, makes removal somewhat easier. One tip I have for you...I found getting the rear (towards the rear of the car) allen bolt for the AOS back into place on the new AOS very difficult. I pulled the new AOS back up and put the allen bolt in place ahead of time, wrapped some electrical tape around the head and left a "tail" of tape I could grab once the AOS was in place. Then installed it back in place, pulled the tape and tightened down the bolts. It was nearly impossible to fit your fingers in there to get the rear allen bolt into the hole with the AOS in place. As far as access, definitely lower the engine as much as you can. I had my coolant tank out at the same time and that gave a little more room but still no easy job! Good luck!

Thanks again guys. I spent about 45 minutes under there today again and came away frustrated with nothing done. The squeeze fitting is near impossible, I can squeeze it, but have no leverage to try and uncouple it once squeezed. I'm going to try and use a zip tie to squeeze it and have my hand still free as one guy advised. The bellows is driving me crazy too, I can almost get the clamp squeezed with my angled needle nose, but can't budge it without losing grip on the clamp teeth. I'm considering cutting the bellows, which brings me to another question. It appears the AOS's on Pelican come with a new bellows attached. Is that the case, and if so, is it OK to cut the old one with a razor blade? Also, I saw those clamps with the blue clip attached. I'll be getting one of those. Also, I found the bolt from the rear intake manifold that I lost. It was down in a valley by the AOS.

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I'm working on a special plastic tool to replace the blue clip with something much easier but I doubt I'll have it finished before you scrape all the skin off your knuckles I took my AOS off from the reverse side with my gearbox out, so had other problems different from yours, I guess the old clip is real hard to remove from the trunk side.

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The AOS from Pelican does come with a new bellow. At least the two that I received in the last 4 months did.

That's good to hear. I can cut the bellows then if I can't get the clamp off. I think if it was cut and removed that I could get the lower bellows clamp off easier reaching from above with my long needle nose vise grip. That other squeeze to release clamp down below is even harder though. I can squeeze it, but it doesn't move. I'm going to try and spend an hour under there again tomorrow and try.

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These, or something like them would also be very helpful. They lock, so you can actually use both hands. Amazon Amazon

^^ I have that tool and it is one of the best tools to own. Makes working on the spring type clamps a breeze. Both of my sons have borrowed that repeatedly for engine work. Encouragement for the AOS job - it really is one of the most challenging jobs you will ever experience with the engine in the car. I remember it took me a grand total of about 4 days. If I recall correctly, cutting the bellows is what I did. Then loosened the AOS bolts and lifted the whole thing up in the engine bay to undo the other connections. I simply did not have the strength in my left hand to pinch to disconnect the AOS fitting. Getting it up allowed some flexibility and I could use my right hand to finally pinch the connector to undo, and pull it away with my left.

Thanks a million guys for all your help. My son (pictured below) and I got it out today. Some how his hands were able to pull the squeeze connector off while I used the long needle nose vise grips to compress the tabs. Then I used the same vise grip to hold the upper bellows clamp compressed, took the two bolts out, and the rest was history. I was surprised how easy it was to wiggle it up and out once lose. Took like 3 seconds. While I wait for my new parts to come, I think I'll use the old one to practice installing the new one a few times.

Glad to hear. If you have not already, make sure to plug the intake holes, and the bellows hole, and other connection point for the AOS with rags. Would be bad for something to drop down.

^ And remember to remove them prior to re-assembly. I almost made the fatal error while test refitting the intake tubes and rear plenum. Was almost ready to put the first bolt in and said DOH...forgot to remove the shop towels I stuffed in the intake holes. Think it through all the way.

I had the intake holes plugged, but hadn't thought about the bellows hole. Thanks. Randy