Succesful Aux Air Valve Repair on M110.983 engine

[wacotech]

Succesful Aux Air Valve Repair M110.983 engine.

Hello all, i have been reading here for a few weeks since becoming a proud new owner of a euro 1975 280SE.

Car had been standing for 10 years a few years back, so the AAV was stuck open. Tried soaking in benzine no help.

It's this version:


In the end i cut through the top edge/corner with fine hack saw just enough to release the tension in the casting from the 'push fit' of the end hose connection piece. Jammed in a small screw driver and it all popped apart - excellent I though, i can now clean & refurbish the unit.

Inspected it, tested bulb in hot & cold water - all fine.

Cleaned ally parts with fine wet & dry paper finnished with OO wire wool (great stuff by the way never used it before - its so fine it polishes!)

Got some metal loaded epoxy ready. Plumbers grade silicone grease. a small screw to lock it back together.

The end piece was still a tight fit so all that was needed was a simple locking screw incerted into a hole drilled through both pieces. And after all the unit only ever experiences vacuum when engine is hot.

[I have some pictures if someone can advise me how best to do pictures on this site.]

Anyway drilled the locking hole, plugged all the holes with metal epoxy, lubed the moving parts with plumbers silicone grease (should also retard the aluminium oxidising again as it repels water very good), put back together and locked it up with the screw.

I must say i was very pleased with myself having realised a replacement part would have been €150-500 online and i didn't really find this same solution online - so thats why i have posted here; maybe give others inspiration how to fix a buggered AAV - the main problem being to open it.

I think releasing the tension in the casting was the key. Many people i know have dremmels etc. these would be perfect for this task with a fine cutting wheel attached.

Originally i though of buying an internal puller but instead tried the free option.

Any tips on doing the photos?

[gf]

Hi wacotec! thanks for the post! ill give this a go on the old AAV. You can directly load up images from your computer to  a site Imgur.com- copy the link and paste it to a new thread. There are other ways too. type in "uploading images" in the search box on the top right hand side of the w116 page. There are a few folks that have varying ways of doing this

[wacotech]

So here is some pictures as promised:



Ready for reassembly, cleaned with wet & dry and fine wire wool.


Closeup of 'cut' (the larger hole is where I drilled out the locking tab first - may or may not be necessary?)




After reassembly with locking screw & metal epoxy glue.


Valve has been working flawlessly for a few weeks now.

Note: I did test the valve after cleaning but before final assembly to see how far it was closing in boiling water. It was closing about half way of the narrow section of the slot. (see 2nd picture)