I've never worried much about having a working AAV but seeing Grant's great write-up in the JCNA magazine gave me a little enthusiasm for the project.

The thermo bulb on mine is kaput. The rest of the AAV is in great shape.

With a fair bit of fiddling others have adapted wax bulbs from various cooling system thermostats....but those write-ups are from many years ago. Before I go thru all that I'm wondering if anyone, more recently, has come up with a closer (or exact) match to the original?

Cheers and thanks
DD

 

I am not sure Doug.

I remember reading someone adapted a Volvo stat bulb, but I have no idea of the process he went thru to get to where it worked right.

I simply remove the AAV, job done. Done many of that litlle trick now.

 

Thanks Grant. I'll investigate the Volvo thermo.

I thought it would be fun to have a working AAV. Sort of like a novelty item! But, I'm not ready to devote huge time-effort into it.

Cheers
DD

 

Well, I now have a functional AAV.

I used the bulb from a marine application thermostat (NAPA part 18-3551). It has a 142ºF (61ºC) rating. This means a 'high idle' until 142ºF coolant temp....which seems a bit much to me. I would've preferred something a bit lower but couldn't readily get my hands on one.

Replacing the bulb was a small project.

First, cut the bulb out of the new thermostat-- 5 minutes.

Assuming your AAV is already disassembled it is an easy matter to drive the base (which holds the bulb) out of the main body. Use a socket as a drift, so to speak, and give 'er a couple good whacks.

Now remove the original bulb from the base. You'll have to pry out the circular sheet metal retainer....which in my case meant destroying it beyond reuse. Maybe you'll have better luck or, more honestly, more patience in removal technique. Anyhow, the seal (rotted out) and old bulb will fall out. The new bulb simply plops into the existing hole--prefect fit.

Having wrecked the retainer I used a generous portion of JB Weld to hold the new bulb in place.

The pushrod in the new thermo is too short. Pull it out and reuse the old pushrod. The old pushrod is a *slightly* bigger diameter. I chucked it up in the drill press and....ahem....'machined' it to the proper diameter with 220 grit sandpaper until it fit easily into the hole of the new bulb.

The unit bench tests fine. I have some slight concern over the longevity of the JB Weld....but only slight. The magic grey epoxy has never let me down in the past

Cheers
DD

 

Sweet.

So, not rocket science then?.

JB Weld has saved me many times over the years. Seems to last just fine once set up for the 24hrs they state.

 

Thanks.

I'll wait to see how it actually operates in the real world before getting too excited. I'm pretty sure that having high idle until 140º will be annoying....but we'll see.





Not at all, as evidenced by the fact that * I * was able to do it !






I love the stuff! My only concern is that, in this case, it's being used in an area that cannot be easily visually inspected over the long haul.

Cheers
DD