Just wanting to know how to tell if the bellows are good or not? Is there a length it should be at room temp? I assume its fine, it was my dd for years w no problems to speak of. The engine will be going back in the car in a few weeks and its something I don't really want to spend more money on but I want to be right. So what do you guys think?

Haynes manual, page 13-14 says heat a pan of water to 150-160 degrees F, put your thermostat in the water for a few minutes, and overall length should be 1.81 in (46 mm). An eyeball method is to warm up the water, drop the thermostat in, and see if it expands.

Olin

Lets see a pic of the thermostat. It is obvious by the room temp position if the thermostat is good.

take a peek at this thread - bottom pics in boiling water

http://www.914world.com/bbs2/index.php?act...=0#entry1551011

and see this
http://www.914world.com/bbs2/index.php?sho...mba++thermostat

should be compressed at room temp and expand about 1cm hot ??

Can you squeeze it closed? probably bad.

It's assembled in compression, alcohol is added then it's sealed with solder. Heat makes the alcohol expand. So, if its long, it likely either has a slow leak or is cracked and dead.

Yea thats what I said!

There is a guy on Samba selling new ones for around $100. Why bother with a 40 year old part that will fail.

Why bother with a 40 year old car that will fail?

--DD

Thanks to all you guys for the info. I also see there is another thread about this w pics that is helpful. This wkend I'll add some pics and test mine out. Reharvey I think AA has them too for about the same $.

Here is a link to modify a type 1 type 1 themostat mod