Radiator neck repair is easy and cheap

[BriceW at webtv.net]

The upper radiator neck broke on my 91 200TQ20V 2 weeks ago. I was able
to sinch it up and drive for awhile but it would come off again. So I
carried gallons of water for a week till I could replace or repair it.
The cheapest new OEM radiator I found was $239.00 from the www.parts
connection.com at 800-472-1144. Part no. is 443 121 251AA.
I asked him about a metal radiator for the 20V and he said that he once
heard that
www.nissens.com made one that had the extra outlets for the auxillary. I
found one on the site under Model No. 60437. I looked at the back and
front pictures of it and it looks like it has the extra outlets.
But I could find no one in the USA that carried that model no.
So, I found the Audi Service bulletin site
and called 800-544-8021 and ordered the service bulletin A19002 which is
Broken Radiator Neck Repair. It cost me $2.13
shipped. It is cheaper to order by phone.
The bulletin is for all 5000s but it works for 200s as well. They also
have a bulletin to fix the expansion neck.
I then ordered Audi part no 200121001 which is a very hard black plastic
insert that fits snuggle into the broken radiator neck from a local
dealer for $20.00. The dealer wanted $50.00 for Audi part no. 200121003
which is a 2 part epoxy glue and that number had been superceded by a
kit. I was lucky and found the original expoxy at an Audi dealer in
Boulder. It had been used and the parts man was going to ship it to me
free to use some and ship back. I paid him $13.00 shipped and kept the
tubes. Very large tubes made by Kent Industries in Cleveland,Ohio. The
Kent Pt. No is 20250 and the stock no. is EA-W and the Audi Pt No. is
200121003.
I didnt trust using any of the many expoxys I found at Auto Zone as I
couldnt figure out what types of plastic I had and what would not bond
with what,polythylenes and such and tempatures and chemicals,etc.
My trusted Audi mechanic told me that he had done many of these repairs
and i always worked. He said to file down the upper neck so that it was
flush which I did and which the service bulletin didnt specify.
Then I used 80 grit sandpaper and lightly sanded the inside of the neck.
My mechanic told me to also lightly sand the insert as well which I did.
Then I applied the epoxy around the insert and fit it snugly into the
broken neck. I filled and smoothed any gaps I had with more epoxy but I
didnt have many thank to filing the neck flush first.
I then let it cure for 24 hours as my mechanic recommended. The bulletin
says only 1 hour.
Then 24 hours later I re-attached the upper hose and using a new clamp.
Dont super tighten the clamp. This is what causes a lot of the necks to
break. The new insert is super thick and strong and should never break.
I then put new antifreeze in.
I have driven for a week of hard driving and it works great.
The total cost was $37.00.