"(Donna Cassano)" wrote:

> <snip>Also, not sure if I have the right cap on the expansion tank. It doesn't
> look
> like it has any kind of pressure releasing mechanism. Should I see one? It is
> blue plastic, made in Germany and says "Blair" on it. Don't see a part # on it,
> but I haven't taken it off.

Donna,
When you take it off, you'll see the valve inside the cap. The older cap was black,
the newer are blue. I have one light blue and one dark blue (as a spare). Ii threw
away the black one.

> Still worried about adding air to the system by
> removing cap.

Wait until the engine is completely cooled down before removing the blue cap. You
will NOT let air into the tank. If it already has some air, then you can add some
coolant to top it up before replacing the cap. Remember to remove the small rubber
tube from the cap before you turn it. The cap tends to get quite tight. If you
don't apply any force to the nipple, you shouldn't break anything. While you are
examining your expansion tank, take a look at the plastic near the cap. This is
where aging tanks tend to form cracks. These cracks leak air in and coolant out.
There is no permanent fix for these cracks. Just replace the tank (about $20 I
think). Remember to secure the rubber tube to the cap after you replace it. BTDT

> Are these fears unfounded?

Knowledge is power.
-Larry