Changing Coolant in a 99 Concorde

I assume you have the 2.7L engine. Careful with that nipple - it breaks easily (the seat is an insert molded into the plastic body, and it can twist out), and the replacement of the part is expensive and labor intensive. Only loosen and tighten it when necessary, and tighten only enough to shut it off.

Mine has been weeping since I bought it three years ago, but is still OK otherwise. The amount of fluid lost is insignificant - I've never had to add any coolant since I've owned it - that's how small the leak is. Normally I'm in favor of fixing problems like that, but in this case, no

- not until absolutely necessary - hopefully never. A dealer parts guy told me that he has seen people purchase the new part, and the insert for the nipple twist out of the plastic the first time they open it. He also told me that if that happens, they don't provide you with a free replacement - you have to buy another one. Some deal, eh?

To answer your question, that nipple is to inject fluids for flushing and refilling, and for bleeding air out of the cooling system.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

One other thing, John -

On my '99 Concorde, I recently put a hose clamp moderately tightly around the plastic that the nipple and its seat are molded into.

The purpose was two-fold: (1) To reduce the seapage even further. And the visible seapage (residue from the dried coolant) is in fact less with the clamp on. BTW

- yours is probably like mine in that the seapage is greater in colder weather (almost none in summer) due to the difference in thermal coefficient of expansion of the metal of the nipple and its seat and the plastic housing that they sit in. (2) To hopefully greatly reduce the chances of the insert twisting out when I change the coolant, hoses, and thermostat this Spring.

Oh - also - just so you are aware - even though that whole piece looks like a thermostat housing, it's not. The thermostat is under a separate cover on the driver's side of the engine (on the side of the block - accessible from underneath).

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Also - you asked about draining the radiator. There is a petcock on the lower right side of the radiator - made for opening by hand - no wrenches. Pretty cramped quarters in front of the engine - probably need to access that from underneath.

To drain the system, you open that and the coolant pressure bottle cap, and the dreaded nipple that we talked about earlier.

There are also, according to the FSM, two block drain plugs - one on each side underneath each exhaust manifold.

I haven't done this myself, but, as I said earlier, I plan to soon. I don't know if those block plugs are really accessible or not. On previous cars I've owned, the manuals always talked about block plugs, and they did exist, but often they are totally inaccessible without taking things like the exhaust manifold off, which isn't worth it - easy for people to write into manuals, not always easy or possible to do. Hopefull we can access ours with little trouble (not holding my breath for that).

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Bill---Great info, and I really appreciate it. Like yours, the weeping is so insignificant that I won't worry about it...too much anyway! This car ahs been so reliable that I haven't even bothered buying a Haynes. I wonder if you would be so kind as to post a followup after you do the drain and refill this spring...just to let us know of any gremlins out there.

I can't believe that after 45 years of always doing my own work I'm actually considering letting the dealer do this job!

Regards, John

Buying a Haynes (or Chilton) manual and using it as anything other than amusement or toilet paper is a great way to make a car *less* reliable. They are full of wrong information. The factory manual's the only way to go.