Is coolant overflow reservoir pressurized?

[The_Handier_Man1]

From: ClydesdaleKevin  (Original Message)
Sent: 3/25/2005 7:34 PM

Well...another thing on the "to-fix" list.  Actually, its on the "to replace" list. 

Here's my question.  Is the cooling system on a 413 pressurized, or non-pressurized?  In other words, can you take the cap of the coolant overflow bottle once the engine is warm, or is it under pressure?

I ask this because when I inspected the bottle, I can see that there are actual holes in it!  Big enough to slip an easter egg into!  The old plastic is brittle beyond belief and just falling apart. 

I can get a generic bottle from the auto parts store, but was just wondering what type to get.  My guess is that its unpressurized, since only Jeeps in my experience tend to have a pressurized overflow bottle...but I wanted to make sure before I bought one.

Thanks!

Kev and Patti Smith



From: Movinyou1
Sent: 3/26/2005 3:08 AM

Anything beyond the radiator is unpressureized. Any aftermarket coolant recovery bottle should work just fine. The radiator cap is designed to keep the coolant in the radiator pressurized, usually about 16lbs. for most Mopars. So, have the cap checked (Autozone can do it for free) when you get your new bottle.    Leonard



From: denison
Sent: 3/26/2005 12:37 PM

The service manual calls for a 7 psi radiator cap for the 413s. Its what I use, and works fine with the 160°, 180°, or 195° f thermostats. The 413s on Winnebagos didnt come with coolant overflow bottles, and as far I can tell, did not need them. I change my coolant about each 2 years, and dont add any during the 8000 miles we drive in that time, much of it in South Texas in July/August.
The Futura coach builder may have added the coolant recovery bottle, or a previous owner who didn't want to take his radaiator out for cleaning.
I have used a 50% water-antifreeze mixture, am now using 70% water, 30% antifreeze. Water conducts heat better than ethylene glycol, and doesnt expand as much with heat either.