On my 300G I found that my gauge was way off calibration. I had the hot indications, too, but no boil over, etc. Got a calibrated gauge from Carter, sent him my old one. What a difference! Tony -----Original Message----- From: mailing-list-owner@xxxxxxxxxxxxxxxx [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Brad Hogg Joe. 1. Yes, it does matter. A cap with too low of pressure will let the car boil over at a lower operating temperature. A 15 or 16 lb cap should be readily available. 2. I find I can test the thermo-clutch fan by starting the car and allowing it to warm up at idle. You should be able to detect the fan increasing in speed as the engine gets warm. The fan will blow much more air past the engine when the clutch is engaged. You should be able to find a replacement clutch easily. Measure the length of the clutch from water pump to fan. You won't have to replace the fan with the clutch. 3. Dunno. ----- Original Message ----- Out joyriding this weekend, I noticed that the temperature gauge was running on the "hot" side. This was most pronounced in city traffic. At highway speeds the temp gauge moved back to the left/closer to center. In working on the car, I replaced the temperature sending unit and the thermostat. I have done no work to the radiator, fan/fan clutch, or the water pump. The car does not boil over or at least it hasn't yet, though I have had to add coolant to the radiator from time to time. Evenso, I have not noticed any coolant leaks and all the hoses look and feel good. Q#1: I noticed that the radiator cap is a "7 psi pressure" cap whilst the FSM indicates it should be a 16 psi cap. (car has A/C). Do I need to replace the cap and does anyone have a source for a 16 psi cap? What are the effects of an improper radiator cap? Q#2: The FSM indicates that high temp or overheating at low car speeds may indicate problems with the fan drive (clutch, I assume). I have looked over some of the archive comments about this procedure but couldn't find anything about 1961 in particular though there is some good information in the FSM. Is the "process" of testing/removing/repairing the fan/fan clutch relatively the same regardless of year? Any thing I need to watch out for? Q#3: I am having some difficulty finding a water pump for the 1961 Imperial at parts houses' on-line catalogues. Is the water pump the same for all '60's era Chrysler 413 engines and does it make sense to replace it if it hasn't failed (as far as I can tell)? As always, thanks everyone! -- Joe Allen, Texas ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm