Popped the hood yesterday for visual inspection. Upper radiator hose was flatter than a pancake. Replaced hose today. Operated normal until engine was shut off and temp cooled down. Again flatter then pancake. Coolant level full. Whats up with this????

im gonna say that you have air in the system...

you need to burp the air out...

drill three small 1/8" holes in your thermostat..

and idle car until fully warmed up...

then fill and cap..

You could also have a radiator cap not venting properly.
Not only does it have to allow pressure out, it must allow coolant or air back in when it cools and creates a vacuum. This is true with or without a overflow tank.

Ben, could I have air in mine? I used the type of t stat that is supposed to be failsafe. When I ran the car this weekend, I got a gauge reading of 210 and climbing before I shut it down, the engine felt a lot cooler than that and the upper hose, though not collapsed, was cool to the touch. I felt the hose about 30 minutes later and it was hot, but not overheated hot. I also had to put a short pigtail on my sender wire, the sender I got that is supposed to be right has the thumbtack top, my new wire harness has the bullet type connection on it. Haven't been able to find a sender that has the right end on it.

what type of thermostat is this ??

does it have any air bleed holes ??

in theory it only takes one hole to let the air bleed out..

but when stewart sells a "high flow" thermostat... its just a good thermostat with three small holes..

the last failsafe unit I had didnt have any holes.. just guaranteed to open.. but even they wont open properly if there is air in the system.

also you may need to calibrate your gauge to your sender..

|UPDATED|9/28/2004 3:04:13 PM (AZT)|/UPDATED|

I was thinking I was getting a false reading as far as numbers. After the first "heat up" I really didn't think the engine got all that hot and suspected air. I topped off the reservoir and let it run for a couple of minutes with the cap off, when it started to regurge out of the top, I replaced the cap. That may be where I goofed. Maybe I should have let it go ahead and burp the air out? I got the stat at the zone and don't recall the brand, if it fails, it's supposed to fail open. Heater hoses got hot too, but again, not overheated hot, so I know the pump is working.