Cold radiator under pressure, bad radiator cap?

[pickupman]

The truck has been sitting since Monday and has not run since. Today I went out to top off the oil and check the fluids. When I took off the radiator cap, it puked coolant everywhere. Mind you the truck has been sitting all week and was not run today, so I don't understand how the radiator could have that much pressure still.

 

[FoolhardyIDI]

Make sure you are running a 13psi cap. A new cap is cheap and good insurance. Also check your overflow tube it could be clogged.

 

[pickupman]

A new cap is on this list. The current cap is also a 13psi cap. It looks old, and since I got the truck in 2010, I haven't replaced the cap, so maybe it's time.

 

[IDIoit]

i would assume, you havnt changed the coolant either?
id put that on the list also if so...

 

[pickupman]

i would assume, you havnt changed the coolant either?
id put that on the list also if so...

Yeah I need to do that too.

 

[OLDBULL8]

You could have the radiator way to full, the level should be down 1-1/2" below the top when cold. You should almost see the core tubes.

 

[Sorro71]

Apologies if I have hijacked your thread. What type/ brand of cap would you guys recommend?

 

[Zaggnutt]

I can't comment on longevity, but I replaced both of mine with Advance Auto caps that were roughly $6.00 per. I noticed an immediate difference in sealing ability. The other choice is a cap with the pressure release arm on top, but if you are using 13psi rated cap it should be good.

 

[FoolhardyIDI]

I use Stant #10329 with the pressure release arm. I have used Stant for 18 years on all my vehicles. I also like the idea of being able to release the presser into the overflow tank and not the ground. If checking when hot.