Radiator Cap

hax · 08-16-2009, 09:31 PM

I have coolant coming from my radiator reservoir overflow at about 180 degrees. I've checked the temp at the reservoir with my infrared thermometer and replaced the cap with a new 16psi one. Does anyone know if this is the right psi cap or have any ideas as to why I'm overflowing at such a low temp? Thanks Jim

dgerstel · 08-17-2009, 10:03 AM

Hax,

Check this thread out.
What is a Surge Tank?

dshogman · 08-17-2009, 11:37 AM

Dale, is the pictured overflow tank a kit or did you make it up yourself? What about the holder?
Thanks.

dgerstel · 08-17-2009, 11:54 AM

Dave,

Bought tank, hose and bracket while staying at camp Walmart, at their auto parts section.

SteveS · 08-17-2009, 12:44 PM

I did somewhat the same as Dale and have not had to add coolant since. Being the cheapskate I am and not realizing there are aftermarket overflow systems, I just used a gallon coolant container and drilled a hole in the cap and shoved the overflow hose through the cap to the bottom of the container. Velcroed the container in the compartment.

hax · 08-17-2009, 12:52 PM

Dale, Thanks for the info, I'm on my way to camp Walmart now. I must have a tipped sight glass in that I have never seen anything but green in the window. I replaced the surge tank cap in Ennis, Mt just before I drove home to Scottsdale (took 3 or 4 days) I would have thought that if it was overfilled, it should have drained down by now. I backed out of my yard yesterday and as soon as it got up to about 175 to 180 it started to overflow again. How many lbs is your cap? I just bought another cap in case I got a bad cap.

dgerstel · 08-17-2009, 01:33 PM

Hax,

Mine is 16 lbs vented. Like Mike and Mike in the linked thread, even though my tank looks level, I have found that there can be fluid in the window while the fluid in the tank is lower than the window.

dshogman · 08-17-2009, 02:38 PM

Dale & others,
If you have a coolant recovery tank set up, do you then fill the surge tank to the top when cold?
Thanks.

Jeff_S · 08-17-2009, 04:03 PM

Quote:

Originally Posted by hax

... replaced the cap with a new 16psi one. Does anyone know if this is the right psi cap ...? Thanks Jim

I was considering replacing mine as preventative maintenance. It is stamped with 14psi on the top. However, I am NOT finding 14psi in the auto parts stores only 13 & 16 psi as the closest.

So, again, what is the correct cap pressure rating?

EngineerMike · 08-17-2009, 08:30 PM

Mine is 16psi.
The coolant peep site on mine is labeled coolant level cold. If I fill it to have coolant in the window when cold, it will push coolant out so next time cold there is no coolant in the window. However, I have discovered that starting the engine will boost the coolant tank level to show coolant in the window. So that is now my coolant check process- lift rear engine door, start engine & check coolant. No coolant in the window & I need to add some.
On my 06 I used a kitty food container w/hole in lid for an overflow, and never needed to add any; the hot engine pushed some out into the overflow (which I could check when pulling over for a rest), then sucked it back overnight. Haven't gotten to that chore yet on the 08.

SteveS · 08-19-2009, 01:51 PM

My cap is 14 lb. I have never had it tested but since I added the makeshift overlflow (above) I have not had to add coolant. I put coolant in to just cover the view glass when cold.