Cat C-12 radatior cap pressure

[djhinds]

My non-internet friend has a 2004 Beaver Marquis with a C-12 engine. We just got an exact replacement for the surge tank. The old one was cracked around the filler neck. It had a 7# cap on it, is that correct one? I read on the Detroit 60 engine it should be a 13# cap due to the sleeves and cavitation damage at only 7# pressure. Does that happen in Cat C-12 engines?

Dave

[1ciderdog]

Maybe a telephone call to a Cat dealer would get the best answer.
Safe Travels
Bob

[Bigbluedog55]

Hi Dave,


I have the CAT C12 engine in my Country Coach, and it has a 13 pound cap on it.

Just my .02

Luck,
Bob

[spike45]

Quote:

Originally Posted by djhinds My non-internet friend has a 2004 Beaver Marquis with a C-12 engine. We just got an exact replacement for the surge tank. The old one was cracked around the filler neck. It had a 7# cap on it, is that correct one? I read on the Detroit 60 engine it should be a 13# cap due to the sleeves and cavitation damage at only 7# pressure. Does that happen in Cat C-12 engines? Dave

Generally, engines built before 2007 had lower cap pressures. After 2007 most manufacturers went to 13 PSI cap pressures due to higher coolant temps and EGR (non-CAT). Running 13 PSI should not be an issue. The limiting factors are hose connections. Running low cap pressure or having a defective cap will result in easier formation of cavitation bubbles which cause pitting of the cylinder walls. It does not matter if the engine has replaceable liners or parent bore (no liners). Pitting is easier in systems with low cap pressure or defective pressure caps. Get them checked more than once per year.

[djhinds]

Thanks spike45 for the answer. We just replaced the coolant recovery tank and the radiator cap is on it. We will put on a 13# cap after a pressure test. The old one was cracked near the cap and would not hold pressure.

Dave

[docj]

If you search the http://forum.bacrallies.com/cgi-bin/forum/Blah.pl? for this topic you will discover that the surge tanks on C-12-equipped Beavers of this period were prone to cracking and quite a few people are using 7 pound caps to help prevent this from occurring. I have a 7 pound cap; the engine runs at 190F and 7 pounds of pressure should raise the boiling point to 225 or greater. There is probably a slight increase in coolant loss at the lower pressure, but I top it off occasionally with CAT ELC premix.

[lyledavid]

Cat C 12 Rad. Cap
I have a 2005 Fleetwood Revolution 39A on a Spartan Chassis and it doesn't have a recovery tank a call to Spartan verified this and I have a 16# psi rad. cap installed, My engine is not a Cat C12 it is a C7. This post is for information only. If in doubt call the engine manufacturer. Apparently these specs. vary by engine size and year. Thanks to EPA rules.
lyledavid