I have a Canton expansion tank on my mcs right now.

It has a Stant 18psi cap.

Looking on the Canton website the recommend their 30psi cap.

I know other alloy expansion tanks are running 16psi Stant caps.

So just wondering if anyone knows the proper cap to use for our application?

 

Canton has a fancy 16psi cap;

https://www.cantonracingproducts.com...pansion-tanks/

16psi is factory correct.

I have a no-name alum exp tank and run it with a stock cap --- I was using a 105 kPa (21psi) Volvo cap for a while but got paranoid because of possible damage to cooling system by exceeding factory limit, so I switched back to a stock cap.

 

Thanks found one on Amazon from Canton for $27 shipped. Same one you posted.

Let's see if it works out.

Right now having an issue where the coolant is being forced out the vent on the canton tank when running the car hard.

Funny thing is coolant temp never seems to get above 200 F even with hard driving. I have a pretty large aftermarket alloy radiator.

Might have to bleed the system again maybe I have some trapped air somewhere.

Hoping its just as simple as a cap fix though.

 

Interesting thread. I, too, have a CANTON tank and am using a STANT Racing 22-24 lb cap. I'm not getting any coolant out the vent tube of the CANTON tank (I rigged up a catch bottle) but I have had a couple of MISHIMOTO radiators fail due to small leaks at the interface of the tubes going into the side tank just below the upper neck. My thinking is that the radiators have failed due to poor welds rather than high pressure. 22-24 lb. is not excessive pressure. Even a standard MINI radiator's rated test pressure is 1.5 bar or 21.75 lb. I may go down to an 18 lb. rated cap to see what happens...if anything. FWIW, I e-mailed CANTON and asked why they specify a 30 lb. cap with their tank. The tech rep answered that he, too, was mystified. He asked numerous people within the organization and couldn't get an answer!

 

I am on my third Mishimoto; the first two had a leak exactly where you describe.

 

So far knock on wood my Mishimoto is fine on my mini.

But I went through 3 units on my 6.7 powerstroke before I just went back to the stock one.

Mini radiators are cake to change. On my truck not so much!

 

JAB 67-Sent you a PM. Please reply. Thx!

 

Reviving a thread here..

Just got myself a canton tank and cap and every time I drive it hard I get tons of steam because coolant is leaking out of the valve on the top that is supposed to release pressure. Wondering if and how you fixed this problem? Thanks!

 

I use a STANT Racing 18-22 Lb. cap with a length of vinyl tubing from the vent tube over to a clear plastic squeeze bottle used for ketchup or mustard placed in the cowl cavity. I rarely get any overflow, even after a hard half hour on track. Just be sure you don't have too much coolant in the tank.

 

You would need to use the 30 PSI mini radiator Cap, Part # 81-030

 

Whatever psi cap you decide to use, I've determined that having the correct level in the tank is the cure. When cold, the coolant should only be about 1-inch above the bottom of the tank.I use a length of wood dowel for a "measuring stick" marked with a Sharpie at the correct level.

 

The Bentley manual states the coolant system test pressure is 14 to 18 PSI.

Then it warns that going above test pressure could damage system.

16 PSI seems to also be repeated as the stock cap pressure.

I picked up a Stant 10230 and it fits up fine.