pressure checking a cooling system

[Greg Linton (45455)]

I'd like to pressure check my radiator before I clean and paint it and was wondering what pressure I should use for testing it? I know the cap is good for 15lbs so should I stick to this pressure or bump it up a bit?

It's the original BB rad and I have never had any cooling issues so I don't expect any problems but it is such a royal pain to R&R this thing that I want to make sure that it will be okay.

Also, what would be the correct black for a 69 radiator?

Thanks again.

[Jack Humphrey (17100)]

Re: pressure checking a cooling system

With the radiator out of the car, the easiest way to pressure check it is to take it to your local radiator shop. They'll have the fittings and observation 'pool' already set up. A word of caution though, RESIST the temptation to have them clean the radiator! I've seen more than one spring pin hole leaks after a professional acid bath clean up...

[Greg Linton (45455)]

Re: pressure checking a cooling system

Thanks Jack but I already have it all pretty much set up and ready to check. I'm just a little unsure of how much pressure to use.

Sometimes I think I'm crazy to take on some of these "little" projects but I just feel like I have more control over the out come if I do it myself. My Dad always says to not get them boiled out as well as long as it was cooling fine before so that's good advice too.

[Jack Humphrey (17100)]

Re: pressure checking a cooling system

"Thanks Jack but I already have it all pretty much set up and ready to check. I'm just a little unsure of how much pressure to use."

In that case, install a Stant pressure checker and pump 'er up to the rad cap's rated release point (13-15 lbs) and verify she holds there... They can take more pressure (design safety margin), but don't push it with an aged original as she's not going to see pressure above the rad cap's release point anyway.

[Greg Linton (45455)]

Re: pressure checking a cooling system

Ya you're right Jack...I wasn't thinking...no need to pressurize the rad much higher than the cap will allow. I think I'll check my cap and then test the rad to 1, maybe 2 psi more at the most and call it good.