Had To Repair The Radiator

[ZZ]

The radiator on my '90 sprang a couple of leaks over the weekend. I pulled it out and took it to the local radiator shop. He said it was in excellant condition for it's age with no core rotting. The tank on the right side was trying to push out.

I put it back on today. It seems to have a problem building pressure. The upper hose feels like it has about half the pressure it normally had. I bought a new 16 lb cap and it made no difference. It doesn't seem to be losing coolant and I can't find any leaks.

Would too much air still trapped in the system keep the pressure down?

[john8662]

Yes, air in the system could cause what you're seeing. I'm guessing that in your '90 you still have the filler cap so you can see the level of coolant in the radiator by opening the cap. What I always do after losing coolant is burp the upper radiator hose. Just open up the radiator, and squeeze the upper radiator hose forcing air into the radiator, you can watch your water level to make sure you don't make a mess. I usually get another 1/2 gallon in by doing this, but this is before starting it. After it's started, just add coolant until it won't take any more, then check the next morning when cold and add. Sometimes it takes a little while to get all the air out.

[ZZ]

Thanks for the response. It pulled quite a bit of coolant from the overflow tank overnight. So, the level is now right up to the top of the neck. Maybe it worked out some of the air by that. I'll keep a watchful eye on things.