Maitenance Questions, 4.9L 1993 Deville

[93DevilleUSMC]

Hello,
I had stop-leak tabs put into my coolant reserve tank, and my radiator flushed last November to seal a small leak I had within the tank. The problem hasn't reoccured, although I hear that it is neccessacry to have the above procedure repeated twice a year. Should I have the coolant flushed again soon?

[HUF]

Originally Posted by 93DevilleUSMC

Hello,
I had stop-leak tabs put into my coolant reserve tank, and my radiator flushed last November to seal a small leak I had within the tank. The problem hasn't reoccured, although I hear that it is neccessacry to have the above procedure repeated twice a year. Should I have the coolant flushed again soon?

First, never put tabs in the tank. They can plug the hose which connects the reservoir with the radiator neck. Put them directly into radiator instead.
Second, the radiator side tanks are plastic and they are known to crack. You cannot repair a crack. Just replace the radiator. Where was exactly the leak?

Yes , many of us replace the coolant and tabs (Bars Leaks golden seal powder in tubes) every year. The manufacturer suggested every two years though. You do not have to flush the radiator, just drain as much as possible and replace with fresh 50/50 green Prestone/ Distilled Water mix (with coolant supplement - two tubes). I Usually siphone the coolant right through the neck of the radiator with 1/4" tube. That way I get about 1.5 gal of old coolant without making mess.

[93DevilleUSMC]

Originally Posted by HUF

First, never put tabs in the tank. They can plug the hose which connects the reservoir with the radiator neck. Put them directly into radiator instead.
Second, the radiator side tanks are plastic and they are known to crack. You cannot repair a crack. Just replace the radiator. Where was exactly the leak?

Yes , many of us replace the coolant and tabs (Bars Leaks golden seal powder in tubes) every year. The manufacturer suggested every two years though. You do not have to flush the radiator, just drain as much as possible and replace with fresh 50/50 green Prestone/ Distilled Water mix (with coolant supplement - two tubes). I Usually siphone the coolant right through the neck of the radiator with 1/4" tube. That way I get about 1.5 gal of old coolant without making mess.

The leak was somewhere on the bottom of the tank. I haven't lost any coolant out of it since November when I had the tabs put in, so I do believe it is working. The radiator's given me no problems, so I don't plan to replace it unless absolutely necessary. Should I perform the siphon/replace coolant procedure ASAP, or wait a couple of months?

[HUF]

Originally Posted by 93DevilleUSMC

The leak was somewhere on the bottom of the tank. I haven't lost any coolant out of it since November when I had the tabs put in, so I do believe it is working. The radiator's given me no problems, so I don't plan to replace it unless absolutely necessary. Should I perform the siphon/replace coolant procedure ASAP, or wait a couple of months?

The tanks crack usually in the upper portion. Your leak is probably from a connection to the cooling lines.

You do not have to do that ASAP, just a common sense approach.

[93DevilleUSMC]

I'll have it looked at again, and probably have what you suggested done this summer. Thank you!

[100]

I had a leak from the similar location. A big hex nut looking metal part that holds the fitting to the radiator side tank was loose. I really can't describe well, but the oil/ATF coolers have two fittings coming out of the side tank and there are those hex nut looking things holding those fitting to the side tank, thus effectively sealing between the fitting and the tank. When you look at the side tank, I think it is quite trivial what I mean. You may want to check if they are not loose.

Good luck.

[93DevilleUSMC]

Thanks for all of the info!