What are your opinions on Bars type stop leak componds for cooling systems?? I have used the Bars ball type sealer in the past, it worked, but only for a while. I own a full size older Dodge van, and don't like the idea of working on the cooling system, but will end-up doing it. Let me know if you know of an effective product. thanks

 

First off, why do you need to put it in? Is it a leaking radiator? Head gasket?

The previous owner of my old work truck thought he had a bad head gasket (it was a valve guide seal), and he put bars in there. It turned everything sludgy as heck, and 2 years later, after two flushes and a water pump replacement, the coolant was STILL sludgy and discolored, and probably led to the water pump failure.

My personal opinion is don't use it unless you really have to, like to try to stretch some more miles out of a bad head gasket.

 

The stop leak products that contain the black/brown tar pellets will gum up your system. Never put that stuff in.

By far the best stop-leak product is the powder (this too is made by Bars Leaks, but it is good) that comes in two varieties - silver and gold. I have used both with excellent results. I think the gold powder is more expensive because it contains lubricants and additives to control electrolysis.

If the powder does not work for your situation then you are probably looking at making repairs to the cooling system.

 

I agree with Rusty. Stop Leak isn't that bad of an idea, especially for reliability purposes. GM now puts it in at the dealerships anytime the cooling system is worked on.

 

Just to let you know of my experience with Bars Stop Leak... years ago I owned an '89 B250 with 318 and over 200K miles on it. I started to lose coolant from a rusted freeze out plug, then another. Over the course of a year, I used several cans of Bars pellets in the radiator. The van was driven back and forth to school and around local trips by my college age daughter. Finally I got it up on a lift and decided to get those plugs replaced. Hanging from 3 plugs were "drip formations" almost like candle wax that had dripped and hardened on the side of a candle. Those formations were from the Bars that had leaked and hardened outside of the engine block.

The plugs got pounded out and replaced and I flushed the cooling system with plain water. After refilling with coolant, my daughter continued to drive the van. It lasyed in my family another 10K miles and I finally sold it in 2001 with over 260K miles on it still running fine.

 

Problem with that stuff is that it does the trick on radiator cores and coolant passages too. I've pulled radiators where you could visibly see long ribbons of that nasty stuff running out of the core tubes. I've taken water pump housings to get that crap sandblasted out, after everything else failed to do it.

Use it if you will, but it becomes a part of your cooling system forever.

 

That's why I only recommend the powder from Bars Leaks. If that doesn't do the trick then bite the bullet and make the physical repair(s) to the cooling system.

 

I've used the brown/black pellet Bars Leak numerous times with mixed results. It has almost never worked for serious radiator leaks, but for me it has worked well for head gaskets. It does make a huge mess.

Ideally, any of the "quick fixes" like stop leak and fix-a-flat should only be for emergency use as they frequently create more problems than they solve.