I just replaced the heater core on my 2000 Blazer. It let go while vacationing last summer in Gatlinburg and Bars Leak "fixed" it. Well I finally tore out the dash and replaced the heater core. Wouldn't you know... as soon as I flushed out the Bars Leak and replaced the coolant, thermostat and radiator cap, the radiator sprung a leak!

I am going to change the radiator this week. I am debating on whether to change the water pump while I have the radiator out. The truck never got over about 240 degrees but it dumped all of the water a couple of times before I could get it home. I think the water going through the water pump helps cool and lubricate it. So, I'm thinking I should go ahead and change it...

What does everyone think?

Thanks,
Chuck

 

According to RockAuto, you can get a cheap pump for 30, for an AC Delco for 48....with that relatively low cost compared to your other repairs you're doing, I'd say go ahead and replace it...but that's just me

As far as needing to replace it, if it's not weeping or throwing coolant out, you should be ok..

 

Maybe someone else knows exactly what the chemistry is that'sgoing on, but my understanding is that Bar's (and the like) cures in the presence of air. I had exactly the same sort of problem, but it was when my intake gasket went out andwasemptying the cooling system. Then the rad sprung a leak (had some Bar's in there instead of GM pellets). Radiator guy told me to avoid those stop leaks because they can cure if there's air in the system and cause too much backpressure, and finally a leak, especially if you put too much in. Fortunately mine was only the side tank, but still $70 to fix.

GM actually specifies that some sealantpellets should be put in at every coolant change, but they are diff (?) I guess.

 

I was talking to one of my neighbors who was a mechanic for a Pontiac dealership for a long while, and he said the exact same thing. He referred to them as oatmeal pellets

Basically its floats around till if finds a leak (air), and expands. The problem most people have is that while the GM pellets are good and not too dangerous, when people put in Bars leaks, they dump an entire bottle, causing some serious problems.