I finally had a good day to flush my heater core on a 90 Blazer, full
First went to Wally world and bought a pistol grip spray nozzle for the
I found one with a really nice tapered nose that fit perfectly in the
end of a heater hose, not that cheap chinese one that costs two bucks,
nosiree, this cheap chinese model was a whopping 6.99!
Disconnected the input line from the motor and placed a piece of scrap
hose about two feet long on the core, disconnected the return line from
the radiator and started flushing. Went backwards first, blowing throgh
the return line hoping the reversed blast would dislodge any gunk in
the core, I never actually saw what youd call gunk, but a lot of
blackish discolored material was coming out. I flushed for a good 25
minutes reversing directions, till the water ran clear. It worked! I
have heat again.
It used to take a round trip to town, 16 miles, to get it to even begin
to start feeling warm, now it gets up to respectable heat after just a
few miles. A dramatic difference, saving me the hassle of a core