"Peter Griffin" > wrote in message
...
> Ok...same 99 Gmc Savanna 5.7l as usual...now I just finished changing the
> intake manifold gaskets, and I figure I'll scab up enough tonight to
> undertake the coolant flushing tomorrow...Question is a friend suggested
> vinegar as a flushing agent...Any pro's or cons will be appreciated...I
> just planned on filling with water getting to temp...draining a few
> times...thanks in advance ...

Here is how I did my last coolant flush,

1) Opened radiator drain petcock fully
2) Disconnected one of the heater hoses going to the heater
core at the firewall
3) Opened radiator cap.
4) Waited until all coolant drained.
5) Inserted garden hose to overflow bottle cap and held
hand around hose and cap, turned on water half pressure until
clear water running from overflow host to radiator.
5) Inserted garden host to rad cap and wrapped a rag around
the area, held rag on with hand.
6) Turned on garden hose full until water running from petcock,
heater, host to heater was running clear, about 5 minutes.
7) let system drain.
8) closed everything up, poured in full bottle of antifreeze, not
diluted.
9) Filed remaining with 50/50 antifreeze and water. Ran car and
topped off when it burped, then drove car and over the next
few days using a antifreeze tester, added antifreeze and mixture
until cooling system completely full.

Ted