Draining cooling system

[MaineShark]

Joe, you don't flush it yourself? Do you take it to someone else then?

To just change the coolant, I drain it and replace it myself. For an actual flushing, I figure it's worth a few bucks to have it put on the machine, since it will do a better job than a home kit.

Joe

 

[Jack]

TR:
DO NOT attempt to remove a freeze/frost plug from block unless it is actually leaking.

NEVER refill a HOT motor with COLD water/coolant.

Install the Prestone or other brand backflush kit ... drain system & backflush until clear. Then use a cleaner.

The very best is "Prestone Heavy Duty Cooling System Cleaner" Prestone P/N AS100 ... it is a two-part dry powder that comes in a canister similar to a pringles can ... it's far superior to the wimpy but readily-available modern-era liquid flushes/cleaners ... it's been around for decades but due to its relative high strength it can be very hard to find on auto parts house shelf these days ... GM recommends it in current GM service bulletins ... GM dealer carries it under GM P/N 12346500 ... about $6. When used per directions it is safe for aluminum, brass, copper & iron. I've used it & am very pleased with results ... it cleaned the livin' crap outa the system & no leaks.

After you've cleaned & neutralized system with AS100/12346500 as per product's directions ... then drain & backflush again until clear.

Then drain system & R&R intake manifold as needed ... go ahead & install new thermostat & new radiator cap. Refill w/ conventional green antifreeze:distilled water mix.

Every two years ... drain & backflush 'till clear ... drain ... refill w/ new antifreezeH20 mix.
JACK:gap

 

[Stallion]

Okay, thanks for all the tips, everyone!! I'll have to read this thread over numerous times. Thanks again!

TR

 

[Buckskin7T7V]

On my L-48 I took out the block plugs and installed the same type of drain valve that is on the bottom of the radiator. One is located on the block in front of the starter motor and the other one is located straight across from that one on the other side. I open them up to do a complete block drain and flush.

 

[Stallion]

On my L-48 I took out the block plugs and installed the same type of drain valve that is on the bottom of the radiator. One is located on the block in front of the starter motor and the other one is located straight across from that one on the other side. I open them up to do a complete block drain and flush.

That sounds like a tough thing to do for the first time, but once installed, it is probably the best thing you could do. Sounds good, thanks for the idea.

 

[Bob Chadwick]

Those plugs are also named "freeze plugs" with the function of hopefully blowing out rather than cracking the block should you not have a low coolant situation with frozen antifreeze. Any tinkering with them need to take this into account.

 

[Dave L.]

Bob - I think he is refering to those 2 threaded plugs on both sides of the block rather than the actual pressed in freeze out plugs.

Dave

 

[Bob Chadwick]

Bob - I think he is refering to those 2 threaded plugs on both sides of the block rather than the actual pressed in freeze out plugs.

Dave

Gotcha.

 

[Buckskin7T7V]

The freeze plugs are 1 inch cups that are pressed into the block. They are designed to pop out, when freezing occures. Leave these alone. Drain plugs are about 9/16" hex nut brass plugs.

 

[JohnZ]

Trivia - although they're commonly called "freeze plugs", they have nothing to do with protecting the block against frozen coolant; those holes in the block are there so the foundry cores (sand) have a place to get out of the raw casting when it comes out of the mold and hits the "shake-out table".

 

[Bob Chadwick]

Trivia - although they're commonly called "freeze plugs", they have nothing to do with protecting the block against frozen coolant; those holes in the block are there so the foundry cores (sand) have a place to get out of the raw casting when it comes out of the mold and hits the "shake-out table".

Learn something new everyday.