coolant flush question

[joecutlass]

im sure this was brought up in the past here, maybe not. but im planning on backflushing the coolant in my 95 gp. the haynes repair manual says to add two coolant supplement pellets... is this true? ive backflushed systems before and never put pellets in. any feedback would be splendid

[Schurkey]

I wouldn't bother with the pellets.

[joecutlass]

So should I just backflush the system like I usually have done in the past?

[Schurkey]

I don't know how you did it in the past.

 

All I'm saying is that I wouldn't bother with leak stop pellets. I would install a 50/50 or stronger mix of quality anti-freeze coolant and distilled water when the flush is completed. (After draining the block and radiator, of course.)

[AL]

I usually drain all of the coolant and use a garden hose and spray it both ways through all hoses and the heater core and let it flow through the radiator for a while and then fill it back up with 50/50 mix

[joecutlass]

What about the flush anf fill kit from prestone? It basically installs a tee at the heater core hose, attach a garden hose, pul the rad cap off and pull the thermostat, reinstall thermostat housing, turn hose on and run car with heat on high for 10 minutes or until water is clean...

 

My concern, Cold water + running engine(heat) = what?

[joecutlass]

Well anyways, I did the flush and fil kit from prestone. Car runs between 160* and 240* now.

[Schurkey]

I usually drain all of the coolant and use a garden hose and spray it both ways through all hoses and the heater core and let it flow through the radiator for a while and then fill it back up with 50/50 mix

50/50 PREMIX coolant is often almost as expensive as "pure" antifreeze. Better to buy pure antifreeze; and mix it yourself with distilled water.

 

ALWAYS DRAIN THE RADIATOR AND BLOCK of all the flush-water before refilling ESPECIALLY if you use premix coolant. If you don't drain out the flush water, you'll never get enough antifreeze protection with premix; and you won't get the benefits of using distilled water with the antifreeze.

 

What about the flush anf fill kit from prestone? It basically installs a tee at the heater core hose, attach a garden hose, pul the rad cap off and pull the thermostat, reinstall thermostat housing, turn hose on and run car with heat on high for 10 minutes or until water is clean...

I think ten minutes is optimistic; but if you verify that the water coming out is clean...yeah, that works great. I tend to work the throttle, the surging of the water pump as the revs increase tends to help remove the old coolant and loose rust/scale in the bottom of the water jacket. If the water is coming out clean at idle, whacking the throttle open and spinning the engine to 3K or 4K momentarily may swoosh out some crap that idling didn't remove.

 

My concern, Cold water + running engine(heat) = what?

Not an issue. I've done it dozens of times. It's probably best if the engine isn't fully warmed up when you start, though.

 

 

 

 

 

 

 

After you're done refilling with antifreeze and water, (and you're sure the air bubbles are gone, and the coolant is at the proper level) run the engine for half-an-hour, and then TEST THE FREEZE PROTECTION. It's REAL EASY to not get enough anti-freeze back in the engine after a flush.

 

Don't forget to clean out the overflow bottle, and refill with clean antifreeze and water.

Edited May 2, 2011 by Schurkey