Has anyone installed one of those flush and fill kits from Prestone? It it supposed to help flush the cooling system. Also, anyone use Prestone antifreeze?

Why hasn't anyone answered? Was this a dumb question? Sorry to be a pain but I was considering flushing the cooling system.

Isn't the coolant rated for 100k miles? :confused: I noticed you have an LB7 but you've posted on the LLY forum, threw me off at first to. Seemed awfully early to being flushing an LLY.

No need to flush until you have to. Are there other factors in play here? Does the coolant look rusty or black? JJ :)

I usually drain the system via the radiator petcock,close it back then remove the upper radiator hose from the radiator. Afterwards fill the recovery tank and radiator w/ distilled water. Then with the engine running and heater turned on continue to maintain the level in the recovery tank w/ distilled water (keeping the system full) untill the water flowing from the removed upper hose runs clear. Afterwards open the petcock to drain out the water to make room for the dex. Close the petcock and replace the radiator hose to the radiator and fill with pure dex via the recovery tank untill you have added 50-60% of the systems capacity. Top off w/ distilled water and button up the recovery tank cap. The fluid will mix afterwards. Done deal!

Don't forget the bleed valve! IIRC there are explicit instructions in the owners manual for doing this. They actually did a pretty good job with that section IMHO. JJ :)

Yeah, I accidently posted this in the wrong forum (followed a link and got confused). I didn't know how to move it and didn't want to post twice. I read the replys and it seems that the flush and fill kit does the same thing without having to remove hoses etc.

Just thought I would get some opinions.......

Actually there's really no need to bleed the ports located on the thernostat housing. A couple of RPM cycles will move the air right out. This small amount of air has only one direction to go and it will quickly exit.

On Edit: The flush fill kit will require the cutting of the heater hose and will require tap water (garden hose) to complete the flush so scale building minerals typical of tap water will be left behind after draining. IMO the only gain from the flush and fill kits are Prestone's bottom line. The theory of back flushing will only short circuit the flush when the T-Stats are closed. The T-Stat will need to be opened to flush all cooling circuits.

Mods, thanks for moving. ):h Next time I will pay more attention.

abear,
I thought it was a closed system. Where does the air go?

abear,
I thought it was a closed system. Where does the air go?
The air will make it's way to the recovery tank. :)

The theory of back flushing will only short circuit the flush when the T-Stats are closed. The T-Stat will need to be opened to flush all cooling circuits.
We used to have a local steam cleaning place that used to back flush with HOT water so t-stats would stay open and they even shot a little pressure in to loosen the crud, used to work good till the enviromentalists complained about the place and it was closed due to a lack of funds to install a $100,000 water recovery/seperation system. :(

You should use the bleed screw. A big air pocket might not let the thermostat open.
Den.

So it doesn't seem that the Flush and Fill kit is the best way. Is there a "How To" or is it a pretty simple proceedure? I have done it on previous trucks and the wife's minivan.