hey folks,

i'm installing a new radiator in my '78 F150 tomorrow to replace an old cracked one (currently have to add ~1/2 gal water every time i drive). i picked up a bottle of flush solution on the theory that it would make sense to clean out whatever's in the lines before starting fresh... also have one of those flush kits that splices into the heater line, just not sure which process makes the most sense:

1) splice in the flush kit, run the flush solution for a while with the old radiator, backflush using the kit, let everything cool down & drain, then install the new radiator;

2) run the flush solution for a while with the old radiator, let it cool down & drain, pull the upper radiator hose, run water straight from garden hose into radiator 'til upper hose runs clear, then install the new radiator (as recommended by radiator shop);

3) drain & pull the old radiator, splice the flush kit into the heater line, block off one end of the heater line & backflush; install new radiator & return unused flush solution;

4) drain & pull the old radiator; install new radiator; call it a day.

5) something else?

...additional factor: PO attempted to repair the old radiator with JB Weld, once in a while I find chunks floating in the tank when adding water. Would like to avoid driving these further into the system & clear out whatever's in there now.

 

well, I forgot to bring the flush kit, so the process was 1) drain; 2) use flush solution per instructions (run w/ water, drain, run straight water, drain); then installed the new radiator, only to discover that the trans cooler lines needed different NPT fittings, so I'm finishing tomorrow.

fun fact: if you're scrambling to find something with which to plug a trans cooler line and don't have a couple of pencils handy, cigarette butts work nicely.

 

LOL, that's a good tip!