Leaf_Chaser

Just ordered a new radiator and getting ready to replace it in a 1995 Ford F150 XL 4.9L V6 standard transmission.

A guy I was talking with said that I shouldn't worry about flushing the system and engine because a truck this age and this many miles (176,000) would cause more harm than good. He said that an engine flush would start a domino effect by loosening all the stuff in and around the water pump causing leaks and on other parts. He recommended just draining the radiator/hoses, put the new one in, and filler 'er back up.

Any opinions on this?

unit505

I call BS! If there are leaks waiting to happen, you need to find them now. Otherwise, your new rad is only a bandaid. Takes very little time to completely flush the cooling system and pressure test it. I guess in theory you could find a head gasket leak or cracked head, but highly doubtful.

Just call me Sean

iTrader: (1)

Sounds like the guy you were talking to isn't too bright.

Crownman

Once you have the radiator out take out the thermostat and put the housing as well as the upper hose back on. Then shove a garden hose into the upper radiator hose and turn the water on all the way. This will back flush the system just fine. Don't boether with any of the flush additives or any of that stuff. Spend that money on a new thermostat & gasket.

fltdriver

Pull the two hoses off the water pump going to the heater core and flush it separately from the rest of the system. As for the additives, up to you, but I changed the coolant in my 10 year old convertible recently, flushed it as good as I could, got it filled back up and decided I should have put a flush kit (which I REALLY recommend, makes life easier for $4 at walmart- Prestone brand). So I drained the fluid back into the bottles so I could install the kit, decided I should test the Prestone Chemical Flush ($4 as well from Walmart) to see if it works since I had just flushed it. I ran just water and a bottle of chem flush for 3 days, each day making a 50 mile round trip (20+ highway, then stop and go traffic, sit for a couple hours, then 20+ highway back, then stop and go traffic, sit overnight) On the 4th day I drained the water/chem after a short drive to open the Tstat and get everything pumping, you wouldn't believe the stuff I got out of my system (I got a decent amount from the first garden hose flush too). Never had a problem with the car overheating or not blowing hot air but she runs cooler and I get sweated out by the heater, just like when it was new. I would say I probably got more with the chem flush than I did with the garden hose just 3-4 days prior.

I would recommend replacing anything that looks like it's original (or just old and doesn't have much time left) hose wise. New tstat and gasket for sure as well as the $4 Prestone Flush kit, I would honestly do the water pump ($$25 on rockauto - if not the pump at least the gaskets, unless it's been done in the past 5 years). As good as the Prestone Chem Flush works I'd also thing about the heater core ($20 on rockauto).

I would say your "friend" has a don't fix it until it won't work at all mentality, cooling system is easy to replace parts so why not expose any potential leaks now instead of in the middle of something important. I could understand the same logic on the crankcase/lubrication system for the engine, just because it's more labor intensive to replace most parts, but the cooling system is all exposed and accessible without really removing anything else, hell you are doing the hardest part anyway.

Leaf_Chaser

All excellent information, guys. Thank you very much. The guy I was speaking with was one of the counter helpers at AutoZone where I live. When I asked if they had the Prestone cleaner for flushing, that's when he said it's "not worth doing."

I'm like you guys - I'd like to go ahead and flush it all now and if something gets exposed, might as well knock it out now. I'm gonna do the flush/back flush. When I bought it a few months ago, I had a mechanic do a tune up on it (before I learned that most of it could have been done myself with a little help from forums like these and YouTube). He replaced the thermostat and put a new radiator cap on it but the radiator wasn't leaking back then. So this radiator replacement will be a first for me.

One last question - since I've never replaced a radiator - how much coolant do I put in? I know to fill it to the top, massage the top hose, keep running it and topping it off, etc., but do you start off with 1gal of concentrated coolant and 1gal distilled water? Or 2gals each then top off as needed? Just not sure.

Again, thank you guys for the advice and help!

Chris_1

iTrader: (1)

You want to keep the coolant at a 50/50 mix - more or less, it doesn't have to be exact.
A jug of 100 % and a jug of water. Then mix 50/50 into the jug you just emptied and go from there.
Heat it up and cool it right down a few times before you drive it around - to get the air out.
Use a flashlight to check for leaks. You should be fine.

Manuellabour247

^^This. Just buy 3 jugs of 100%. After the first jug of straight coolant, put water in it then use the second jug as a premix jug. Pour half into the first jug then fill both the jugs with water. The third jug should be just to top it off. And definately do the heater core separate. A good garden hose flush will make a world of difference.

fltdriver

You won't need much more than 2 gallons of 50/50, like they said get 100% and dilute it with distilled water (much cheaper than buying 50/50).

When you have it emptied put in the Flush Kit (prestone) it allows you to not only flush the system without it going all over but when you are refilling you leave the cap slightly open and fill until it starts to comes out, close the screw cap then top the rad off. You will still have to "massage" the upper hose once or twice for the air in it but that gets the majority of the air out without even starting the truck. When I flushed mine I only had to top off the cold fill tank (to the line) once.

Crownman

As a wise old man would say... Well theres your problem right there.