I recently got a 1994 302 5.0 f150 with 180,000 miles on it and the radiator needed to be flushed since the coolant was brown. I tried to drain using the petcock but it was clogged so I took the bottom hose off the radiator. After draining all the fluid from the radiator I put the bottom hose back on, took the top hose off, and filled the radiator with water until all the coolant had drained from the top hose. I put two bottles of prestone super cleaner into the radiator and filled it all the way up with water. I also made sure the coolant reservoir was filled with the right amount of water after cleaning it out. Then I ran the engine with the cap off while adding water to the radiator. After it was full, I put the cap on and let the engine run for about 10 minutes. I know I didn't drain the coolant from the engine but I would rather not mess with it as I heard the plugs can break. Can I just keep doing this until all the coolant, dirt, and cleaner is out of there? Is there still air in my cooling system that I need to let out?

 

I just did this recently.....I used one of those prestone flush kits that have a few different tee's it along with a spout and some hose clamps. You put a tee in a heater hose and then hook it up to a water hose, then take the rad cap off, turn the water on and start the pickup. Once its going you can crack the rad petcock too. I did that twice and used some chemical flush in the water between the flushes. It seems to have worked very well.

I didn't have a problem with the two plugs on the block. I think you just need to make sure that the allen head sock is seated in the plug the whole way. It did take a bit of effort to break them loose, but after that they were easy to take out and put back in a couple times.

 

Does it flush the coolant in the engine too? If so, only when the engine is running at normal temp, right? I am probably going to need a new water pump. Is the motorcraft pump worth the extra money? I think it is something like $100. I know my way is slow but is there anything wrong with the way I flushed and filled the radiator?

 

Just wondering what plugs you are referring to and where on the block are they located. I need to flush my cooling system too. I saw evidence of a leak at the front of the block, on the passenger side. I need to figure out where it is coming from.

 

I believe it does flush the coolant in the block to a certain extent. As I was flushing the water was pretty warm so it was warming the water, so it would have to be going through the block. You could always pull out the thermostat if you wanted to be sure that it really flushed it well. I didn't use a motorcraft pump when I changed mine. I just went with whatever it was that Eversons gave me. I did go with a new pump over a reman on tho.

The plug on the drivers side is near the rear of the motor on the lower part of the block and the passenger side is towards the front of the motor also low on the block. I used a 3/8 ratchet and I believe a good 1/4" allen head socket. You might want to check the allen head size just to be sure before you crank on them.

 

It will flush the block , you can allway unhook the upper radiator hose from the radiator then put a hose in the rad in the cap hole & let the water pump flush all the water out though the upper hose , it works good....Lew

 

How much water is in the engine block if I just drain the radiator and bypass the heater core? I'm hoping I can just put plain coolant in the radiator and have the total be 50 percent water and 50 percent coolant.

 

The best thing to do is find out what the cooling system's capacity is. Then drain out as much water as you can (assuming that the system has 100% water in it). Then add unmixed coolant (50% of the total system capacity). After that, just top off with water.

 

With iron blocks the guestimation of mixture is pretty forgiving. For the most part too much antifreeze will make things run hotter and too little will of course be more susceptible to freezing. Aluminum blocks are much less forgiving with corrosion being the biggest enemy. Best to use the trusty hydrometer to check the level of coolant so your not guessing.

 

get a prestone flush kit or similar at the autoparts store... 5-10 bucks
Honeywell AFK1T "Prestone" Flush 'N' Fill Kit
the big neck in the kit is to push onto your radiator cap opening and you put the tee in one of your radiator hoses running back to the heater core for a garden hose hook up...

I think that is what you all might have miss is the junk fluid in the heater core... When you flush the truck you need to run the truck engine until hot and keep your cab heat running on high... This makes sure that your thermostat is open and your fluid gets flushed from the block and heater core... after flushing until clear with garden hose water, I usually use light compressed air like 10psi and blow air into the block and heater core (with the truck off of course) to clear the garden hose water out... then refill the radiator and expansion tank with the proper mixture of prestone or other antifreeze... skyfox is right to... you can put unmixed 100% antifreeze in... just do 1/2 of the total system capacity!

this process will ensure you have all the old junk antifreeze out and the proper mixture is back in the block... it has worked perfectly on my vehicles as well as my friends... (25-30 cars and trucks) like i said it works perfectly every time... if you have over 100K you might want to put some alumaseal back in with the antifreeze to plug any small holes or leaks...
Gold Eagle ASBPI12 "Alumaseal" Radiator Sealant

 

The problem is I don't know the capacity of my cooling system because I don't know if I have supercooling or not. My truck is a 1994 with a 302, it has air conditioning and a transmission cooler built into the radiator for the e40d transmission.

 

This is direct from prestone's website


I would say, put in enough coolant to be at 50/50 if you had super cooling. If you end up with more coolant than 50/50. You will actually get more benefits from you antifreeze.

Keep in mind, I just did this to my 302 mountaineer last night and I ended up with about 1 gallon still in the cooling system when I started adding everything back into it.