Hi I did a rad flush last week, I drained in rad as well in the engine body. I when I refill it I was able to fill only 12 litres only 1998 F150, as per manual it suppose to be about 18 litres... what could be the reason... it runs well not getting heat and spare tank has full collent.

 

Its normal not to be able to drain out the coolant completely, gets trapped who knows where. I think your 98 has the same system as my 02, I had alot of difficulty in purging the air out of the system, just keep adding to the overflow bottle if it goes down. Should be good to go.

 

Thanks Bill.

 

Ran into similar issues with my 05. I think the best thing to do after flushing it with whatever cleaner chemicals you used is to...

1. Leave the truck running with heat on high
2. Leave the drain spout open all the way
3. Continually fill reservoir for 10-15 minutes

When I did this with mine, around 8-10 minutes in it looked like pure water coming out and not cloudy from the cleaner and coolant (green).

I then drained about 12/21 quarts (5.4L) that would come out and put 3 gallons of pure coolant in to get my 50/50 mix. It has been running great for the last month. Kinda frustrating that it all just doesn't come out but there are many places in the motor and radiator that it just sits.

 

interesting... so you didnt take out the thermostat to do it? just opened the drain spout?

 

^^ I removed the thermostat so the coolant would start flowing right away instead of waiting for the truck to reach optimum operating temperature which when its 20 degrees F idling takes quite some time (gas is precious!). I put a 12" rubber hose on the drain plug as well so it flowed into my drain pain w/o splattering all over too.

 

excellent. thank you.

 

I know money is tight for everyone, especially around Christmas. The best way to get all of the old coolant out is with a coolant exchange machine. I poured a flush in my upper radiator hose drove for thirty minutes, and stopped at a local Valvoline and had them put in their Zyrex Coolant. I have almost 150,000 miles on the truck with the original coolant. It was a total of 26 Quarts.

 

My hose and drain pan are my exchange machine. I was lucky to get a 55 gallon drum from work so all my oil, tranny fluid, coolant just gets dumped in and brought back to work where the have the means of disposing it. I just drop it off and it gets dealt with. I believe autozone etc would accept fluids like they do used oil as well. Not really sure how you could safely get rid of it. Ends up in the rivers either way!