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how to drain coolant ?

83K views 83 replies 5 participants last post by  princesspri 
#1 ·
the previous owner just did the water pump, and he replace coolant with green type, and by look at the reservoid cap, i can tell it been mix with dex-cool. I want at least drain the radiator and refill it with prestone green type, since he already using green stuff. I craw under the truck, but I cant find the drain thing from the radiator, seem like everything is on in the way. any idea ?
 
#2 ·
I would not only drain the old fluid, but I would totally flush it out and put the dexcool back in. Start by pulling the lower hose and letting most of the coolant drain. Then, put the lower hose back on and fill it with regular water. Then unhook the upper ho0se at the radiator and start the truck. Turn your heat to hot (you do not have to have th fan on). Run water from the hose into the coolant fill hole in the tank and keep running the engine untill only clear water is coming out of the top hose. Once you are sure you have flushed all the coolant, turn the truck off and again take the lower hose off to drain the water. Reconnect both the upper and lower hose and fill it with dexcool (about 1 1/2 gallons) and top it off with water. You can check your owners manual to see what the capacity is for your cooling system. You want a 50/50 mix of water and dexcool (this is how to do it with the full strength dexcool, not the premixed dexcool).
 
#3 ·
Look like sunday job. So I need 2 gallon of dex-cool ( not the 50/50 mix one right ? ), btw when you say fill with regular water, u mean garden hose water ?
 
#5 ·
doing all this when engine is stone cold right ?
 
#6 ·
btw, last couple day I been checking my coolant, when cold it stay at cold mark, and when hot it still stay at cold mark, btw is their anyway I can take off the reservoid and toolbrush inside it, its kinda brown, mabe because all the dex-cool stain on it.
 
#7 ·
The engine does not have to be cold, just so long as it does not have any pressure when you remove the cap, so you will not get burned. You can take the reservoir off and put some small ice cubes in it and shake it really good and that will help knock the sludge out of where you are not able to reach with a brush.
 
#8 ·
thanks for the tips, after read your how to, i have more confident of doing it. btw I seem cant find the drain plug on radiator, if I find out, should I leave it open with low hose dis connect ?
 
#10 ·
when pull the low hose, i disconnect from the radiator side or engine side ?
 
#12 ·
You guy think I can run like this ( green coolant ) until this sunday or next sunday safe ? im only drive 15 mile a day. I know I might be paranoid about running green coolant on gm car. really busy and I need this truck every day drive.
 
#14 ·
Machster69 said:
U can run jus water too, done it! :) but ide run red if you can!
cheer ! thanks, i will change it out asap when I have time, just got the truck and I want it to be depenable as much as possible by doing complete maintaince it, time/job is what holding me back :)
 
#16 ·
When I clean the truck bed, I saw 2 kinda full coolant, it autozone full strenght coolant, regarless of what its, imma flush it out soon

btw the 2000 model radiator do not have fill cap on radiator right ? only fill on the reservoid.

2, is their a bleeding screw anywhere on these type of truck ? I want get air out the system ? or leave the cap open over night ?
 
#18 ·
There is not bleed screw on these engines. You can just run the engine so that the thermostat opens after filling it with water and coolant with the cap off. Just keep topping it until all the air is prurged. You can check it the next couple days after you have driven it and let it cool to make sure no more air is purged and you do not have to add any more coolant.
 
#20 ·
ASTE25 said:
Machster69 said:
If theres coolant in the bed... Its prally been leaking... Might wanna check that!
That would be one hell of a leak! I think he meant he found the old containers the previous owner left in the bed after filling it the last time.
thumb up !
 
#21 ·
sparkplug said:
When I clean the truck bed, I saw 2 kinda full coolant, it autozone full strenght coolant
Lol thats what i was getting at? If hes adding coolant, there must be a leak! Did i type that wrong? Are you messing with me! Ok let me rephrase, he found two jugs of coolant in the bed. I was saying there was two jugs because there must be a leak bc first, only 1 jug is needed! Water is added to that for the remainder!
 
#22 ·
Machster69 said:
sparkplug said:
When I clean the truck bed, I saw 2 kinda full coolant, it autozone full strenght coolant
Lol thats what i was getting at? If hes adding coolant, there must be a leak! Did i type that wrong? Are you messing with me! Ok let me rephrase, he found two jugs of coolant in the bed. I was saying there was two jugs because there must be a leak bc first, only 1 jug is needed! Water is added to that for the remainder!
He just did the water pump, it look brand new, I guest it come from that.
 
#24 ·
guys, the coolant level when it cold, it stay at cold level, and when it hot, it still stay at cold level ? no matter what temperture, it still say at same level.
 
#26 ·
update : after work today try take off the atf drain plug, but give up, so I doing the coolant flush,
1: dis connect the low coolant hose ( radiator side ), and most coolant out,
2: stick the garden hose into the coolant fill reservoir and fill it up
3: dis connect the upper coolant hose and let all coolant came out until it clear water came out,
4: connect low coolant hose and leave the upper disconnect and stick the garden hose into the reservoir and turn on engine, turn on the heat and I stop until clear water came out upper hose
5: dis connect lower hose and let all water out
6: hook upper and lower hose back into radiator and fill it with dexcool, about 1 gallon of dexcool and turn engine on, idle for 20 min, coolant burp back out the reservoir and after it stop i quickly fill it up with water ( I bought extra gallon of water ), fill it back to cold mark. leave cap open over night

1 question, My truck have no heat the entire time, I turn the fan all the way to # 5, and the knob to hot, but entire time the truck idle, it keep blow cold air, but no hot air. any idea ?

btw is the reservoir having some kind of drain hose incase the reservoir over fill ? the other day I over fill the reservoir and today I was under the truck check for leak, i saw 1 tiny drop of green coolant stick stick to the area next to oil filter. Im scare it have a leak some where.
 
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