[heavyhaulerss]

what is the correct way to flush the entire cooling sys on a big truck. to be specific a detroit engine? can a person do it himself, or is this something that needs to be done by some expert with specific knowledge of the cooling sys? my temp is rising faster than used to & if left idling temp climbs lil faster than used too. everything on truck o.k. new water pump, new thermostats, new hoses, head gasket o.k. but never had radiator or cooling sys flushed. thinking this may help?????

[allan5oh]

Take a look at the bottom of your rad. Is it all rusted? Older rads that rust do not cool as good. Maybe get that sucker changed, and flush it while they're at it. I really doubt just a flush will help.

[possum squat]

If it is like an auto system, then flush when you change coolant. Just keep running water through until it starts to come out clear. Then close the drain and fill with coolant.

I dont think the commercial products "flush in a can" are recommeded, usually. They might do more harm than good.

I defer to the others wisdom...

[possum squat]

might consider washing the rad from the outside, cleaning bugs and dust

[bob h]

quote="heavyhaulerss"]what is the correct way to flush the entire cooling sys on a big truck.

remove thermostats, drain the rad, and disconnect upper and lower rad hoses.

run water in through the lower rad hose and out the upper hose to backflush rad, and then the same with the engine until water runs clear

reverse the flow (from the top hose to the bottom) again at the rad and the engine until water flows clear again

to be specific a detroit engine? can a person do it himself, or is this something that needs to be done by some expert with specific knowledge of the cooling sys?

a person can do this... can you? that question is difficult for us to answer

my temp is rising faster than used to & if left idling temp climbs lil faster than used too. everything on truck o.k. new water pump, new thermostats, new hoses, head gasket o.k. but never had radiator or cooling sys flushed. thinking this may help?????[/quote

i doubt it will help. how about measuring a temp drop across the radiator at operating temperature? do you lose any coolant? has the coolant been tested? does the coolant expansion tank ever overflow?

[heavyhaulerss]

no loss of coolant. no coolant coming from overflow. had coolant changed & replaced 8 months ago. i also went from 190 thermo's to 180. that did help a bit. i have a manual fan switch on dash. i use it when needed. it though takes longer to get temp down than used to. just hit 1 mil mi's, so this is not a big prob considering the mi & age of truck. just trying to learn a lil & to fix.also put sensor that sends signal to temp gauge at thermo housing.something is causing temp to climb higher & faster than norm. if i'm going up hill empty i have to hit manual fan. temp gets to 205-210 from 180-185 this seems too much too fast with no load on it. all i have to go by is how the truck has performed over the last 7-8 years since ive had it.right or wrong it's one of those cases where you know your truck & you know it's acting different than it used to. thank you lot's.. troy

[allan5oh]

Definitely rad from what you're talking about.

[Dejanh]

Radiator brother, radiator...900 bucks + the labor i say its well worth it if youre planning to keep the truck !

[Bobby]

You didn't mention replacing the radiator cap ?
If it's not holding pressure it will cause the truck to run hotter.... but your description sounds like it's more than the just the cap.


Just to add: When I bought my 01 KW ( has a big assed 1400+ sq. in. radiator) it was in the summer.. a hot one... but the truck seemed to get hotter on hills than I thought it should for a truck w/low miles and in good shape.
It was the radiator cap...plus it didn't have a sight glass to see the coolant level..so I added one... and it took a gallon of coolant to bring it up to the sight glass :roll: so much for looking down the fill hole and guessing the level. The bad cap was also causing it loose coolant. It's cools fine now.

This KW doesn't have a recovery tank for the radiator ? I was wondering why ?

[jorlee]

Originally Posted by Bobby

You didn't mention replacing the radiator cap ?
If it not holding pressure it will cause the truck to run hotter.... but your description sounds like it's more than the just the cap.

I second the radiator cap. Helped neighbor drive truck for a few days so he could finish harvest. Idling the truck would run hot, and was hotter than normal. Checked the cap out and it wouldn't hold any pressure, new fixed it no more heating when idling.

Take the simpliest thing first then move on. If it's the radiator your going to need a new radiator cap anyhow so try the simple things first.