Coolant Flush Concerns

[SuperII]

Hello all,

Im in the process of flushing out my cooling system because my coolant sample that I tested was nowhere near perfect. So I just drained all the old coolant out of my 6V92T and am looking for a little guidance. From the research I’ve done the engine might need a few flushes with water and then a cleaning solution before refilling with the proper coolant. Is there any concern for idling the beast too long while waiting for the thermostat to open up? I’ve heard that it’s not great to idle them too long and don’t really want to push it. Does anyone have any handy tips or thoughts? Thanks!

[dbsoundman]

Originally Posted by SuperII

Hello all,

Im in the process of flushing out my cooling system because my coolant sample that I tested was nowhere near perfect. So I just drained all the old coolant out of my 6V92T and am looking for a little guidance. From the research I’ve done the engine might need a few flushes with water and then a cleaning solution before refilling with the proper coolant. Is there any concern for idling the beast too long while waiting for the thermostat to open up? I’ve heard that it’s not great to idle them too long and don’t really want to push it. Does anyone have any handy tips or thoughts? Thanks!

I don't have any direct experience here but in general, don't overthink it. You have to do what you have to do to get things serviced, and sometimes that means running less than ideal conditions. Idling is not a good habit in normal usage, but in the context of doing vehicle maintenance it's necessary sometimes.

[SuperII]

Originally Posted by dbsoundman

I don't have any direct experience here but in general, don't overthink it. You have to do what you have to do to get things serviced, and sometimes that means running less than ideal conditions. Idling is not a good habit in normal usage, but in the context of doing vehicle maintenance it's necessary sometimes.

I’m a classic over-thinker so I appreciate your response. I’ll fixate on all the horror stories in my research and then talk myself out of ever doing anything. Thank you!

[Albatross]

It won't detonate on you, if that's what you're asking.

It's spring/summer, and well above freezing most places, so as long as you've got something in the system you should be alright. Fill the rad with water, let the beast idle until it's warm, and just keep chugging water through it until it comes out clean on the other side.

Then add some cleaner and do it some more.
Rinse well, and then pump it full of antifreeze.

Yes, it's quicker/easier if you have "the proper equipment". Yes, that equipment is reasonably expensive. And yes, you can do this with your garden hose if you've got adequate pressure.

[cadillackid]

I flushed mine with a garden hose and a little pump.. I flushed with water while I was replacingthe water pump so it was off.. then I put it back together and started pumping my fresh red new coolant through one of the heater loops.. I wasted a little coolant as it came out a little pink and I kept pumping coolant in until it came out closer to red.. then I reconnected the return line and filled the rad / bottle to the max line.. drove a while.. was low so I topped it off.. and I dont think ive added 1/2 gallon in the last 5 years.. (no issues since then)..

[SuperII]

Originally Posted by Albatross

It won't detonate on you, if that's what you're asking.

It's spring/summer, and well above freezing most places, so as long as you've got something in the system you should be alright. Fill the rad with water, let the beast idle until it's warm, and just keep chugging water through it until it comes out clean on the other side.

Then add some cleaner and do it some more.
Rinse well, and then pump it full of antifreeze.

Yes, it's quicker/easier if you have "the proper equipment". Yes, that equipment is reasonably expensive. And yes, you can do this with your garden hose if you've got adequate pressure.

This sounds like a good plan. The old coolant looks pretty dirty and so I want to make sure Its all cleaned out before pouring new stuff in. Especially because it’s not cheap. Thanks for the info.

[SuperII]

Originally Posted by cadillackid

I flushed mine with a garden hose and a little pump.. I flushed with water while I was replacingthe water pump so it was off.. then I put it back together and started pumping my fresh red new coolant through one of the heater loops.. I wasted a little coolant as it came out a little pink and I kept pumping coolant in until it came out closer to red.. then I reconnected the return line and filled the rad / bottle to the max line.. drove a while.. was low so I topped it off.. and I dont think ive added 1/2 gallon in the last 5 years.. (no issues since then)..

Great advice. I have a garden hose here with really good pressure so that should help. Hopefully I can get by without a pump.

[Albatross]

If, for some reason the capacity of your engine's water pump exceeds the flow capacity of your garden hose, then I would make a 'capacitor' or 'buffer' for the whole system by filling one or more containers with water, lift them into the air above your radiator, and buy a cheap hose to chop up and make a siphon from the water containers down into the radiator. Just keep the hose filling the radiator (through filling the tanks), and you should be plenty alright.

It worked for Archimedes, I don't see why the principles would change for Rudolph Diesel just because you have a different purpose in mind.

[Jolly Roger bus 223]

your local auto parts store should sell a coolant flush and fill kit for cheap where you cut a tee into the heater core line and it has a water hose connection.
also if you know your coolant is filthy then might as well pull the thermostat to flush the system and put a new one in after the flush.
not saying anybody is pushing the limits.
if you need to run it to open your thermostat then do it before you dump the coolant out
if trying without coolant circulating and trying to get the thermostat up to temp. then to me that would be getting into motor damage territory.

[Ronnie]

As far as idling, detroits do not like a lot of idleing, most will have a high idle switch to get the rpms up will sitting.


Do you have a coolant filter? if not you may want to add one.