Bounder: Bounder 8.1 Coolant Flush

[midironman]

I want to flush the cooling system of my 2006 Bounder 35F with the 8.1 vortec. I plan to follow Oemy's technique. A couple questions. Am I correct that the heater core inlet hose is the one I marked with a red arrow? It appears to go from the heater core to the front top of the engine. The hose marked with the yellow arrow runs from the heater core to the top of the radiator. I assume the hose marked red where I should install the flushing tee? I guess I just cut the hose for the tee since I don't have the Evans heater control valve in the hose like Omey does. And afterwards, since the hose has been cut, can I leave the tee in place?

Also, does Oemy's technique do a thorough job? In the past I would run the engine and turn the heater valve open to cycle the flush through. How does his flush work if the heater control valve isn't open? Anything I should do different?

[Flyer15015]

When I flushed mine last year, I just put the heater control on MAX and let her run.

Mike in Colorado

[midironman]

Yeah, that's what I was wondering. Oemy doesn't mention running the engine. Think I will try it that way. Thanks. You think I have the correct heater lines marked?

[Mark_K5LXP]

I am reluctant to do a coolant flush on any engine. It works out with the 8.1 and and motoraid especially like I have, if you flood the system with freshwater you won't be able to add enough coolant to reach the proper ratio. Plus you introduce well/tap water to the system. Not that it has to be "pure" but in my travels I learned you really want to use distilled water.

This is what I do, take it with a grain of salt or call me OCD.

Don't use the radiator drain. If you manage to open it without busting it, it takes forever. Drain the system by removing the lower radiator hose. Easy to get to, and it will be empty in a hurry. I use a 5 gallon bucket on a box right under the opening.

I reconnect the hose, then add ~3 gallons of 50% dex cool and distilled water. That's it. I do this same procedure every year, replacing nominally 50% of the system capacity at every change. After 5 or 6 years I've replaced as close to 100% of the coolant as you need to get. It's cheap and easy to do, no more complicated than an oil change.

Mark B.
Albuquerque, NM

[Flyer15015]

Originally Posted by midironman

Yeah, that's what I was wondering. Oemy doesn't mention running the engine. Think I will try it that way. Thanks. You think I have the correct heater lines marked?

I think so, but the easy way to check is fire her up, put the heater on MAX and touch the hoses. The inlet will be the hotter one. I've insulated mine with foam.
Gets cold up here in Colorado, and we need all the heat we can get in the cabin.

Mike in Colorado

[midironman]

Thanks Mark_K5LXP

Well thats seems alot easier. We just bought the Bounder with only 24k on it. I'm OCD too, and thought I should flush the whole system just so I have a good start. Who knows how it's been taken care of. Maybe not needed? Sounds like just dumping the radiator might get a majority of the junk out. From reading this forum and others, I have decided to stay away from messing with the radiator drain in fear of damaging it.

[midironman]

Flyer15015

Ok, makes sense. That's what I'll do.

[Mark_K5LXP]

When I got my itasca I had no idea when or if the coolant had ever been changed. What I dumped out was a cloudy orange. At least it wasn't rust brown.

This year when I did the dump and refill what came out looks the same as what I'm putting in - clear bright orange. Over the years I've done the same with automatic transmissions, just draining what comes out of the pan and after a few changes a significant percentage of the fluid is new. One can argue it's not as good as a "flush" but it can also be argued it's better than leaving degraded fluid in the system "waiting" for the replacement interval. Once a year and $20 worth of coolant and distilled water is an easy maintenance task, and I end up with fresh additives continuously. That's my theory anyway.

Mark B.
Albuquerque, NM

[Flyer15015]

When we bought our '31 Chrysler Imperial, I did a radiator flush with 2 gallons of "Evap-O-Rust". Pour it in and drive around for a couple of days. Goes in looking like Mountain Dew, and comes out looking like Coke. Worked so well cleaning the rust out, we had to replace 2 frost plugs as they had rusted through.
I've also heard of folks flushing radiators with a good quantity of CLR to rectify the PO's use of tap water for refills.

Mike in Colorado

[midironman]

Originally Posted by Mark_K5LXP

When I got my itasca I had no idea when or if the coolant had ever been changed. What I dumped out was a cloudy orange. At least it wasn't rust brown.

This year when I did the dump and refill what came out looks the same as what I'm putting in - clear bright orange. Over the years I've done the same with automatic transmissions, just draining what comes out of the pan and after a few changes a significant percentage of the fluid is new. One can argue it's not as good as a "flush" but it can also be argued it's better than leaving degraded fluid in the system "waiting" for the replacement interval. Once a year and $20 worth of coolant and distilled water is an easy maintenance task, and I end up with fresh additives continuously. That's my theory anyway.

Mark B.
Albuquerque, NM

I do the same with transmissions because my mechanic does not recommend flushing them, can't remember why.

[midironman]

Originally Posted by Flyer15015

When we bought our '31 Chrysler Imperial, I did a radiator flush with 2 gallons of "Evap-O-Rust". Pour it in and drive around for a couple of days. Goes in looking like Mountain Dew, and comes out looking like Coke. Worked so well cleaning the rust out, we had to replace 2 frost plugs as they had rusted through.
I've also heard of folks flushing radiators with a good quantity of CLR to rectify the PO's use of tap water for refills.

Mike in Colorado

I read somewhere that coolant system cleaners aren't recommended for the vortec, something about seals. Not sure id that's really true.

[midironman]

This is a pic of the radiator fill neck. All that black stuff around the neck and tube worry me. Don't know if previous owner added something to the coolant like a leak stop? This is the reason I want to do a flush. But I will probably just dump the radiator and refill. If the coolant looks ok, stop there. The engine runs good and doesn't overheat. I do smell coolant in the hood area when it's started though, but I can't see any leaks.

[1972VWbus]

Originally Posted by midironman

This is a pic of the radiator fill neck. All that black stuff around the neck and tube worry me. Don't know if previous owner added something to the coolant like a leak stop? This is the reason I want to do a flush. But I will probably just dump the radiator and refill. If the coolant looks ok, stop there. The engine runs good and doesn't overheat. I do smell coolant in the hood area when it's started though, but I can't see any leaks.

Take a close look at the seal on the radiator cap. That could be from it. Does not look like any 'radiator stop leak' I ever seen.

Talking of 'radiator stop leak' the only one I know of that works quite well is called...Irontite All Weather Seal

https://irontite.com/p/8197-all-weat...al-pint/v/8197

[1972VWbus]

With a flush one will get nearly 13-14 qts out if you pull the lower hose. That is what I measured when I drained mine via the lower hose.