[DogKnots]

Anybody replaced / re-cored their generator radiator?
I dropped mine at the shop last week because it had a little leak where the tank attaches to the core.
I asked Newell about a new radiator and they didn't have a source for one (Kohler 20KW).

[encantotom]

i took mine out and had it cleaned and the leak on the neck fixed. cost like 100 bucks or something like that. no issues.

not sure why you would need a new one unless it is damaged.

tom

[DogKnots]

If the core is eroded internally, it needs to be re-cored which is over $400.
I thought a new radiator may be less money, but I'm doubtful.

[encantotom]

Understood but surprised the core would be so corroded.

My Genny has over 8000 hours

Tom

[HoosierDaddy]

I'm thinking radiator core life is affected greatly by the frequency of flush and replace maintenance. I'm not sure what Newell recommends but a flush/coolant replace every other year would be good practice.

[bestgenman]

The coolant PH is the most important factor in radiator longevity besides freeze point.

---

Forgot to add,  Ph includes Molybdate & Nitrite balance.

[DogKnots]

Got the radiator back on Thursday. Hoping to re-install it today before the football shenanigans start!
He removed the leaking tank, cleaned (rod out) the core, soldered the tank on correctly, and told me it was in good shape otherwise. Time will tell...

[encantotom]

It should be fine

Tom

[DogKnots]

I replaced everything and I'm back running.
I made some videos of the process but I do not know how to attach them to this message (let me know how please!)
I had a few hiccups along the way though. I'll tell you and/or you can see if I get the videos up. Hopefully you all can avoid my pitfalls and have a better idea what to prepare for if you do the same job.
The start to my problems was that I tried to filter / reuse the coolant. I eventually flushed the system and replaced with new pre diluted coolant which is kinda a blessing in disguise.
I allowed the old coolant to sit in a bucket and all the sediment collected on the bottom of my bucket. After a few weeks when I went to replace the coolant, I decanted the clean fluid off the top and into my radiator through a filter (fine knit rag). I left a little bit of the old coolant with the sediment in my bucket to test compatibility with new coolant. Epic failure here. I wanted to use "pure" undiluted coolant because I previously added a little water to the radiator and I wanted to get back to approx 50/50 blend. The new and old fluids mixed perfectly in my test bucket but when I put it into the radiator, a precipitate formed in the radiator! The precipitate was floating / suspended soft white stuff in the coolant. That's when I decided to start over and do this job right. I wasn't sure if it was a chemical reaction, gunk in the system, or flux from soldering the tank on. I now think it was a chemical reaction, but it wasn't worth the worry.
I removed the thermostat and flushed both the block and the radiator completely, drained them, and refilled with 50/50 premixed coolant. Mine is a 20kw kohler with a Yanmar motor and it took about 2.5 gallons. The details of flushing are easy to see in the video but the gist was that I flushed both parts both directions. I wanted to "float" the debris out of the radiator so I had to fill it from the bottom and let it flow out the top. I used tap water for the flush and the city uses a reverse osmosis plant. I thought about using distilled water but I was able to flush much more thoroughly using tap water and it's hard to beat RO water.
The upside to this debacle is that I don't have to worry about the coolant for a long time and we've got a couple big trips planned for this year.
The last little problem occurred when I was running the generator with it extended. I was letting it warm up after I filled the system. I expected to burp the system as the thermostat cycled. I did not need to burp it at all as it completely filled with the engine off and cold. The blower motor (passenger side forward most bay) cut off after running it up to temperature. That happened around sundown so I just cut it all off until today. After sitting overnight it's working fine, with the only difference being that I've got the generator in (hush box closed). I've had it running 3 hrs now and it's rock solid at just over 160°. I'm thinking the electric motor maybe runs too fast without back pressure and overheats...or I've just got a motor that's about to go bad. Either way I've got a spare motor that I carry everywhere just in case.
Last interesting item was noticed when I used the aquahot electric to load the generator. When doing this I noticed that on one leg I'm pulling about 12 amps and on the other leg I'm pulling about 30 amps. I thought the electric element was 240 volts...maybe half of mine is bad? Everything works fine, so I'm not overly concerned rather more interested in learning the systems completely.
I plan to add an overflow tank system to the front of the air shroud instead of just having an overflow that goes on the ground...it'll also keep the system full and is a quick additional visual check point.

[rheavn]

"Last interesting item was noticed when I used the aquahot electric to load the generator. When doing this I noticed that on one leg I'm pulling about 12 amps and on the other leg I'm pulling about 30 amps. I thought the electric element was 240 volts...maybe half of mine is bad? Everything works fine, so I'm not overly concerned rather more interested in learning the systems completely."

A couple of things may account for one leg showing more amps than the other.  The 240V electric AquaHot element is pulling 12 amps per leg.  Now add in the amps of the 110V electric AquaHot element on one leg and probably your battery charger on the same leg.  I have seen this type of split on my coach which is similar to yours.