Was reading the manual just yesterday, and it said that if you use a cleaner in the system (caustic), to disconnect. If all you're doing is draining the old, flushing with water, then adding new anti-freeze nix, then you should be fine leaving them connected.

Glenn, if you use a cleaner it must not be allowed to enter the water heater. This means that not only do you have to isolate the heater before using the cleaner, you must thoroughly flush the cleaner from the engine system before you reconnect the heater.

Glenn,
I don't know if you've done this project yet, and I don't know why you are doing it, but I tried some stuff last fall that does an amazing job of cleaning and flushing the innards of our engines. It's called Rydlyme (no, I'm not connected to the company in any way), and it's biodegradable. I flushed both the raw water side and the coolant side of my engine, and it completely eliminated the marginal overheating I had beforehand. [URL]http://www.rydlyme.com/home.html[/URL]
Hope this helps.

Tom
How do I flush the systems?

Mike,
On their website I think they show several ways to do it. I used a five gallon bucket, an old 500 gph bilge pump, a couple of barbed hose fittings, and some old hose. For each of the systems (both raw water and coolant systems, but do them one at a time), I disconnected a hose fitting and connected the bilge pump. The idea is to pour a gallon or two of Rydlyme into the bucket, and let the bilge pump circulate the Rydlyme thru the system, dumping itself back into the bucket. I ran this setup for 2-3 hours for each system. When you first start, there is a lot of foaming and bubbling taking place as the solution makes its way back into the bucket. They say that's the Rydlyme doing its thing. Eventually the foaming stops, so the system is clean. The hardest part for me was being patient enough to let the Rydlyme work. Other boat projects, reading material, and a cold one helped.

Tom
Which houses did I disconnect and pump through?

Do I shut the raw water intake first?

I know if you try and start the motor for a few minutes and it dosen't start the raw water will enter the engine cylinders and ruin the engine. Won't this same thing happen if I pump the Redlym throught the raw water system for a few hours?

Thank you for all the tips and suggestions you have submitted to the C36 web site over the years.

Mike,
You should NOT be running the engine while you are doing a flush with a product like Rydlyme. 1) For the antifreeze system, I think I disconnected the hose between the circulating pump and the thermostat. Make sure you take out the thermostat first to allow the stuff to circulate thru the whole engine. Get a piece of hose that will fit on the male nipple you take the hose off of, and get another piece of hose, with a male-male nipple fitting, to fit on the hose you disconnected. Both pieces of temporary hose will have to reach into your bucket. One will just be draining into the bucket, and one will be connected to the bilge pump. It doesn't matter which way the Rydlyme flows. 2) For the raw water side, shut the thru-hull for the engine. Whatever is easier, take off the hose from the thru-hull fitting, or take off the hose from the strainer. Get a piece of hose that will reach into the bucket. The other hose to disconnect is the hose going into the exhaust elbow, whichever end is easier. Same as above, attach temporary hoses to reach into the bucket. For both systems, you are creating your own flushing "loop", going from the bilge pump in the bucket, thru the engine, then back to the bucket. The level of Rydlyme will stay fairly constant in the bucket, but you will be flushing it thru the engine, and cleaning out the cooling system passages. After you have done the antifreeze side, you should flush it several minutes with fresh water. Dump the water, and do it again a few times. Even though it's non-toxic, you don't want any Rydlyme remaining in the engine. After the antifreeze side has been flushed several times, then you should add the proper amount of antifreeze, and re-connect the hoses to their proper places. You don't need to flush the raw water side, as it will flush itself the first time you run the engine. Hope this helps.

This is somewhat of an old post I'mm adding to but, being on the hard, I wanted to change the antifreeze this winter since its been about 5 years.

What's the easiest way to drain the old out and..

I've heard an "orange??" antifreeze is better than the traditional greenish stuff. Anyone have any suggestions?

I don't know about the easiest way to drain it out, I just pulled every low plug I could find and since the M35A and B are different there's not much help there.

But I asked my diesel guy about the diesel specific orange antifreeze vs the green. He said that in his opinion if you change your green stuff every 4-5 years, there's no advantage. He said the orange stuff is better in some engines were the cylinder liners directly contact the antifreeze, apparently it will inhibit corrosion longer in that one instance. He said that situation isn't the case with our Kubota based engines.

Switching from green to orange can be problematic since they're not compatible unless the manufacturer specifically says they are, the newest Prestone premix claims it is. He said I would need to flush the engine with fresh water 2 or 3 times to ensure all the green was totally gone or at least diluted enough. I felt it was more trouble than it was worth and stuck with green, though I did use the supposedly compatible Prestone.

Question for Tom?
This thread started out with a question about wether or not the water heater should be disconnected while flushing? Did you disconnect yours when using the Rydlime? It does appearr by the literature at the website it is safe enough to use without disconnecting.

Thanks Bud.

Seems like changing is more bother and possibly problimatic than worth it.

Gary,
I did not bypass the W/H when I flushed the cooling systems, both raw and antifreeze. Everything I read about the Rydlyme says that it won't hurt any engine components, such as blocks, tubing, fittings, hoses, etc. I believe it works on the "organic" stuff that is in them.

Thanks Tom I think I will get myself setup to do my system in the spring.

[QUOTE=LCBrandt;9218]Was reading the manual just yesterday, and it said that if you use a cleaner in the system (caustic), to disconnect. If all you're doing is draining the old, flushing with water, then adding new anti-freeze nix, then you should be fine leaving them connected.[/QUOTE]

Larry Cooling System M35-B

I have changed anti-freeze and need to top off the fluid level,but the filler cap is lower than the thermostat therefore I have air trapped in the system. What is the best way to make sure that there is no air left in the system?

Regards

Ieuan

You need to 'burp' the system. I will start a new thread to specifically address burping.

Hi, all.

I can understand how RydLyme works in the saltwater loop and why it is needed, but why would you ever need it to flush the antifreeze coolant loop?  Wouldn't it be better to use a regular automotive antifreeze flushing liquid?

One of the reasons I ask is that I tried the RydLyme in the coolant loop last time I changed the anitfreeze (a couple of years ago), but it created a lot of gunk that I never could seem to get rid of, even though I flushed with water several times. 

Part of the problem is that I'm not really sure where all the drain spots are.  The engine manual (M25) talks about drain plugs/cocks beneath the alternator and above the oil filter (port side), but I could never find these.  I only found the petcock beneath the throttle linkage (starboard side).  Contrary to Stu Jackson's admonition (another thread) to NOT use that petcock at all, I've found that petcock to work great for both draining and refilling (the former using an attached hose and the latter using the attached hose  and an attached funnel)...but that petcock doesn't drain the manifold reservoir and there may be other vital drain spots I'm not aware of. 

(Note that my manifold reservoir plug is frozen in place, so I have to pump the old antifreeze out of the manifold reservoir.)

Bottom line is that I need to know how to COMPLETELY "reverse flush" (which is better than forward flush) the coolant system with fresh water and then completely drain the fresh water (to replace with antifreeze 50/50 mix of course).
 

Ok. I have been researching this for a couple of weeks and I think I can answer SOME of my own question. Here goes:

First off, I am not using RydLyme again in the coolant side, as I don't want to go through that mess again. This time I used Peak Radiator Super Cleaner and Flush.  It has good ratings at the auto parts store websites and seems to have cleaned the coolant system well.

I made myself a simple reverse-flush adapter.  See first picture.

I drained all the fluid out of the lower starboard forward petcock (on the engine of course) and then pumped all the fluid out of the reservoir on the port side (coz the drain bolt is old and frozen in place).  Here I was trying to get ALL the fluid out of the engine, except for the coolant in the reservoir.  I'm not sure I got it all but I don't know where else I could drain from. Anyone?

Then after closing the petcock, and unconnecting the clear tube in the second picture from the thermostat housing, I attached the reverse-flush adapter to the clear tube.  You want the other end of the clear tube to remain connected to the hose connection that goes into the coolant pump. This is the key to reverse-flushing because this hose connection outlet is normally upstream of the closed thermostat.  Note that the clear tubes are just temporary!  I was just using them to see what kind of gunk would flow through the coolant system.
...

Then I plugged the SMALL thermostat housing hose connection and unconnected the LARGE hose going into the thermostat housing.

Then I put the large hose that used to go to the thermostat housing into a 5-gallon bucket. This was a bit hard to do.  Hold it with your knee or whatever.

Then I plugged the large thermostat housing hose outlet. Otherwise, even though the thermostat is closed, some water will still come out of it during the reverse-flush.

Then I removed the coolant cap (or what in the auto industry they call the radiator cap) so I could see the water rising in the reservoir.

Then I attached my dock hose to the reverse-flush adapter (again, first pic) and turned on the water - not too much pressure. I was just trying to simulate what the coolant pump would be pushing.

Note that since I (a) had the dock water hose connected to the coolant pump hose outlet and (b) had the large thermostat housing hole plugged, all the water back-flowed through the coolant system and ultimately into the reservoir.  All the gunky water poured out of the reservoir top large hose into my 5-gallon bucket, thus reverse-flushing the entire system.
 
Anyone disagree?  Do you think I got it all, including the hot water tank? This is the first time I've tried this, so it's certainly up for debate... but it seemed to have worked, i.e. reverse-flushed correctly because after I did this for a few bucket loads, the yucky brown water became quite clear.

That was the hard part.  For the rest, I'm pretty much just followed the instructions on the Peak Radiator Super Cleaner and Flush bottle, refilled from the lower starboard petcock with 50/50 mix of Peak antifreeze, and the burped the system.