Keith,

It's pretty straight forward. Drain your coolant and use your removed hoses to make exact copies. I'm sure you are going to do this but make sure your hoses are wire reinforced and rated for your cooling system.

You will also find different sized hoses in the same run such as the 1" hose running from your engine coolant reservoir to your 5/8" Heat Exchanger and likewise back from the 5/8" HX to the 1" coolant pump. While you are at it I'd replace the two raw water hoses. My PO forced 1/2" hoses onto the 5/8" hose barbs which I am sure was part of my cooling problem. I'd also suggest replacing all of your S/S clamps. If your engine was like mine the hoses and clamps might be almost original equipment...

Last thing do some research on burping your engine after you refill the coolant. Watch the temp gauge after you restart your engine making sure to not let it over heat...good luck...

Chris

BURP (oh, excuse me!)

Here's how: [url]http://c34.org/bbs/index.php/topic,4518.0.html[/url]

Wire reinforced hose is very important, as I understand things, in order to stand up to the rigors of the marine engine, so I would be VERY cautious about using automotive hoses.

I have an '89 C36, purchased in 2007, and the hoses were among the first things I replaced, with marine grade hoses and new clamps.

Also: be sure and check places where there is existing evidence of rub areas or near burn throughs, if any. You will want to take steps to somehow protect these areas further.

Interesting timing, this ties in with my other thread on the HE anode. I decided to do total overhaul on cooling system so am replacing all the hoses as well. Agree with Laura, the hardwall wire bound hoses are essential especially on the suction side to prevent collapsing.

It's impossible where I am to get hardwall hose at auto parts stores, only place that had them was a truck dealer and they only carry big stuff. I called the Universal dealer up here and ordered it from them. They told me they no longer stock the formed 90 degree hoses but that the hardwall wire bound stuff they carry can be formed easily in tight 90 bends without kinking.

Our engine has a short piece of 1", a bunch of 7/8", some 5/8" and two little short pieces of 3/8" that go from the water pump to the hot water heater 5/8" lines. The only ones they can't get wire bound are the 3/8", they are sending fabric reinforced ones instead. The ones on there now look like they're about to burst!

We had no leaks in any hoses, but they are all original and 15 years is enough. I'll keep them as spares. Putting all new clamps on as well.

Interesting phenomenon, every fall when the weather goes cool most of the joints leak and you can put 4 or 5 turns on every clamp. Vibration, heat/cool cycles I guess.

Also interesting, the big antifreeze drain plug on the starboard side of the block works its way loose every year and then weeps antifreeze. There's no gasket under it. I am going to replace this one and use blue Loctite to see if that will solve that problem. Maybe someone else has experienced that and has another solution?

Thanks for the detailed post on the hose sizes; I need to tackle this task, probably next spring.

Did you just buy lengths of each size and cut to fit? If so, could you post how much of each is needed to do the job?

I'm assuming you have an M35A, which is the same engine in my '97. If I recall correctly, the manual shows the antifreeze drain plug on the [I]port[/I] side; I've looked for that thing and not been able to find it. You're saying it's on the starboard side? About where is that thing? I need to drain/change the anti-freeze, which someone posted can be done from the water heater. I'll change the anti-freeze when I swap out the hoses, but I'd sure like to be able to drain it from the engine from time to time, even if it doesn't get 100% of it (an oil change doesn't get 100% either).

Thanks again for the info.!

Gary, yes M35A. I ordered 2' of 1", 4' of 7/8", 2' of 5/8" and 2' of 3/8" and I am just going to cut it to size using hacksaw and side cutters.

From what I can see in the parts books, these engines can have two different layouts for the hose that goes from the HE up to the water pump. One of them had 7/8" all the way. The other, that we have, goes 7/8" from the HE to the front of the engine where it goes into a copper (brass?) elbow that has 7/8" on one end and 1" on the other end. Then there's a 9" piece of 1" that's got a 90 degree bend in it that goes to the water pump. So that's why I needed 1". The long piece of 7/8" in this assembly is 23" long.

There is 1 piece of 7/8" that's about 8" long with a 90 in it that goes from the water flange thermostat housing to the exhaust manifold at the front. Another piece of 7/8" that's about 9" long that goes from the back of the exhaust manifold to the HE, on our boat this one was not wire bound and it is very soft and spongy, not good feeling at all.

The 5/8" is for the raw water pump to the heat exchanger. It is 24" long. I'm not changing the really big line from the strainer to the water pump, it is looks new and feels very solid.

The 3/8" ones go onto the nipples at the water flange and connect to nipples in the 5/8" lines that go to the water heater. The dealer got that 3/8" measurement by checking the crossover tube they had in stock that normally is there.

Also not changing my 5/8" lines to the hot water pump, they look new. Also not changing the 5/8" line from the HE up to the vacuum break and down to the mixing elbow that also looks new. These are all Shields green stripe hose which is very good I am told. I'm just going to buy about 20' of this stuff to take with us in case it becomes necessary to fix something in those areas.

The drain plug I referred to is on the starboard side if you're looking top down at the engine facing the front. Which is probably backwards to what I should have said. If you're standing at the front of the engine looking back, it is on the port side, low down on the block and below the fuel injection pump. It's a big bolt looks like maybe 1 1/8" pipe thread, it has a 30 MM head, and should have a petcock in it to drain the antifreeze but ours has no petcock on it they've just screwed a plug in there. Might add a petcock would be handy to have.

The antifreeze in ours looked very clean so I'm not going to drain the water heater either.

What started all this was the solder joint of the rad cap neck to the exhaust manifold started weeping antifreeze. It obviously had been mickey-mouse fixed before. My friendly local rad shop that also happens to clean diesel tanks sent a guy up with a torch and he unsoldered the old neck and soldered a new one in. But to do that I had to get all the antifreeze out. So it seemed a good time to do the whole nine yards, or most of the nine yards. He did a very thorough job of it, cast iron is had to work with and it needs a skilled guy and I liked what I saw. Hopefully it will solve this problem but we won't know now until spring.

All this is in preparation for our planned run south next year. Hopefully we can meet some folks from this forum in person when we do that trip.

thanks; this thread got copied/pasted into a document in my boat 'how to' folder.

My anti-freeze looks nice and green and tests fine with a tester, but, as I understand it, anti-freeze looses it's anti-corrosion properties after a few years. Hence my desire to change it out. I've always had to add a good bit every year, so it gets a partial refresh, but I've not yet drained/replaced it all.

I got a good education in the need to change anti-freeze in my 1st car, a new '73 Toyota Celica, which I had for 13 years (totaled in an accident). One winter, the heat wouldn't come on. Fooled with the heater adjustment and eventually, after several very cold trips back and forth to college, it came on. Looking in the radiator, it was quite brown. I drained it all and it came out like mud, 'blop blop blop'. Had to use a garden hose to get it out of the heater core. I then used radiator flush to clean out the whole system. Never had the problem again, but I changed the anti-freeze every few years, regardless of how it tested.

Don't want to go through that on the boat, that's for sure.

This fall I had a diesel mechanic look at and listen to the engine just to make sure it wasn't doing anything weird or had any odd sounds. He pronounced it healthy, other than the obvious rad leak issue.

I asked him about the diesel specific antifreeze, whether it was worth using or not. He said that it does have better anti-corrosion properties, but it is incompatible with the green stuff and you would have to fill and empty the cooling system with straight tap water at least 5 times to get rid of most traces of the green stuff. Given that, and the fact that I've never seen anything but green stuff in boat diesels, I decided to stick with the green stuff. There are some additives you can get that are supposed to restore the anti-corrosion stuff in antifreeze but I've never used them.

It's a wonder the old Toyota was still running! Takes a licking and......

Bud, I have been told that we must use the marine specific antifreeze or risk a fine (how they, whoever they are, wold discover that out).

BTW, on your way sounth stop in North Carolina and see us. There are lots of 36 members here.

Glenn, we are certainly hoping to connect with some folks from this forum on the way through, it'll be a treat to be able to visit with fellow C36 owners, these boats are pretty scarce we were are from so we don't get the opportunity to do that around home.