Draining Coolant, Any Tips?

[Guest]

This is for future reference, but the worst job I do on my boat is draining the old coolant. I get waht I can from the heat exchanger and the skin tank bleed cap using my Pella. There is no drain tap on the skin tank, so I have to pull the bottom hose, which is a messy business requiring much mopping. I wondered about putting a reducing tee in the bottom hose with a valve on it, so that the last few litres can be drained from the skin tank by connecting my Pella pump to the valve? Any tips/tricks/ideas welcome. Many thanks.

[Top cat]

Ive got a similar problem so will be interested in responses.

 

Top Cat

[Mike on the Wey]

This is a summary of my recent coolant replacement:

A 20 litre drum of red (5 years) antifreeze was £37 from my local motor factor, compared with £32 for blue (2 years). Well worth it. The coolant capacity of my particular round-stern Sea Otter is 35 litres. I obtained two used drums from a local garage for mixing the new antifreeze and disposal of the old.

 

Draining was easy once I managed to free the bottom hose from the union. A drill-driven pump made removal of the waste coolant from the bilge an easy job. I then flushed and back-flushed until the water ran clear, again pumping out from the bilge.

 

With a deck board across the back rails and the drum of diluted antifreeze thereon, filling was very easy. I used 2 metres of 10mm tube, with a hose clamp as a tap. Steady filling through the "radiator cap" opening in the heat exchanger was simple, and the air purged easily.

 

A 2-hour cruise followed, followed by a half litre top-up and a second check of bleed points. A simple and satisfying DIY job.

[Sea Dog]

This is a summary of my recent coolant replacement:

 

 

I think the OP was trying to avoid draining into the bilge and to avoid breaking the seal on the awkward to reach bottom hose to skin tank connection.

[j04n]

This is a summary of my recent coolant replacement:

 

A 20 litre drum of red (5 years) antifreeze was £37 from my local motor factor, compared with £32 for blue (2 years). Well worth it. The coolant capacity of my particular round-stern Sea Otter is 35 litres. I obtained two used drums from a local garage for mixing the new antifreeze and disposal of the old.

 

Draining was easy once I managed to free the bottom hose from the union. A drill-driven pump made removal of the waste coolant from the bilge an easy job. I then flushed and back-flushed until the water ran clear, again pumping out from the bilge.

 

With a deck board across the back rails and the drum of diluted antifreeze thereon, filling was very easy. I used 2 metres of 10mm tube, with a hose clamp as a tap. Steady filling through the "radiator cap" opening in the heat exchanger was simple, and the air purged easily.

 

A 2-hour cruise followed, followed by a half litre top-up and a second check of bleed points. A simple and satisfying DIY job.

Jesus I think you need to get out more! ......... Changing the coolant was one of the first jobs I did on my boat. With no indication or even clue as to how much the boat held. I like seemingly the other guys saw no alternative but to crack open the lower skin tank hose and drop it into the bottom of the boat. Obviously after checking the coolant, or should I say neat H2O! would be contained. Once drained there seemed to be a lot in the bottom of the boat but not being a good judge of volume I still had no clue. Yes I could have calculated it but you know how it is, once youve started you think there is no need. Anyway, I had bought two 5 litre containers of red(no worries for 5 years, get in there!) antifreeze thinking twice as much as a car must be about right! .......Oh how wrong was I! I then mixed the antifreeze with water, 50-50 and proceeded to fill the expansion tank which was in the wheelhouse and holds about 2 litres? Then climb down under the wheelhouse, free the bleed nut, keep looking up above the floor boards, once the expansion tank was empty, nipped up the bleed nut, climbed back up into the wheelhouse and repeated the process, and repeated the process, and repeated the process, and repeated the process, etc! Needless to say I had to make another 1 hour round trip to the motor factors and bought another 5 litres of antifreeze, thought thats bound to be enough! ........ oh noooooo! several hours later and another 1 hour round trip to the motor factors out of desperation I bought another 10 litres of antifreeze. Thinking at least I might be able to take the second one back! Oh no it took the lot........ Have you any idea how many times I climbed in and out from under the wheelhouse!!! ...... and how ridiculous I felt thinking the antifreeze mix was going to come rushing out of the bleed nut at any time after only putting around 20 litres in? Anyway in the end it took 50 litres!!! it is now ingrained on my mind, its one of those things you will never forget! .......... I didnt even want to contemplate getting the water out of the bottom of the boat so thought I would console myself with taking her for a spin whilst keeping a close eye on the temperature and coolant level. We set off and all was good. Temperature was rising steadily but nothing to be alarmed at and surprisingly the coolant level was holding. Engine temperature continued rising but coolant level was holding, I was starting to get concerned. The Mrs, who was constantly monitoring the coolant decided she needed a toilet break. A quick glance at the coolant level, all was ok I released her from her post. She cant have even got comfortable when I glanced behind and was horrified to see the expansion tank was empty and the engine temperature was still rising. Fortunately I had a some antifreeze mixture left over which I proceeded to fill back up and return to my station. I hardlies got back to the helm, glanced back and the expansion tank was empty again! Getting a little agitated I was heckling down the boat asking what the hell she was doing and was she not finished yet as I could do with a hand! The smallest things can get so out of hand at times! ........ Anyway the mrs took over the helm while I sorted out the coolant level. It took another expansion tank fill before normal service was resumed and the engine temperature was resumed. I hope I havent broken it!? Anyway just as I was relaxing and returning to the helm before I could do anything we were heading straight for the only overhanging tree on the river, she doesnt usually steer, which scraped down the whole side of the boat and took the china mans hot clean off n straight into the river. Is it only me? Anyway that was the last of that drama. Back on the pontoon and another day as I was sick of the sight of the boat by this time, I set about trying to get the water, because that is all it was, out of the bottom of the boat. I bought one of those drill bit pumps, what a waste of money. I could not get it to work for love nor money. At first I thought it was down to the fact that I was trying to pump the water too high, or maybe I had to prime it first, but no matter what I did I could not get it to work. So decided there was too much to sponge out so bit the bullet and bought a dirty water pump from screwfix. Oh it was great, once I got it primed that was, for about 30 seconds. The problem being it was only any good down to about 50mm. So, it was back to an old hand pump for the last 50mm, which was still a substantial amount followed by sponging for the last bit only to be repeated several times just incase it hadnt been just water.

 

Anyway, apologies I have been no help whatsoever but maybe it will prevent somebody from making the same mistakes, and I made them all. But I am also interested how to make it easier!

 

Oh, and for other novices like me ignore the fill marks on the side of expansion tanks as these seem to be carryover from cars. 50 litres obviously expands a lot more than 10 litres!

Edited October 21, 2016 by j04n

[bizzard]

I've mentioned it before, I think. I'd avoid using tap water in the engine cooling system and in a central heating system too, if it comes to that, especially if your local water supply is hard and develops limescale. Distilled-de-ionized water is not expensive when bought in bulk. Even filtered rain water is better than tap water, but collect it at night when its less likely to be contaminated with any traffic, aircraft exhaust or bird droppings. Avoid collecting it if the weather and rains been traveling up from due south, from hot and stinky desert climes when the rain can contain fine sand and even fishes and bits of Camel.

 

There are holes in the clouds that the rain leaks through

That's why rain is thin.

Spike Milligan.

[Neil2]

I've mentioned it before, I think. I'd avoid using tap water in the engine cooling system and in a central heating system too, if it comes to that, especially if your local water supply is hard and develops limescale. Distilled-de-ionized water is not expensive when bought in bulk. Even filtered rain water is better than tap water, but collect it at night when its less likely to be contaminated with any traffic, aircraft exhaust or bird droppings. Avoid collecting it if the weather and rains been traveling up from due south, from hot and stinky desert climes when the rain can contain fine sand and even fishes and bits of Camel.

 

There are holes in the clouds that the rain leaks through

That's why rain is thin.

Spike Milligan.

You missed a bit out...

 

There are holes in the sky where the rain gets in

 

But the holes are small

 

That's why rain is thin

 

 

It's the only poem I know.

[bizzard]

You missed a bit out...

 

There are holes in the sky where the rain gets in

 

But the holes are small

 

That's why rain is thin

 

 

It's the only poem I know.

Yes, that's it, thanks.

[Neil2]

Those of you who have done this job - what do you/did you do with the old coolant?

[Guest]

I usually take it to the local tip/recycling centre in containers and put it in the non recyclable skip. Man at tip says this is ok.

Thanks for answers and anecdotes! Gave me a smile. Think I will be fitting a tap in the lower hose at next drain down. Should be able to attach a pump direct.

Edited October 21, 2016 by Guest

[j04n]

I usually take it to the local tip/recycling centre in containers and put it in the non recyclable skip. Man at tip says this is ok.

Thanks for answers and anecdotes! Gave me a smile. Think I will be fitting a tap in the lower hose at next drain down. Should be able to attach a pump direct.

Good idea! I'll definitely be pumping it out one way or another. Dropping it in the boats too messy....... Lets see what technical advances are made in the next 4 years!

[Chewbacka]

Those of you who have done this job - what do you/did you do with the old coolant?

I rang up the Environment agency and she said 'please don't take it to the local tip as they don't always know if it requires special disposal and dump it down the drain". I asked the local boatyard and he says does not do engine servicing, but if there has been a spillage of coolant into the bilge (for example a burst hose) it is dumped into the canal. Eventually I found a local garage that would dispose of it for me for a small fee. Strictly speaking that is not allowed as he is not a licensed waste disposer but as I am confident that he does use a responsible waste disposal company I felt it a pragmatic solution to my problem.

[j04n]

I rang up the Environment agency and she said 'please don't take it to the local tip as they don't always know if it requires special disposal and dump it down the drain". I asked the local boatyard and he says does not do engine servicing, but if there has been a spillage of coolant into the bilge (for example a burst hose) it is dumped into the canal. Eventually I found a local garage that would dispose of it for me for a small fee. Strictly speaking that is not allowed as he is not a licensed waste disposer but as I am confident that he does use a responsible waste disposal company I felt it a pragmatic solution to my problem.

may the force be with you! ???

[Sea Dog]

I rang up the Environment agency and she said 'please don't take it to the local tip as they don't always know if it requires special disposal and dump it down the drain".

What!? Then the EA should be addressing their concerns with the council, not advising you not to use them. I would say that, 9 times out of 10, such advice would result in the mix going straight down the drain, so we'll done you for persevering!

 

Mine's going to the tip as it always does. I'm pretty sure both the one at home and the one close to the boat are not cowboy outfits.

[Tony Brooks]

I came late to this.

 

Don't take the lower hose off the skin tank if its difficult to get at. Take the other end off the engine and lay it in the bilge. It amounts to the same thing but is easier.

 

A wet & dry vacuum will also clean it out of the bilge plus and other bits and pieces that have got down there.

 

Unlike central heating systems it is not necessary to mix the antifreeze and water (of whatever type) before putting it in the engine. I do it pint and pint about starting with water and when its full you have the maximum of more or less 50% mixture. After several hours engine running it will be fully mixed, especially if you have a calorifier.

[Scholar Gypsy]

With my boat, I couldn't easily get the bottom hose off the pipes leading to the skin tank, so I took the top hose off. Used a Pela to pump out the old coolant, and then used a piece of spare pipe and a funnel to refill. The two pipes are adjacent to each other anyway. 27 litres capacity.

 

A few photos here: https://nbsg.wordpress.com/2016/01/24/january-maintenance-trip/

[Sea Dog]

I came late to this.

 

Don't take the lower hose off the skin tank if its difficult to get at. Take the other end off the engine and lay it in the bilge. It amounts to the same thing but is easier.

 

 

Quoted to give a second chance for this pearl of wisdom from Tony to be shared.

 

(If you end up with a weeping joint after putting it back, it's likely to be a lot easier to fix there too).

[blackrose]

I drain what I can from the engine and then use a wet vac to pull the rest out from a hose fitting at the top of the skin tank. Mine is a 2kW vet vac so there's very little left in the bottom of the tank after that, but there's always going to be some that escapes onto the floor. I just hoover it up.

[Canalwatcher]

I use Tony's method except instead of laying the hose down I keep it high and extract the 26 litres or so using a Pela suction pump transferring th used antifreeze into 5 litre containers

 

Ml

[Sea Dog]

I use Tony's method except instead of laying the hose down I keep it high and extract the 26 litres or so using a Pela suction pump transferring th used antifreeze into 5 litre containers

Ml

Works for me too. Anything that keeps my bilge dry and avoids having to disturb that hard to reach bottom skin tank connection gets my vote!

[Guest]

I do like the idea of unfasten ing at the engine end. Cheers.