Draining Coolant

[Old Son]

I need to drain my engine coolant. I was thinking of removing the lowest pipe on the engine/skin tank. What do you people drain this into? The skin tank connections are so low I cant get anything under the outlets to drain into.

 

How do you do it?

[Bobbybass]

My engineer...used to just let it flow into the bilge...and then hand pump it into a container...rather than try and catch it.

[Mike on the Wey]

I need to drain my engine coolant. I was thinking of removing the lowest pipe on the engine/skin tank. What do you people drain this into? The skin tank connections are so low I cant get anything under the outlets to drain into.

 

How do you do it?

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.

[Tacet]

The most difficult part to extract from the bilge is usually the last bit. So unless you are confident that you can catch almost all the old coolant, it may be easier to dump the lot in the bilge (and any flushing-out) and then pump or bail it all. A plastic dustpan can be useful for scooping out.

 

This does assume that any coolant in the bilge won't combine with something horrid or somehow cause problems during the short period it resides there.

 

 

[Tony Brooks]

It will be just as effective if you take the engine end of the lower hose off and manipulate it so the hose lays in the bilge. Usually the engine end is higher and easier to get at.

 

There should also be a block and possibly a manifold drain tap/plug. Those drain into the engine drip tray so its easier to clear out the coolant if you start with a clean drip tray.

[Guest]

Next time I do this awful job, /i have a reducing tee standing by, which will be fitted into the lowest point along with a valve. This will then have a compression fitting of some sort into which the pipe from my Pella pump or similar will fit.

There has got to be a better way than dumping the stuff into the bilges.

[Old Son]

Thanks everybody, I am really not keen to have around 50 litres of old antifreeze mix in my bilge. There must be another way!! If I can think of a 'cleaner' way of removing the antifreeze I will let you know.

 

I have some 5 gallon diesel cans. How do I clean these after I have used them to ensure I wont cause an issue when I use them for diesel again?

 

 

Presumably there is no need to ensure every drip is removed from the system? I seem to remember we had a real issue with air locks when we first filled the system. The main air lock issue was around the calorifier and that was eventually resolved by loosening joints at various places around the system.

[Sea Dog]

Thanks everybody, I am really not keen to have around 50 litres of old antifreeze mix in my bilge. There must be another way!! If I can think of a 'cleaner' way of removing the antifreeze I will let you know.

Last time I drained down the block from its drain point into gallon plastic containers, then used a cheapo plastic syphon pump, poking the suction tube down the top hose connection of the skin tank, but my skin tank connections are a sod to work on and it took me ages to get a good seal again. Next time I'll be using Tony's tip and disconnecting the lower hose at the engine end to go in through there. The syphon pump works manually when there's not enough head to start a syphon action, so I got everything out into the plastic containers, retaining a dry bilge apart from the odd dribble. The local tip were happy to accept the used coolant, which is harmful to aquatic life.

 

As for airlocks, I added a couple of vent valves at the high point of the engine/calorifier feed and return circuits (when I rerouted the hoses to cure thermosyphon issue which was cooling my tank overnight) and these worked a treat.

[Tony Brooks]

Snip

 

Presumably there is no need to ensure every drip is removed from the system? I seem to remember we had a real issue with air locks when we first filled the system. The main air lock issue was around the calorifier and that was eventually resolved by loosening joints at various places around the system.

 

 

I certainly would not even attempt to drain the calorifier circuit apart from what it may do on its own unless I was changing antifreeze types. But even then I would do it by flushing with several changes of ordinary water and running the engine rather than letting air into that circuit.

 

 

 

[cuthound]

I used Ford Super Premium 10 year antifreeze when I changed my mine, both in the engine and the central heating.

 

However it is not suitable for circuits containing copper or brass, (often found in older engines), but as my boat has a modern Japanese engine, plastic heating pipes and a stainless steel calorifier it wasn't an an issue for me.

[Old Son]

 

 

I certainly would not even attempt to drain the calorifier circuit apart from what it may do on its own unless I was changing antifreeze types. But even then I would do it by flushing with several changes of ordinary water and running the engine rather than letting air into that circuit.

 

 

 

 

How do you change the fluid without letting air into the circuit? My skin tanks, engine and calorifier are all connected by pipes of varying sizes without and shut off valves.

[dmr]

Can I just hijack this thread a little please?

 

I really can't face up to draining my coolant, its a floor mounted skin tank under the engine. I just take about 4 litres out of the engine every other year and replace it with new stuff to hopefully keep the rust inhibitors etc topped up. I fact I did this just the day before yesterday.

My question is, how do I ethically and safely dispose of this used antifreeze? The local tips take oil but not antifeeze.

 

I read somewhere to just tip it down the toilet but as we have a pump out I think that would be rather foolish.

 

............Dave

[Afloat]

taken from

 

https://www.gov.uk/how-to-classify-different-types-of-waste/vehicle-and-oily-wastes

 

 

Fuels, brake and anti-freeze fluids and diesel

 

Antifreeze containing hazardous substances Hazardous 16-01-14*

Antifreeze not containing hazardous substances Non-hazardous 16-01-15

(*) An asterisk at the end of a code means the waste is hazardous.

 

find a tip that takes it ...... https://www.gov.uk/hazardous-waste-disposal

Edited December 3, 2016 by Afloat

[Tony Brooks]

 

How do you change the fluid without letting air into the circuit? My skin tanks, engine and calorifier are all connected by pipes of varying sizes without and shut off valves.

 

 

I wrote: "I certainly would not even attempt to drain the calorifier circuit apart from what it may do on its own unless I was changing antifreeze types. But even then I would do it by flushing with several changes of ordinary water and running the engine rather than letting air into that circuit."

 

See the part in red. Some installations main drain the calorifier circuit completely while others may hardly drain any of the contents at all. If it drains on its own it is likely that when filling it will expel the air. If coolant stays in the circuit and you undo unions etc. to drain it then its unlikely to expels the air so you then have to bleed it.

[dmr]

taken from

 

https://www.gov.uk/how-to-classify-different-types-of-waste/vehicle-and-oily-wastes

 

 

Fuels, brake and anti-freeze fluids and diesel

 

Antifreeze containing hazardous substances Hazardous 16-01-14*

Antifreeze not containing hazardous substances Non-hazardous 16-01-15

(*) An asterisk at the end of a code means the waste is hazardous.

 

find a tip that takes it ...... https://www.gov.uk/hazardous-waste-disposal

 

Pretty useless link

It asks for a postcode and then just forwards to the website of the local council, not even to their "tip" section.

We are CC'ers and getting shot of bad waste can be quite tricky. We do keep a car with us in the winter but it leave it behind in the summer.

A very worrying development is that recently I was refused entry to the tip in Newbury, it is now strictly residents only and every house has been sent a tip permit. This was particularly depressing as I went just to drop off an old battery which is worth money.

If this trend spreads across the country it will be very bad news for boaters who do not have a local address.

 

..............Dave

[Old Son]

 

 

I wrote: "I certainly would not even attempt to drain the calorifier circuit apart from what it may do on its own unless I was changing antifreeze types. But even then I would do it by flushing with several changes of ordinary water and running the engine rather than letting air into that circuit."

 

See the part in red. Some installations main drain the calorifier circuit completely while others may hardly drain any of the contents at all. If it drains on its own it is likely that when filling it will expel the air. If coolant stays in the circuit and you undo unions etc. to drain it then its unlikely to expels the air so you then have to bleed it.

Thank you. I didn't completely understand how you could leave it to what it may do on its own and suggest it would not let air into the circuit. You were not actually saying that. Maybe the reason I had a massive issue with air locks was that it was filled for the first time. Perhaps I should just take off the bottom hose, let it drain, flush it through then fill with antifreeze and hope for the best.

[pearley]

Can I just hijack this thread a little please?

 

I really can't face up to draining my coolant, its a floor mounted skin tank under the engine. I just take about 4 litres out of the engine every other year and replace it with new stuff to hopefully keep the rust inhibitors etc topped up. I fact I did this just the day before yesterday.

My question is, how do I ethically and safely dispose of this used antifreeze? The local tips take oil but not antifeeze.

 

I read somewhere to just tip it down the toilet but as we have a pump out I think that would be rather foolish.

 

............Dave

We used a wet vac to drain ours.

 

Pretty useless link

It asks for a postcode and then just forwards to the website of the local council, not even to their "tip" section.

We are CC'ers and getting shot of bad waste can be quite tricky. We do keep a car with us in the winter but it leave it behind in the summer.

A very worrying development is that recently I was refused entry to the tip in Newbury, it is now strictly residents only and every house has been sent a tip permit. This was particularly depressing as I went just to drop off an old battery which is worth money.

If this trend spreads across the country it will be very bad news for boaters who do not have a local address.

 

..............Dave

Other boaters have said of being refused at various places around the country but I've not yet been. However, I always try to buy my oil from boatyards and always ask if I can get rid of the old stuff there. Often saves a long walk.

Edited December 3, 2016 by pearley

[dmr]

We used a wet vac to drain ours.

Other boaters have said of being refused at various places around the country but I've not yet been. However, I always try to buy my oil from boatyards and always ask if I can get rid of the old stuff there. Often saves a long walk.

 

I buy my oil 25l at a time from Morris but have found a few yards around the system who will still take my old stuff. One or two places will just take it but at most others I buy a load of diesel or get a pump out first and then ask which seams more reasonable to me. The tip just outside Middlewich is canalside so really useful, hope they don't start a residents only scheme.

Still not sure what to do with the antifreeze though.

Trouble is most places now have to pay to get their used oil taken away so its not really in their interest to provide a free disposal service to boaters. I think if you have a really big tank that it might just be collected for free, the value of used oil is very low so its not worth the drivers cost to collect anything but huge amounts. I expect antifreeze has even less value??

 

...............Dave

[Sea Dog]

I expect antifreeze has even less value??

 

Which is, of course, true. Once the 'public service' element is removed from the council tip however, the result is fly tipping which, in the case of antifreeze, means entering the watercourse and killing aquatic life. It's a short-sighted, penny-pinching approach for councils to make disposal difficult in my view.

[FadeToScarlet]

A way I've heard...

 

Sharpen a small copper pipe with an oblique cut on the end. Attach a valve.

 

Push through the side of the lowest rubber hose, then use the valve to drain into a container or a wet vac. Use a wet vac to suck out the dregs.

[Guest]

A way I've heard...

 

Sharpen a small copper pipe with an oblique cut on the end. Attach a valve.

 

Push through the side of the lowest rubber hose, then use the valve to drain into a container or a wet vac. Use a wet vac to suck out the dregs.

That is how kids nicked sugar etc from sacks on the back of wagons, whilst stuck at a red traffic light, when I was a kid: Jab a piece of sharpened pipe into a handy sack, and hold a bucket under the other end. Withdraw pipe and run like f*** when the driver cottoned on or the lights changed.

[Sea Dog]

That is how kids nicked sugar etc from sacks on the back of wagons, whilst stuck at a red traffic light, when I was a kid: Jab a piece of sharpened pipe into a handy sack, and hold a bucket under the other end. Withdraw pipe and run like f*** when the driver cottoned on or the lights changed.

 

You didn't need to worry about mending the hole in the sack though, eh?