The first trip in 2016, to complete a number of maintenance jobs:
- insert some drain points into the engine cooling circuit
- drain the coolant, and flush the system
- refill with new antifreeze – the red stuff from Europarts, which should last for five years
- change the fan belt
- change the oil and oil filter
- change the fuel filters.
Captions are above the photos to which they refer. More information on volumes of fluid etc is at the foot of the posting …
All the clobber on the foredeck. 45 litres of new coolant, two dustbins (capacity 80 litres each) and assorted junk.
New plumbing — circuit diagram here (and a discussion on CWDF). The lower valve is a drain, the right hand one closes off the return to the engine. The idea is that, with a clean skin tank, when running the engine cold one can flush clean water around the engine and through the calorifier.
I was pretty sure there was a venting point in the top of the skin tank, but could not find it. Eventually (after taking the bed to pieces) had to conclude there wasn’t one.
Draining the skin tank, using a Pela oil pump (bottom right, capacity 6 litres) stuck down the top pipe into the skin tank, after removing the top hose that runs from the engine to the skin tank.
Filling the skin tank, with a bit of spare hose to give me a temporary header tank (the red funnel). Then reconnected the top hose and filled the main header tank.
After this a quick spin to the south of Ely, to test all was working well, then moored stern on to get the dustbins off.
Then moored for the night at the Cutter Ferry (and next door to WILLOW).
Old coolant, and flushing water, ready for disposal.
Detailed description of flushing/draining
- remove 1L from header tank, using hand operated syphon. Five disks on the tester, top of the scale on the new refractometer (so ca -40 degC). New coolant (nominally 50:50 dilution) shows the same.
- Flushing of main skin tank. 5+ buckets of 9 litres. – 47L of water put through. First four buckets show as three disks on tester, last bucket shows nil antifreeze content.,
- Flushed engine and calorifier – 27L (3 buckets). First 9 litres had some antifreeze, next 18 had none. Estimate capacity of that part of circuit as 5 litres?
- Gravity drainage about 3L, then 24L pumped from skin tank via top hose. So expected capacity for refilling about 27L.
- Filled with 5L on concentrated antifreeze and 23L of 50:50 mixture
- Engine started and ran first time, bypass circuit operated immediately and then thermostat opened as normal.
- Topped up header tank with another 0.5L of coolant.
With the benefit of hindsight, I would do this slightly differently next time (in five years!), ie
- first drain the skin tank,
- then refill (partially, several times?) with clean water,
- then flush it around a bit, and then flush the engine and calorifier circuit,
- and then pump it all out.