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Post by MalcolmP on Oct 9, 2012 17:40:54 GMT
As we used the engine 39hp 3JH4E a lot this season I am now in the middle of a major service - I have previously changed the diesel filters ( The primary is a Delphi CAV) and the secondary Yanmar one without a real problem - other than having to pump the lift pump for maybe 10 mins to get the fuel through. But today although the primary filter bowl has filled I cant get fuel to exit the bleed screw at all. The tank is just less than half full and normally I keep that above half so wonder if that may be part of the issue?
The next question is replacing the coolant which has been done previously by engineers, looking at the manual it ambiguously refers to a drain on the front of the engine (behind the fan belt) which I can't see at all and also one at the base of the heat exchanger. The coolant of course also goes through the calorifier in the saloon which is at a slightly lower level than the engine. There is a drain cock on the calorifier (which has evidently not been used before) for the engine coolant which I can attach a hose that hopefully will get to a point above the sump - my question is if I ran the engine for a short time should I be able to pump out most of the coolant then maybe just drain the heat exchanger?
Thoughts appreciated
Malcolm
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Post by rxc on Oct 10, 2012 7:05:45 GMT
Malcolm,
I did this coolant change on my 4JH3TE 2 years ago, and I used the three (I think) drains that had petcocks with clear tubing attached to drain the coolant into empty jugs. I believe that most of it came out, and after it all stopped flowing, I refilled the system, not worrying about any bits not drained.
You are right about the dwgs being a bit "obscure". I think that you might be able to run the engine for less than 30 seconds without coolant without doing any damage, to move any remaining coolant around, but since the FW pump is a centrifugal pump, once it is empty, it will not pump anything. That is why I would not worry about the last bits of coolant.
How long has it been since you drained the coolant before? We went 8 years from the date of the boat build before first changing it, and the coolant seemed to be in quite good condition.
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Post by MalcolmP on Oct 10, 2012 10:04:03 GMT
Thanks for your reply Ralph. I thought that the coolant had been changed at an annual service, but not sure. I have not personally done this before so maybe 4+ years. There seems to be only 1 petcock on the bottom of the heat exchanger that I can see. Did you also drain the calorifier?
On the fuel filter issue I have found that Delphi CAV do a primary filter unit that has a built in priming pump, so plan to change to that, hopefully will solve that issue
will let you know how it goes
Malcolm
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Post by j on Oct 10, 2012 10:07:12 GMT
other than having to pump the lift pump for maybe 10 mins to get the fuel through. Sometimes you need to crank the engine over so that the pump cam is lined up explained here: www.yanmarhelp.com/s_bleed.htmIt wasn't for us, we only had 20 litres in the tank when I changed the filters. (3ym30 - 36i) engine block drains are usually inconspicuous bolts. One way to flush it out is to take the hose off the engine that sends coolant to the calorifier, and blow the water out (~1 litre) - refill the hose with water, blow that out and repeat until clear water comes out (have the heat exchanger drain open + block off the outlet that you took the hose off so water doesn't spurt out) if you just drain from the exchanger you'll leave old coolant in the block. If it's been a while it wouldn't be unusual to have a bit of sediment come out of the engine block drain. Make sure that you do not have an air block in the system when you refill it. |
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Post by rxc on Oct 11, 2012 1:46:20 GMT
Malcolm,
Hmmm... calorifier... hot water heater!
No, I did not drain the piping to the calorifier. Now that you say that, it would probably be a good idea. I also like the idea from J to drain and refill with fresh water to do a flush and then drain again.
Looking at the exploded parts dwgs for my engine, I think there are two drains aft, and one fwd. I remember one just above the starter, and another on the sbd side aft, but I don't remember finding the drain at the fwd end of the engine, under the water pump.
Something else to add to my todo list in November...
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Post by so40gtb on Oct 13, 2012 3:53:37 GMT
Yanmar engines have both fresh and sea water drains. And, yes, the drawings in the manuals are often "clear as mud"!
The fresh water drains have clear plastic hoses attached (well, unless removed by a diabolical prior owner), which makes them easy to identify. I drain each into a plastic cup until no more coolant comes out, sequentially, pouring the cup into a recycling bottle as needed, and repeat. Do ensure that the top fill cap is off when draining, to ease air replacement of drained coolant.
Then I move on to refill, with some short engine runs to pull the coolant into place and get the air out. Starting the engine with minimal coolant in it seems like an invitation to trouble, IMHO.
This has been the procedure on the 3GM30 in what was our SO34.2 and now the 4JH3E in our SO40.
I did not bother to drain the water heater lines in either boat. In the greater scheme of things, the amount of coolant therein is small and largely inconsequential, especially if one is diligent and replaces fresh loop coolant biennially. Besides, "the water heater is your sworn enemy" and will do all it can to try to soak you, especially with glycol coolant, so it's best to avoid removing hoses to it if at all possible!
--Karl
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Post by MalcolmP on Oct 20, 2012 10:08:49 GMT
On the fuel filter issue I have found that Delphi CAV do a primary filter unit that has a built in priming pump, so plan to change to that, hopefully will solve that issue will let you know how it goes Malcolm All sorted. The picture is the new filter with built in priming pump, saves a lot of hassle  |
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Post by electricmonk on Nov 22, 2012 14:25:40 GMT
Its only my opinion (as an engine maker) but introducing another pump into the fuel supply line could turn out to be the source of more air leaks, lets hope not.
Rotating the engine to align the cam on the lift pump is the best idea, you only have to mess about once to find the sweet spot, then mark the crankshaft pulley for future services.
In general its a good idea to change the coolant on the fresh side every once in a while BUT please ensure you use a recommended antifreeze/corrosion inhibitor and deionised water - there are/were many cases of problems in this area.
Sea water side.
IF you are draining the seawater to reduce the risk of damage from freezing then you may not succeed, IF you are draining the sea water side to reduce the rate the corrosion in the heat exchanger you may not succeed because some water may remain. The best solution is to fill the sea water side with a mixture of water and antifreeze/corrosion inhibitor that will protect the engine against any low temperatures expected and inhibit corrosion. This solution will also protect the raw water pump, back flow preventer and exhaust piping.
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Post by Mistroma on Nov 23, 2012 23:20:57 GMT
Fresh water side
I drained mine this year, refilled with water, ran and refilled again with water. Coolant was still coloured at first flush and was pretty clear second time around.
I collected the coolant and water each time and the volume was just slightly over the figure given for the capacity. So I was pretty certain that I was getting all of it apart from some of the calorifier feed. I didn't see any sediment and retained the old coolant to flush the sea water side in subsequent seasons (see note below).
I refilled with Yanmar ready mixed long life coolant and had no problems with leaks or air locks.
Sea water side
I agree with previous post about using antifreeze and that's exactly what I do at end of each season after lift-out.
Procedure is along following lines:
1) Remove the top of the water filter
2) Flush water back through the open hull inlet valve
3) Close hull inlet valve
4) Run engine & feed water into water filter
5) Adjust hose nozzle to keep water level near top of filter
6) Run until engine warm (I think around 15-20mins)
7) Pour 50% antifreeze solution into filter until it appears at exhaust
8) Pour in 0.5-1.0 litres of neat antifreeze
9) Let engine pump out all antifreeze & then stop (~1min)
10) Open hull inlet valve
Quick, easy and seems to do the trick.
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