Raw water pump housing O ring

[Ziffius]

I wanted the injectors checked/serviced on my MD2030D whilst I was stuck in UK and boat in Gouvia so sent key to Reccomended Greek engineer who kept putting off the work until the day before I finally made it to Corfu. He didn’t touch them but said the SWpump was leaking etc so replaced both lip seals and engine oil and fuel filters which I had already replaced before leaving the boat.
Found the engine bay full of oil when I got to Paxos - oil was leaking from the bottom of the raw water pump where it is mated to the engine abd on closer examination could see what looks like the large o ring protruding plus one of the bottom bolts wasn’t tightened.

Anyone know the size of the big o ring that seals the housing of the raw water pump to the engine and will the engine crank case oil pour out of there if I remove the raw water pump??? I am not sure if I will be able to get the o ring on paxos but have a spares box of o rings.
 
Also is the O ring the same for both types of raw water pump? Mine is the Johnston pump that has the odd shaped impeller gasket.

[Ziffius]

The O ring number 2 in diagram but this is the other type of pump

[Markus]

What a shoddy job!

I think you will only know for sure what's wrong after removing the water pump. Perhaps you can still use the o-ring or at least you can compare the size easily against your stock or try to get a new one. So I would just take the pump out and inspect and go from there.

Not knowing where the pump is in MD2030, I am sure it's not lower than the sump where the vast majority of oil is, so you should not get a significant amount of oil pouring out when the engine is not running...

Good luck!

[Lazy Pelican]

We have a D2-40 and the oil ring for the raw water pump sits in a groove- I found it almost impossible to keep it In place while fiddling around to refit the pump. The end result was similar to yours! In the end I used an o-ring fairly tight around a ‘protrusion’ in the casting that mated on the engine casting. I first did this in 2010 and several changes of pump later no leaks.
Removing the pump you’ll only get minimal oil seeping out. Worth taking it off and having a good look- it’s not nearly as difficult as you might think.

John

[Ziffius]

Thanks John that’s great info, I thought it looks like a straightforward job to remove as it looks like it has captive nuts at the back of all 4 bolts. Will give it a go later.

[Ziffius]

That was very easy to take out going to trim the squashed out part of o ring and reuse as none of mine fit - whilst I comb paxos for one the right size

[Ziffius]

Scratch that idea the o ring has been stretched so now too big to stand a chance to fit - bet the guy that messed it up re used the old one

[Lazy Pelican]

If you find an o ring that fit reasonably snuggly around the protruding ‘brass look’ rim on the pump casting that works.

[Ziffius]

After saying to wife about hiring scooter to trawl Paxos for an o ring she wasn’t happy being on boat with no power in case someone snagged our anchor I had brainwave- try the o ring in the engine recess and it worked - and stayed there with a bit of impeller lube. Seems to be keeping oil in for now which will give me chance to find a spare!!!

[Rampage]

The O rings are 3mm thick no 68mm diameter. I used nitrile ones. You should find that CYS in Lefkas have a stock of them when you get there (assuming you’re heading that way!).
I pulled the same trick as your “mechanic” but made too much of a mess of the ring to reuse it. Instead I traced the outline of the mounting plate and cut out 4 or 5 thicknesses of card to make a gasket: used gasket goo to stick them together and that held for the rest of season until I could source a new o ring.
Note that the new o ring is not a brilliant fit round the body of the pump, hence it’s liable to get nipped. Your trick of using silicone to “stick” in place is a good tip.

[Ziffius]

Thanks Rampage, knowing correct size will help on my hunt round the island, the Gaios chandlery will probably have the right size but when I spoke to them on phone earlier I got a Curt “we don’t do Volvo penta” response!! Will see if I can find a mechanics workshop but in meantime will order spare for my son to bring out next week

[elias]

Hi , I ll be in Lefkas tonight , tell me if I can do something to help you . Every second day there is a Ferry from Lefkas to Paxos

[Ziffius]

Hi , I ll be in Lefkas tonight , tell me if I can do something to help you . Every second day there is a Ferry from Lefkas to Paxos

Thanks, off to Gaios tomorrow to hunt for one, if no luck a friend will bring one from Gouvia at the beginning of next week.