Tips for accessing V8 block drains, 240SD MPI

I mean pros drain the blue plugs but NOT the engine block lines or plugs.

I pulled the 2 drain plugs on the sea water pump (bravo).

I have not actually seen a fuel cooler but according to the water diagram I’ve seen, the fuel cooler would drain through a big hose down to the water distribution housing drain.
 
RaceCarRich said:
I mean pros drain the blue plugs but NOT the engine block lines or plugs.
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Many pros still pull the block lines and/or plugs. I can only speak from my personal experience and other guys that I know that do this for a living, though.

Another thing you can do to drain the block is just unclip the fittings at the block.

When you drained the raw water pump, a lot of water should have come out. Once it stopped, it's always a good idea to bump the engine over a few times to evacuate it all.

Which fuel cooler do you have? Or, where is it located? If it's by the port motor mount, yes.

You backfilled AF through the intake hose? You may have a check valve after the power steering cooler - which will be hard to get to.
 
I spoke to my marina mechanic and also the mechanic at a local Mercruiser dealer that’s been around over 50 years. Both thought opening the block drains was unnecessary which is why I question if we are being over-zealous.

I didn’t fill though sea water intake hose. I filled through the 3 hoses on stat housing. I’ll follow fuel line tomorrow to see if I see a fuel cooler. Even if I do, wouldn’t both it and the steering cooler drain down, through large enough hoses, to the water distribution and sea pump drains? Isn’t that the point of the 3-point drain system?

Thanks
 
Years in business isn't always indicative of the "right" answer. But just for giggles, the place I work at is coming up on 85 years. NO, you are NOT being over-zealous. Besides, you answered your own question when you found that the hoses were clogged. If you had assumed that the block fully drained, then put AF in... you would only have some "mix" of water and AF.

The "quick drain" system is a nice thought, but it's flawed - for the reasons mentioned earlier in other responses.

You are correct that, in theory, the cooler and the raw water pump should fully drain (if you bump the engine over). But the raw water pump, especially, is down low. Also, sometimes those raw water pump hoses lay somewhat flat or even have a slight dip in them. If ALL of the water isn't evacuated, guess where any remaining water that drips through the system will end up? ;)

I'm not saying you WILL have an issue - just that you can't 100% guarantee it. Fully draining and backfilling all parts does, though. The statement "we've done it this way for a long time with no issues" doesn't mean there will never be an issue.
 
LD,
Is the place you work at a boat repair place? If so, what state and do they always drain the block? Just curious for my informal survey..lol.

My driveway is on a decent hill, transom down. When I added antifreeze I lowered the trailer tongue to touch the ground and jacked the back up to get within 3 degrees of trailer level. For the winter, I’ll put the bow up again which should help with anything left in the sea water pump inlet. The outlet should be good as I witnessed antifreeze come out the plug hole before replugging.

As far as bumping the motor, are you saying the risk is water trapped between impeller blades? Are the tolerances water tight? Never heard of bumping the motor but not a big deal using my jump box (batteries out thinking I was done).
 
Yes - in fact, the seocnd oldest Sea Ray dealership in the world. We're in eastern PA and we get plenty of hard freezes during the Winter. It's not uncommon for us to be replacing someone's block, cooler or pump housing in the Spring because of not fully draining things. I also do winterizing on the side. I will only do it in a way that guarantees I don't have to buy someone a new engine! :)

Yes, the tolerances in the Bravo pump is very tight. It will sometimes only allow water to, literally, drip past the impeller. Flip the kill switch to 'off' so you don't accidentally start the engine.
 
That explains your knowledge base. Far northeastern NJ here.

I planned on switching kill switch off. Thanks for mentioning.

The fuel cooler doesn’t have a drain plug, correct?

They should have put quick connects at the manifold under the balancer were you can get to them and not on the block side! I almost installed high pressure hydraulic brass quick disconnects that I had until I noticed the ball bearings on the female side were magnetic and subject to rust. Maybe next year I’ll find some plastic quick connects for 3/8” hose.
 
RaceCarRich said:
That explains your knowledge base. Far northeastern NJ here.

I planned on switching kill switch off. Thanks for mentioning.

The fuel cooler doesn’t have a drain plug, correct?

They should have put quick connects at the manifold under the balancer were you can get to them and not on the block side! I almost installed high pressure hydraulic brass quick disconnects that I had until I noticed the ball bearings on the female side were magnetic and subject to rust. Maybe next year I’ll find some plastic quick connects for 3/8” hose.
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The cool fuel 3 module (which your 2006 should have) has a Blue drain plug.

It’s on the starboard side down low and facing forward. Pretty much right below the alternator.
 
Mine is a 2005.

Are we talking about the fuel pump module near the sea water pump that I just changed the 2 filters in? I didn’t see a drain plug. Does being an ‘05 make a difference?

So there is no separate fuel cooler on port side under manifold?
 
Cool fuel 2 would be on the port side.

Cool fuel 3 is on the starboard side. If you just changed the fuel filters in the module near the sea water pump, that’s the cool fuel 3 version.

It should have a single drain plug On it somewhere
 
I wasn't sure which cooler you had in '05 - but, yes, if it's by the pump that's the only cooler. With that cooler, you DEFINITELY want to make sure it is drained and see pink coming out - there's very small passages inside that cooler. If the boat has been in salt, it's a crapshoot. Espos4... correct me if I'm mis-remembering... didn't early versions of that fuel cooler not have plugs - instead, you have to remove the center bolt that holds the two, raw water cooling lines in place and back out the fitting enough to drain. It's best if you DO NOT remove completely. Be gentle - this style was prone to breaking.

Check out Colder Products for the quick disconnects. Good stuff - same stuff that's used on the block side. You could even use an Attwood fuel line sprayless quick disconnect (google it). Or... eliminate the block drain hoses all together and use the blue, plastic, Merc wingnuts - or whatever works for you. They're easy enough to find and remove just by feel.
 
Lazy Daze said:
I wasn't sure which cooler you had in '05 - but, yes, if it's by the pump that's the only cooler. With that cooler, you DEFINITELY want to make sure it is drained and see pink coming out - there's very small passages inside that cooler. If the boat has been in salt, it's a crapshoot. Espos4... correct me if I'm mis-remembering... didn't early versions of that fuel cooler not have plugs - instead, you have to remove the center bolt that holds the two, raw water cooling lines in place and back out the fitting enough to drain. It's best if you DO NOT remove completely. Be gentle - this style was prone to breaking.

Check out Colder Products for the quick disconnects. Good stuff - same stuff that's used on the block side. You could even use an Attwood fuel line sprayless quick disconnect (google it). Or... eliminate the block drain hoses all together and use the blue, plastic, Merc wingnuts - or whatever works for you. They're easy enough to find and remove just by feel.
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That may explain the missing drain plug.
My 2007 has one as it was replaced in 2016.
 
I googled some images. So the fittings seal with an O-ring type seal and you just loosen the retaining bolt and wiggle out a little until it leaks?

I was unable to find a pic with a drain plug but still looking.

Looks like these hoses lead down to the sea water pump and its drain. Are they also small enough to clog? In the pics they look decently large enough to not clog.
 
So looks like if it had a drain plug it would underneath at bottom, right?

Damn... why does water have to be the only room temp liquid that expands when frozen?!?!
 
The only 'clogs' that gets to these lines are salt - and age gets to the actual fittings. Yes, wiggle wiggle tell it leaks.
 
On the list for tomorrow.

So to summarize my new understanding, the 3-point drain system works fine EXCEPT for the 2-small block drain hoses and the fuel cooler lines. Everything else has large enough lines to not clog. Yes?
 
Okay.

Used the jump box to bump motor. Surprisingly it turned very slow like a dead battery using my lithium jump box reading 100%. Read 96% after. We had slightly freezing temps overnight. Hopefully it was just cold oil and parts and not trying to turn ice even though I had antifreezes everything previously.

Next I loosened the cool fuel cooler line retainer (confirmed no drain plug). What came out was pink so I quickly tightened so as to not loose all the antifreeze. Hard to see but appears that an O ring is half sticking out. Guess it’ll leak in spring and I’ll fix then rather than loosing all the antifreeze now. Any thoughts on that will be an easy job? Are o-rings o gaskets available separately?
 
That's one of the problem areas that Merc resolved later on. The aluminum housing corrodes where that O-ring seats.
 
I don't "think" those o-rings are available separately. Nor are the white, plastic fittings. I think you'd have to get the whole hose bib assembly. BUT... if it's just the o-ring that you want to replace... take it to NAPA to match up. EDIT: Those o-rings are flat o-rings, aren't they? That may make it harder to find - but maybe Google can help. Maybe round o-rings (maybe use three instead of two of the flat ones) would work, as well?

I tell 'ya what... I'd be awful tempted to tap the front side of the housing for a blue drain plug and never have to remove that bib assembly again (and seal that o-ring area up). I'm almost positive that the second gen of that housing remained the same and that's all Merc did. I may have an old one sitting on a shelf somewhere at home - I'll try to remember to take a look at it.

When you bumped the engine... did you have the pump's output hose off? Without that, it's worthless to bump the engine. With that hose slipped off (granted that sounds easier than it sometime is), you could also double check the output hose is completely clear by seeing pink come out when you backfill - whether at the t-stat or even at the power steering cooler (hard to get to in your boat).
 
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Oh... and another thing I'd probably do if slipping the pump's output hose off was a chore... cut the hose and install a drain fitting T (accepts a blue plug). That way you at least only have to unscrew the blue plug by feel - much easier. You'd only need this in the output hose.
 
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