Winterizing 2007 5.0 with single point drain. Learned something and have question.

[pmtom1]

First time winterizing this one, just wanted to point something out and make sure I did everything right.

Opened hand screw (1) until water ran out. Poked drain just to be sure. Then removed hoses 3,4, 5, and both 6s. Poured AF into 3 until it ran full pink out of drain. (Was watered down at first). Then closed hand screw(1) and kept filling until it stopped / started coming out of other hoses. Did the same to 4 and 5 until I saw AF coming out of (6s) at the manifolds. Then clamped them both back on. Topped off each hose as I clamped them back on.

Then for the heck of it, I opened the top manual drain on the thermostat (2) I was surprised to see clear water coming out. Squeezed the hoses to figure out which one was supplying it (I forgot which one). Unclammped that one and filled again until AF came out #2 drain. I was really surprised how much water was trapped somewhere in there. I did a lot of research on this system and nothing mentioned that.

I was unable to see if I had flow out of the manifolds and out of the drive. So I'm going back today to check. Which hose should I fill to get AF into manifolds and out drive?

Anything else I missed? Thank you!

 

[Scott Danforth]

you have to love the hyper-complex single-point-going-to-plug-and-crack-your-block-drain system.

personally, if it was my boat, I would strip out the single point drain and all the associated hoses and go back to brass plugs

 

[pmtom1]

Scott.... I gave that some thought but there is a 50/50 chance I'll be swapping in a bigger engine early spring. I'm not sure the easy of the single point system is worth the worrying. Can't one of the drain points be plugged without you being able to tell?

 

[Bt Doctur]

with the quick-crack system you cannot be certain the block drains are not plugged with rust/corrosion.I have a customer with that system and for 2 yeas running 1 block drain is always plugged up.and I have to unplug the hose from the block and probe the opening to get it to drain. As for drain plugs:
therm housing, lower circ pump hose, cool fuel unit (if FI ot TBI),
Have reverted 3 customers back to manual drain systems. You will too when the grey plastic ball unit develops a crack

 

[Bt Doctur]

 

[Bt Doctur]

Nowhere is it written in the manual as to how much water is to drain. Most v8 blocks hold 2- 2 1/2 gallons, each manifold is just over a 1/2 gallon, add about another gallon or so for the hoses and thats how much is supposed to come out the drain plug.. Any less is water trapped in the system and a crack in the springtime

 

[pmtom1]

Yea...now I'm officially worried. Is reverting back as simple as removing all the hoses and installing manual brass petcocks? I may just do it now. Fortunately, this boat has good access around the engine.

 

[Bt Doctur]

Yes ,simple. remove the block drains and install the brass fittings that accept the blue plastic plugs
cut the small hose at the manifold drain, remove the large hose and unscrew the fitting and replace with the standard fitting with the blut drain plugs. Go to the manifold in front of the motor where the 4 hoses and simply loop them

 

[Scott Danforth]

the only reason the single point drain system was developed was for consumer reports and similar ranking systems where there are negative values assigned to maintenance points.

its the same reason grease zerks are removed.

that lower hose "spider" will have both block drain hoses plugged with dirt, rocks, rust, clam shells, etc. in many of the hoses

at a minimum, pull the two lower drain hoses off the block and see what comes out.

from the manufacturers point of view, it simply needs to make it past the warranty period.

yes, removing the drain hoses and plugging with brass plugs is that simple.

 

[Lou C]

All that foolishness when what they should have done is make closed cooling standard. Then you could simply drain the raw water side or hook up a winterization tank with -100 AF.

 

[Scott Danforth]

correct, however Mercruiser also hyper-complexificated the HX cooling plumbing as well in later years.

 

[Lou C]

True, looking at the hose schematic for that is enough to make you cross eyed!

 

[QBhoy]

Drain it with single point but you need to crack open the t stat plug too or it likely won’t fully drain. Then as mentioned I take all the quick connect fittings off just to make sure too. I’ve never had any rust or crud each time because it’s been filled with AF every winter since new. But I don’t trust the single point anyway. Then fill the hoses a little until you see af draining. Put it all back together and then fill the big hose off t stat until it comes out the t stat itself. Then take the two thin hoses off and fill them until af comes out the drive (through manifolds).
jobs a good un! Should take just under 20 litres approx

 

[pmtom1]

Thanks everyone. I'll go to the boat on Sunday and pull those quick connects off the block and check them. Will report back.

 

[Bt Doctur]

Did my customers boat last night just before the rain came and as usual the port side block drain was plugged up again

Pull the block hoses and probe the fitting

 

[Rick Stephens]

I got rid of the little fittings that take the little blue plastic plugs and went straight to a solid brass plug in both block drains. Makes it a lot easier to stick a small screwdriver in and root out the sand and crud. Still have the plastic plugs on the manifolds. Don't know why, but the manifold drains never seem to get plugged up with crud. And I put a plastic T in the line next to the oil cooler so I don't have to squeeze in there and pull the hose off.

 

[QBhoy]

Did a friends 350 mpi this evening. Not a single point exactly like this, but has a common drain system. Drained using that and pulled the quick connect fittings on the block just in case. The port one was blocked. Just as well I did. His boat has never had antifreeze in it over winter, so was blocked with rust and flakes from the internals.

 

[pmtom1]

Got back there yesterday and after completing my audition for circue du soleil contusion act to get in the box, I was able to check them out. Port was good but starboard was plugged bad. Took a good amount of poking and prodding to clear it. In the end, less then a cup of water came out before the AF flowed solid but I feel much better.

So I've seen the brass T fittings everyone likes. But how do they attach? Are the current quick disconnect fittings on the block simply threaded on? So you grab it with vice grips and unscrew? What about seating the brass fittings? Anything on the threads?

thanks once again everyone for "bailing" me out!

 

[Scott Danforth]

NPT fittings seal on the "crush" of the tapered threads. for a block drain, really nothing is needed, even with brass plug threaded directly into the cast-iron (my preference). sealant is used primarily for slight imperfections in the threads and the material.

I used pipe dope for decades.