87 merc 470 question

[blueagletalon]

i went to winterize my boat and noticed that when i pull the back plug on my heat exchanger i got anitfreeze out. is there supost to be anitfreeze in there?
plus can some one help me figure this out simpler than the book tells me to

 

[Don S]

Re: 87 merc 470 question

Yes, there is antifreeze in the manifold. The only things you have to drain on a 470 is the riser and the raw water side of the heat exchanger. But, be sure the antifreeze is really antifreeze and not mostly water.

 

[blueagletalon]

Re: 87 merc 470 question

ok i just went out and pulled the plug. it seems to be pure anti-freeze. so is it ok to pull the end off the heat exchanger off? how do i get the water out of the riser?

 

[stonyloam]

Re: 87 merc 470 question

i went to winterize my boat and noticed that when i pull the back plug on my heat exchanger i got anitfreeze out. is there supost to be anitfreeze in there?
plus can some one help me figure this out simpler than the book tells me to

No! You should get seawater from the aft plug. Are you sure that you pulled the right plug? There are two drain plugs next to each other on the underside of the (long round) heat exchanger. The seawater is the aft plug. The forward plug is antifreeze. If you have not been losing antifreeze over the summer I suspect that you did not pull the right plug.

 

[stonyloam]

Re: 87 merc 470 question

ok i just went out and pulled the plug. it seems to be pure anti-freeze. so is it ok to pull the end off the heat exchanger off? how do i get the water out of the riser?

According to the book, you can, but all you have to do is remove the aft drain plug on the exchanger, and make sure that the power steering cooler drains, you can remove the hose if need be. The riser drains through the exchanger.

 

[stonyloam]

Re: 87 merc 470 question

This is your exchanger and PS cooler:http://www.mercruiserparts.com/Show...25.png&inbr=908&bnbr=120&bdesc=HEAT+EXCHANGER the drain plugs are underneath on the right side of the drawing, those two little bumps. To drain the PS cooler just look for a drain plug underneath or pull the hose off.
It might help to trace out the seawater flow: It flows from the impeller, through the hose from the transom through the water cooled voltage regulator bolted to the side of the engine, into the front of the exchanger, through the exchanger out through the aft exchanger hose up into the p/s cooler (if you have one) up to the exhaust riser and out. Pulling the seawater exchanger plug drains everything, you only have to check to make sure that the p/s cooler drains. Good luck.

 

[blueagletalon]

Re: 87 merc 470 question

ok i must have had the wrong plug. will give her a try after work

 

[Eric 3.7LX Alpha 1]

Re: 87 merc 470 question

have a look at the attached photos which are out of Mercruiser Manual #8. Shows the exchanger and plugs on it.

 

[stonyloam]

Re: 87 merc 470 question

Ah! Eric comes through again. I do not pull the end caps off of my exchanger (too much chance to screw things up) and in my opinion if your cooling system is working OK there is no real need to. It is also a good idea to check the antifreeze to make sure it is up to spec. 50% is about optimal for both freeze protection and cooling efficiency. Good luck.