1979 Mercruiser 470.
Yesterday I noticed an antifreeze leak (big surprise, huh). I traced it to a small hole in the water pump. The hole is about 7 o'clock or so viewed from the front of the motor. I am assuming that it is a weep hole just like an automotive water pump. New water pump soon.
I had never seen an antifreeze leak on the motor before, and knowing a little about the cam seal problems on these motors, it freaked me out a little.
While I was looking for the source of the leak I remembered reading about a drip passage in the front of the engine that would indicate a seal failure on one of the cam seals. The previous owner had allegedly replaced the seals, and from the amount of RTV on the cover I can see that it has been off.
I couldn't find a drip passage at the bottom of the timing cover, but I did find a brass plug that is almost directly under the water pump.
Reason tels me that this is NOT the drip passage, and is in fact a coolant drain for the closed system, but the pessimist in me believes it possible that the PO plugged this passage with a brass plug to ensure that no antifreeze would leak out if the seal failed.
My question is, where is the drip passage that would indicate that the cam seal had failed? And is the brass plug indeed a coolant drain?
(I loaned my manual to a friend at work who tore up his drive a couple of weeks ago, so I can't just look there.)
Sterndrives.com shows a picture of the 470 timing cover and the drip passage is labeled, but this is where the plug was, and later in the repair procedure it says to drain the cooling system through a brass plug in the bottom of the timing cover. (link: http://www.sterndrives.com/35.gif )
Any help appreciated.
Yesterday I noticed an antifreeze leak (big surprise, huh). I traced it to a small hole in the water pump. The hole is about 7 o'clock or so viewed from the front of the motor. I am assuming that it is a weep hole just like an automotive water pump. New water pump soon.
I had never seen an antifreeze leak on the motor before, and knowing a little about the cam seal problems on these motors, it freaked me out a little.
While I was looking for the source of the leak I remembered reading about a drip passage in the front of the engine that would indicate a seal failure on one of the cam seals. The previous owner had allegedly replaced the seals, and from the amount of RTV on the cover I can see that it has been off.
I couldn't find a drip passage at the bottom of the timing cover, but I did find a brass plug that is almost directly under the water pump.
Reason tels me that this is NOT the drip passage, and is in fact a coolant drain for the closed system, but the pessimist in me believes it possible that the PO plugged this passage with a brass plug to ensure that no antifreeze would leak out if the seal failed.
My question is, where is the drip passage that would indicate that the cam seal had failed? And is the brass plug indeed a coolant drain?
(I loaned my manual to a friend at work who tore up his drive a couple of weeks ago, so I can't just look there.)
Sterndrives.com shows a picture of the 470 timing cover and the drip passage is labeled, but this is where the plug was, and later in the repair procedure it says to drain the cooling system through a brass plug in the bottom of the timing cover. (link: http://www.sterndrives.com/35.gif )
Any help appreciated.