1979 1/2 Merc Mariner 115 T of P water in lower unit.

[Randyme]

Hi all. I have this 79 1/2 115 Mariner T of P I bought last year attached to a 77 Sylvan I am just about done restoring. I decided to finally take a look at the gear oil and change it out yesterday and about a quarter cup of water came out with the oil. I checked the prop shaft with pressure and soapy water and it looked fine. It even held pressure without leaking so what`s going on does anybody have any ideas? Why would it hold pressure so well if it was leaking somewhere? I don`t really want to tackle this job of resealing everything myself as I don`t have all the tools and don`t have any idea how much a mechanic would charge for a reseal job. Anybody got any suggestions on which way I should go with this? I talked to the previous owner who told me it has never leaked before and also told me he just had the pump and impeller done the summer before me buying it. Your feedback would be great. Thank You all on this valuable forum.

 

[Laddies]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

Probably a water pump seal or o ring thats leaking on the w/pump base plate.

 

[Randyme]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

Thank You Laddies. I suspect your right since that was the last thing done on it and it never leaked before. Looks like a job I may be able to take care of myself too. Thanks.

 

[Texasmark]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

Thank You Laddies. I suspect your right since that was the last thing done on it and it never leaked before. Looks like a job I may be able to take care of myself too. Thanks.

I realize that you were doing a restoration, but that's why I am hesitant to "fool" with my stuff any more. I learned over the years that "if it ain't broke don't fix it" and any time you go into something your stand the chance of messing up something that wasn't messed up before you went into it. Sometimes being lazy is a virtue and the older I get the more virtuous I get. Grin.

Mark

 

[Randyme]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

Mark. I see your point but I also hate to put all this cash into it and then not have the engine be the best that it can be. I wouldn`t be too concerned if it were just a small tiny amount of water but after 2 days in a glass mayo jar it looks to be about an eight cup so I think it warrants looking into. I bought the reseal kit on Epay and what I think I`ll do is just look for the culprit seal which I think the water pump would be the first place to start since that was the last repair made on the outboard. Hopefully it`ll look obvious or if not I`ll change them out anyway, do the other easier seals and replace the impellar and leave the more difficult stuff alone for now, refill the lower unit and cross my fingers. Thanks for the reply.

 

[Texasmark]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

I have a parts breakdown for a newer engine but not that old. Maybe Laddies can walk you thru the parts that are supposed to be below the water pump on the drive shaft.

Mark

 

[Randyme]

Re: 1979 1/2 Merc Mariner 115 T of P water in lower unit.

Thanks Mark. I paid the $9.99 and bought the online manual through tradebit so I`m good on that. It`s not bad. The pictures are blurry but you can kinda see them ok. Thanks anyway.