Rear main seal leak/boot leak boat pics added

[jonny rotten]

Looking at an 87 boat with a 4 cylinder mercruiser.The guy says it has an oil leak that he thinks is the rear main seal.Also the boot on the out drive he said he changed but still leaks.Is the rear main seal difficult to change.I know I need to pull the engine but Ive done that before.Ive never worked on the internal parts of a motor.I not a mechanic but mechanically inclined. If I can do the boot and seal I think Ill have gotten a good deal

 

[cr2k]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

If the oil was in the boot it is the front seal on the drive and fairly easy diy. If it is the rear main on the engine, it has to come out. Still diy able.

 

[Bondo]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Looking at an 87 boat with a 4 cylinder mercruiser.The guy says it has an oil leak that he thinks is the rear main seal.Also the boot on the out drive he said he changed but still leaks.Is the rear main seal difficult to change.I know I need to pull the engine but Ive done that before.Ive never worked on the internal parts of a motor.I not a mechanic but mechanically inclined. If I can do the boot and seal I think Ill have gotten a good deal

Ayuh,..... From the Info of yer story,...

If ya plan on a Full Rebuild of the motor, 'n the drive,....
Ya might come in Under budget...

In other words, there's Probably awhole lot more problems ya ain't found yet....
Plan on the Worst, 'n pray for the Best....

 

[jonny rotten]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Ayuh,..... From the Info of yer story,...

If ya plan on a Full Rebuild of the motor, 'n the drive,....
Ya might come in Under budget...

In other words, there's Probably awhole lot more problems ya ain't found yet....
Plan on the Worst, 'n pray for the Best....

curious why a seal and outdrive boot would turn into a full rebuild. If its running well with good compression,what equals rebuild?Granted its 25 years old,but has never seen saltwater

 

[achris]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

When the PO says the bellows are still leaking. Is that leaking water into the bellows or oil into the bellows? There is a world of difference for fixing the problem.

I suspect what Bond-o means is that once the engine and drive are pulled you find a whole nest of new 'unknown' problems and will have to go into the engine and drive a lot further than originally planned. So budget big... Hope for small...

Chris.....

 

[ENSIGN]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

It's a 87 boat so you have to decide(do i want to work on a boat all summer ?? At least start it up and check the compression !

 

[jonny rotten]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Ill be checking the compression before I take the ride.Owner says water is leaking into bilge from "out drive boot" No water in oil,no blow-by.Il be taking it for a test ride,a bonus this time of year.Are there any other field tests I can do?

 

[cr2k]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Raise the drive and check the bellows first. You don't want to sink on the sea trial.

 

[achris]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Ill be checking the compression before I take the ride.Owner says water is leaking into bilge from "out drive boot" No water in oil,no blow-by.Il be taking it for a test ride,a bonus this time of year.Are there any other field tests I can do?

Water leaking into the bilge through the bellows also means good-night to the unis and gimbal bearing (at the very least)....

If the water that's been leaking in is sea (salt) then find another boat. That salt water will have been having a party at the expense of the aluminium gimbal housing where the bellows secures to it.... Once that starts to corrode it's all over bar the crying... New gimbal housing time...

Chris........

 

[jonny rotten]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

Water leaking into the bilge through the bellows also means good-night to the unis and gimbal bearing (at the very least)....

If the water that's been leaking in is sea (salt) then find another boat. That salt water will have been having a party at the expense of the aluminium gimbal housing where the bellows secures to it.... Once that starts to corrode it's all over bar the crying... New gimbal housing time...

Chris........

Its been in fresh water its entire life,and still is.The leak is small,bilge kicks on once and a while

But again,any other field test I can do?

 

[dubs283]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

The leak is small,bilge kicks on once and a while

doesn't matter if the leak is big or small, the damage is done - as stated a new gimble bearing and possibly u-joints for sure, after that cross your fingers

But again,any other field test I can do?

pull the drive, drain lube and pressure test, while the drive is off, a thorough inspection of the transom assy is a must

 

[jonny rotten]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

It seems as if the general consensus is "Dont buy".But then how does anyone buy an older boat?At $1,800 for a good running 19ft bowrider,with perfect interior thats never seen salt,I think Im willing to take the chance.At that price Ill have money for repairs

 

[Bondo]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

View attachment 128245View attachment 128246View attachment 128247It seems as if the general consensus is "Dont buy".But then how does anyone buy an older boat?At $1,800 for a good running 19ft bowrider,with perfect interior thats never seen salt,I think Im willing to take the chance.At that price Ill have money for repairs

Ayuh,....If you don't turn yer own wrenches,...
That number could easily double, or triple.....

Probably needs a complete replacement of all the rubber parts at the transom, at the very Least...

 

[fishrdan]

Re: Rear main seal leak/boot leak

Re: Rear main seal leak/boot leak

It seems as if the general consensus is "Dont buy".

It's not, "Don't Buy", it's just that there could be a lot more problems discovered after digging into it further. You could come out lucky and fix the problems yourself with a transom seal kit, gimble bearing, Ujoints and an engine seal kit,,, probably $300-500 for everything needed and a couple days of work.

OR,,, (since the PO said the bellows were changed and it still leaks),,, the transom might be shot, leaking in around the gimble housing, which would require major work rebuilding the transom. Plus, all that corroded aluminum on the gimble ring, gimble housing and trim rams doesn't give me a warm fuzzy feeling inside...

It might run fine on a sea trial, but still have major problems. It's hard to tell what problems the boat has without further inspection.