1976 20hp. lu still leaking after installation

[jethro66]

I don't understand?I installed everyting correctlly and it leaks worse then before.When I took off the drive shaft seal it had a spring inside the seal and the one inside the kit did not. Is this the cause or am I forgetting something?

 

[samo_ott]

Re: 1976 20hp. lu still leaking after installation

Where does it leak from? Have you done a pressure test on it?

 

[F_R]

Re: 1976 20hp. lu still leaking after installation

Old seals had springs, New ones might not, especially if it is not OEM (think cheap)

 

[wbeaton]

Re: 1976 20hp. lu still leaking after installation

Like samo asked, where is the leak?

If the spaghetti seal is too short it will leak. You need about 1/16" - 1/32" over hang on the edges. I'm not sure of the exact number the manual calls for.

 

[jethro66]

Re: 1976 20hp. lu still leaking after installation

It leaks on that seal.Did not do a pressure test.Can you do this your self?The kit is not OEM (SE).Maybe It leaks underneath the water pump.

 

[HighTrim]

Re: 1976 20hp. lu still leaking after installation

To pressure/vacuum test a lower unit:

a) drain the gear oil
b) use an appropriate adapter with a gauge tee'd in to apply pressure or vacuum. No more than 15 psig for pressure. You can use a bicycle pump or any other compressed air source for pressure. For vacuum, you need a vacuum pump.
c) LU should retain some pressure or vacuum for 45 minutes minimum.
d) If pressure doesn't hold, submerge LU in water to find leak source or spray with soapy water [possibilities: drive shaft seal, prop shaft seal(s) (usually two), shift shaft seal and the fill/drain screw washers.]
e) replace offending seal(s) as required.

 

[jethro66]

Re: 1976 20hp. lu still leaking after installation

Thank you sir

 

[itstippy]

Re: 1976 20hp. lu still leaking after installation

You can whittle down an old valve stem enough to screw it into the oil fill hole, making its own threads as you turn it in. Use that to pressurize the lower unit with a bicycle pump for a leak test. As Hightrim says, 15lbs max. More and you risk blowing the good seals. Any tire shop will give you an old valve stem, they replace dozens every day.

I don't think OMC made a 20HP in 1976? What model # is your motor and what SE kit did you buy? I did a 1967 20HP a couple years ago with a SE kit. The SE kit came with two thinner drive shaft seals to replace the OEM thicker seal with the spring in it. The OEM seal had two lips. The thinner SE seals had one lip each. You stack the two thinner SE seals like poker chips. The lips inside the single SE seals face one way. When you stack them you want the lower seal's lip to face down to keep oil in the gearcase, and the upper seal's lip to face up to keep water out of the gearcase. If you point them both the same way (both up or both down) you won't get a good seal.

 

[jethro66]

Re: 1976 20hp. lu still leaking after installation

You can whittle down an old valve stem enough to screw it into the oil fill hole, making its own threads as you turn it in. Use that to pressurize the lower unit with a bicycle pump for a leak test. As Hightrim says, 15lbs max. More and you risk blowing the good seals. Any tire shop will give you an old valve stem, they replace dozens every day.

I don't think OMC made a 20HP in 1976? What model # is your motor and what SE kit did you buy? I did a 1967 20HP a couple years ago with a SE kit. The SE kit came with two thinner drive shaft seals to replace the OEM thicker seal with the spring in it. The OEM seal had two lips. The thinner SE seals had one lip each. You stack the two thinner SE seals like poker chips. The lips inside the single SE seals face one way. When you stack them you want the lower seal's lip to face down to keep oil in the gearcase, and the upper seal's lip to face up to keep water out of the gearcase. If you point them both the same way (both up or both down) you won't get a good seal.

Thank-you for your reply tippy. Sorry I took so longI will try the old valve stem method.The model # is 206B268 C56743, the coils are beside the engine block, not under the fly wheel. Everything else looks the same as my old 1972 25hp.evinrude.The SE kit is for a 18 20 25 johnson ,evinrude outboard. The motor was made in peterbourgh ontario canada I will post o photo later on. Merry xmas!!

 

[cc67]

Re: 1976 20hp. lu still leaking after installation

Then again if your shafts are grooved and the bushings worn, you won't get it to seal either.

 

[jbjennings]

Re: 1976 20hp. lu still leaking after installation

That old valve stem trick is ingenious---had to say thanks! I can also just turn the regulator down on my compressor and it won't put but about 10 or 15 lbs. in it right?
CC67 is right, does your drive shaft and prop shaft have grooves worn in them where the old seal rides? You really have to check it and get everything just right or she'll leak. I've had to redo mine 2 or 3 times to really get it right. The pressure check is key to a good job or you'll be banging your head like me and fixing things that are already right.
Good luck,
JBJ

 

[HighTrim]

Re: 1976 20hp. lu still leaking after installation

You could always use something like this.



Or use the attachmet from the lower unit oil fill pump. They screw in perfectly.