lower unit still leaking

[tgissel]

1957 Johnson 35 h.p. lower unit still leaking after new seals and pressure test, I have heard you do a vacuum test on these lower units after rebuild. But how do you test it and if it does leak how do you find the leak? Motor is RDE-19. Thank you,

 

[alcan]

Re: lower unit still leaking

Very simple, you can buy a vacuume pump kit from your auto parts or tool store. You should be able to get a dandy for about $35. Don't worry if you have one you will find plenty of uses for it. Connect it to the L/U and draw a vacuume of 15HG. There is a gauge on the pump. I use the adapter from a gear oil pump for the test. If you have a leak you will see the gauge drop, you may also hear the air sucking. If not apply a squirt of oil to the suspected area. When you resealed your gear case did you replace the shift shaft o-ring?

 

[tgissel]

Re: lower unit still leaking

Thanks Alcan, I have the vacuum pump just wondering how to tell. The oil on the suspected area helps alot. Yes I did change the shift shaft o-ring. When I tried the pressure test it held overnight. I will try the vacuum test tonite. Thanks again,

 

[BillP]

Re: lower unit still leaking

Did you change the driveshaft seal under the water pump?

 

[DHPMARINE]

Re: lower unit still leaking

tg when you installed the seals,did you apply a sealer to the outside (metal) edge of the seals ?<br />Some older manuals don't menion this.<br />DHP

 

[Evinrude Boater]

Re: lower unit still leaking

Is the leak coming out of the exhaust or prop? I just got my lower end to stop leaking on a 1964 75hp and it turns out the single oil retainer seal under the water pump has been changed to two seals installed back to back. The original seal was an O-ring type in a metal carrier ring pressed into the bearing cap. The new arrangement is two, lip type seals installed one with lips toward the gear case and one with lips towards the water pump. Fill the gap between the lips with grease prior to sliding over the drive shaft. And yes, don't forget to apply a light coat of sealer to the metal perimter of each seal before pressing into the bearing cap. I can't tell from my manual if your 35hp has a removable bearing cap under the water pump. If it does, you'll have to make sure the O-ring is installed properly and that you have gasket sealer on the bearing cap flange before you bolt it down. Good luck.

 

[tgissel]

Re: lower unit still leaking

Thanks, BillP yes I did change the driveshaft seal. DHPMarine I applied a light film of grease to the outside edge of all the press in seals. T Semenuk I looked at everything going in and coming out and all of the new seal kit looked the same. I vacuumed checked it tonight and it seems to be leaking around the bottom part of the foot where the spaghetti seal goes guess I will pull that apart and check again. Thanks again,