Pressure testing drive

I know I have seen this here before, but can't find it right now. How can I make a pressure tester for my drive? I am thinking of using the hose off of an old oil fill pump and a bicycle pump for the air supply. What is a good guage to use to monitor pressure? <br />Am losing oil somewhere, but no sign of oil drops on the ground. I'm thinking prop seal.<br />Also I found water in my drive. About 2 cups drained out of the bottom when I pulled the fill plug. This is not a surprise since this was a used drive that had been sitting for many years outside with no oil. Where would the most likely place be to look for the water intrusion into the lower drive unit? Would the bellows allow water in this part of the drive?<br />Almost forgot, it is a mercruiser older style drive, R I think is what it is called. The kind with the loop on the top cover. 165HP mercury inline 6.

Re: Pressure testing drive

it can get in lower from the prop shaft or whey ever is below the water pump and the shift shaft<br /><br />the upper has the seal in the bellows area and ones were the shaft enters from the lower<br /><br />you need to use vacume also and spin the drive when your testing sometimes they only leak when you turn it<br /><br />i can take a picture later if nobody posts one <br /><br /><br />tommays

Re: Pressure testing drive

I never thought of the shift shaft. It was not showing any signs of water in the drive oil until I took the lower off and replaced the impeller, the next trip out it had about 2 cups of water in the oil and the oil is milky. When I put the drive back on I messed up and got the shift coupling ina bind when I tightened everything back down. I probably wrecked that seal when I did this. <br />The prop shaft is showing a slight drip down the skeg too.

Re: Pressure testing drive

if you opened the drive you did not get the quad ring in between the upper and lower correctly<br /><br /> <br /><br /><br />tiny black ring on penny<br /><br /><br />tommays

Re: Pressure testing drive

That is probably the deal. So where does this ring go to be in correctly? I don't remember seeing anything looking like that, and a friend has my manuel right now.

Re: Pressure testing drive

Hope this helps DD <br /><br /><br />

Re: Pressure testing drive

Look around the mating surfaces between the upper and lower gearcase. The oring mates between the upper and lower.

Re: Pressure testing drive

Thanks everyone for the info. I will split the drive again and check it out.

Re: Pressure testing drive

Well, I pulled my drive back apart, and feel like a complete idiot. As I was clearing my work bench I found a greese rag I use all folded in a neat little square. Inside of this I found am o-ring and a square o-ring. Somehow I forgot to put both of these on the shaft when I installed the lower drive unit. My book says that if this o-ring is bad or the shaft is corroded it will allow water in the drive. Hopefully this will solve the problem. <br />The quad ring looked good and was in place.<br />As always, thanks for the help.