Volvo 280 leg leak can't find?

I had a Volvo Penta 280 leg that is leaking oil in to the drive shaft bellows. After inspecting the leg oil I found it was all milky. I removed the upper and lower gear case and replaced all seals and O-rings and pressure tested it. Ran the boat a couple times and checked the oil and again water in the oil. Pulled the upper gear case and had water in the bellows and a nice white milkshake. I replaced the O-rings in the upper gear case and pressure tested it and it held pressure, I didn't have a vacuum gauge so couldn't test it Ran boat about 10 hours and checked leg oil, again all milky pulled upper gear case and found that there was a seal for the drive shaft in there that I didn't replace as it was all rusted over and didn't even know it was there. Replaced the seal and O-rings and tested it again held pressure. ran boat again about 10 hours and checked oil again all milky. Drained all oil out again and pressure tested it. 15 lbs and the leg held it all day long. Went and bought a vacuum gauge and it will not hold any vacuum at all. I have tried to find the leak and can just not find where it is leaking from. I used a very small amount of silicone on all the seals and the drive shaft bellows when repairing it. I've got the repair manual for it and there is no info on finding vacuum leaks other then spraying heavy oil on it and watching for it to be sucked in. Pressure leaks was the soapy water test, and no bubbles as it held pressure. I'm thinking that it might be the drive shaft seal but how would you see if it was leaking when its all covered up with the bellows. Also is the a seal where the shifter cable enters the leg? I see just a backing plate and 2 bolts. Again nothing in the manual about seals there. Any help is much appreciated, thanks Casper

Re: Volvo 280 leg leak can't find?

You need a new bellows to keep the water out. Once you get water in the bellows, as the drive cools it sucks water in the drive through the seal. It's not designed to keep water out, it's there to keep oil in. Once water gets in the drive and the drive heats up, it pushes the oil and water mixture back into the bellows with the oil.

You may also need the seal washer on the ujoints. It can take out a new seal if rusty.

Re: Volvo 280 leg leak can't find?

The bellows only has about 10 hours at most. I've washed the bellows all out and inspected it and it still looks new with no signs of holes or wear. I'm thinking it might be the seal on the upper gear case that seals the drive shaft that is kept in place by the snap ring. The drive shaft had a bit of rust and pitting on it but I sanded it down to what I thought was smooth, But I'm thinking it was not smooth enough. This was the seal that I didn't replace the first time do to the rust covering it and not knowing it was there. This seal also only has 10 hours on it.
1) Do you think that the leak is in the upper gear case area as this is where the water was?
2) The shift cable clamp on the front of the intermediate housing I take it has no seal to let water in?
3) Is there any way to test the upper gear case by it self for leaks?

Again thanks for the help

Re: Volvo 280 leg leak can't find?

After removing the upper gear case today to inspect it, I see that the drive shaft does not come in contact with the seal it goes into a splined opening so that is not the problem.