Magic Volvo 120s saildrive oil drain o ring?

[Daydream believer]

I've heard this said a number of times on here but cannot see how its possible, assuming you are referring to a VP 120/130s or similar.

Whether you see it or not, it used to happen. I do not know why & never came up with a sensible conclusion. But could often feel the air going IN, not out as the seal on the filler released. No I do not overfill the oil. 120S saildrive.

 

[Ammonite]

Whether you see it or not, it used to happen. I do not know why & never came up with a sensible conclusion. But could often feel the air going IN, not out as the seal on the filler released. No I do not overfill the oil. 120S saildrive.

If the O-rings on the dipstick or filler are worn, they might release pressure as the saildrive warms up rather than letting it build up. When the drive starts to cool after a long run it could then create a vacuum that pulls the O-rings into place, sealing them. You'd need to test the theory.

 

[dod]

I did not call you a spanner monkey. i said it was not a job for one.
i have changed the seals 3 times now .
I would suggest that no leak prior to launch does NOT necessarily mean that the saildrive will be watertight.

3 times. Not all on the same saildrive I hope? Otherwise either you are not doing it correctly or you need to change your cruising area. Never heard of this rush of air in 25 years of saildrive experience. Think you should call Volspec.

 

[Daydream believer]

3 times. Not all on the same saildrive I hope?

First time out of necessity. Other times, along with saildrive main seal changes as preventative maintenance. The engine did 5000+ hours before it gave up, so more running than most.

 

[ollie1977]

I had water in the oil which I found one cruise when in Le Havre. The useless volvo engineer in Cherbourg told me it was shaft oil seals. But a phone call to Volspec engineer in Tolesbury said it was the washer on the saildrive drain. They were right. The volvo dealer in Cherbourg could not source a seal, so I took a thick neoprene washer from the top end of the pump handle spindle of my Jabsco Heads & used that. It lasted several years & several oil changes. The suitable seal is just a typical rubber ring one will find in your box of rings
The Volvo one is a skiny little thing & I now have half a dozen.

How did you know it was the oring on the drain hole that failed rather than the shaft seals?

 

[Daydream believer]

How did you know it was the oring on the drain hole that failed rather than the shaft seals?

Because the Volspec engineer in Tolsbury tipped me off & I decided to have the boat lifted in the yards lunch hour in Cherbourg (180 euros) change the o ring & oil myself & test it on the way to the cIs. It was the only available time & changing seals in Cherbourg was not an option. I wanted to get to a more reliable english based yard in the CIs.
No problem after that

 

[ollie1977]

Because I had the boat lifted in cherbourg & I changed the o ring I could only do this in the yard lunch hour then the boat had to go back in the water. It also meant I could do a full oil change before going to an english speaking dealer in the CIs to get repairs if needed rather than dealing with French.
When I got to St Peters Port the oil was fine

So by process of elimination I guess. Put of interest did you grease the replacement oring before installing. I am about to undertake the same procedure

 

[Daydream believer]

No
I would also point out that I had changed the oil at the end of the season --as I do every year. One should do as a general maintenance item.
Seals do not fail suddenly but over a period & I do check the oil before each cruise. This incident happened between Bradwell & Le Havre & the oil had just been changed & found to be clear prior to the trip. So a sudden failure pointed to the ring rather than shaft seal problem

 

[ollie1977]

Hi
Thanks for that. Sound advice which I intend to follow. One last question if I may. Does the o-ring sit on the drain plug nut or should it be placed in the housing before inserting the nut? I hope I'm correct in assuming we are discussing a 120s saildrive for volvo penta 2002. Many thanks

 

[searocket]

We have a 130S D, the part number as mentioned in #1, and it goes on the plug, a bit fiddly I find to remove the old one and persuade the new one past the threaded section.

 

[Daydream believer]

My first one was a 120s & just slipped over the plug on to the shoulder. I now have fitted a new 130 & I seem to recall that is the same.

 

[Ammonite]

The latest incarnation of the 120S workshop manual shows an o ring which is a loose fit on the drain plug but fits snuggly into a recess on the housing. This is what I have on my 120SD. Rather confusingly however the text suggests soaking the "gasket" in oil for 15 minutes which looks like a carry over from earlier versions which used a fibre gasket.

 

[Martin_J]

That always intrigued me. As you say, the manual for the 120S-D does show the fibre washer and mentions soaking it in oil before use.

My 120S-D leg seems to have a very flat surface around the edge of the drain hole and a flat surface under the screw head, both of which would look (in my eyes) to be perfect for a fibre washer.



Fibre washer or O-ring seem to fit.

Keypart include both an O-ring and a fibre washer in their kit for the 120S-D.



Is there a definitive answer as to which lower legs should use the fibre washer and which should use the o-ring?

 

[Ammonite]

That always intrigued me. As you say, the manual for the 120S-D does show the fibre washer and mentions soaking it in oil before use.

The version of the manual I'm referring to covers all versions up to the SE and has a picture of an O ring but talks about soaking the gasket in oil. As far as I can ascertain there are three gaskets/o rings available which are 804261 (fibre washer), and two sizes of O rings (955974 and 3855081), however confusingly all three are listed as compatible with the 120SD and 120SE and I think it depends on what version of drain plug you have and whether it is a magnetic one. There are at least two versions of this including 852904 and 3855082. At first glance it seems completely random but I suspect it depends on particular production runs, markets etc and you would need to check against the serial number for a definitive answer (or stick with what has worked in the past)