1976 1000ltd

[ausie]

I have oil leaking from a hole in the engine housing under the water pump . The hole is part of the housing but I have no idea what it's purpose is and why it is leaking oil. Can anyone give me some advice please?

[Rambozo]

It indicates that your seal has gone bad. To make sure the coolant doesn't mix with the oil, there are two water pump seals, one for coolant and one for oil, with a weep hole between them, so when a seal goes bad, it leaks to the outside instead of inside.

[ausie]

Many thanks. I will take the cover off and replace seal

[dingdong]

There is more involved than just replacing that seal.
viewtopic.php?f=11&t=275

[Rambozo]

Cyclemax offers a kit with all the gaskets and seals needed.
https://www.cyclemax.com/inc/sdetail/gl ... 809/158216
You might want to change the water pump while you are in there.

[WingAdmin]

It's the seal IN the water pump. Changing the seal on the gasket won't fix it, you have to change the water pump. As the other user mentioned, read up here: viewtopic.php?f=11&t=275

[Rambozo]

I thought the oil seal between the two pumps is in the front of the oil pump?

[WingAdmin]

I thought the oil seal between the two pumps is in the front of the oil pump?

The water pump is driven by the engine, by a shaft that comes through the front (pressure) oil pump. That (back) side of the water pump has oil flowing around. The front side of the water pump is subjected to coolant.

There are two seals inside the water pump. One seals the oil out (on the back side) and one seals the coolant out (on the front side).

If either seal fails, there is an escape channel that allows the fluid (oil or coolant) to escape, through the "weep hole" which is where the oil is leaking out in this case. This is intentional. Honda calls it a "tell-tale" hole because if there's fluid coming out of it, it is telling you that the seal in your water pump has failed.

Some people have seen oil (or coolant!) leaking out of this hole, thought "a leak!" and sealed it up with epoxy, and once I saw a wood screw shoved in there! Doing this means the fluid migrates through the pump and is forced out the other seal, resulting in oil in your coolant, or coolant in your oil, neither of which is a good thing.

Blue is coolant, green is oil

[Rambozo]

The thing is there should not even be any oil behind the bearings if the shaft seal in the oil pump housing and the case o-rings are doing their job. The bearings live in a sealed compartment, not common to the oil bath. Depending on the sealed bearing seals to keep oil out is not their designed function. The only way oil can migrate to the start of your green path is for the shaft seal in the oil pump housing, or the o-ring that makes the face seal to fail.

I did say to change everything since it is such an ordeal to get to this area, but I just wanted to be clear about what was failing to cause an oil leak.

Let's see if this works.

It did! The two red dots are the sealed points connected by the pump housings. O-ring to the left, shaft seal to the right. One of those would have to fail to allow oil into the bearings. And of course then it would follow your green path to the weep hole. As well as failure of the o-rings on the water pump body which would connect the oil bath to the weep hole if they failed. (the other green path)

[Old Fogey]

Water pump rebuild kit here:
http://wingovations.com/water-pump-rebu ... 4592289895