Oil return channel clogged?

[Martin]

It should be possible to resleeve the shaft by under cutting, then press on a suitable stainless sleeve or slightly over size, and machine to size. An old shaft would be a good starting place to experiment on. A good engineering works could do it but it probably would not be financially  viable. Has anybody got the equipment to give it ago, I would give it a try but I am too far away and freight costs would kill it. I can't believe nobody has tried it.
Regards Martin.

[BermudaBrick]

I took the shaft to my local independent motorcycle shop and although they weren't familiar with the design of the pump, they did put the shaft in a lathe and cleaned it up.  I'm starting to think it might work...

[Scud]

It looks like you have removed the surface corrosion - but it the shaft also pitted?  I read about filling pits on fork tubes with super-glue, then sanding the areas down to create a smooth surface. While I have not done this myself, I am thinking about giving it a try on some pits on my forks. The difference for your part is that it only needs to go through a seal once, while the forks pass through many times.

Home-remedies aside, if it were my bike and if I hoped to get a lot more trouble-free miles out of it, I would incur the extra expense now and replace the shaft.

[Bill]

Careful Scud .... Nobody likes to be told 'get the shaft'

[BermudaBrick]

It looks like you have removed the surface corrosion - but it the shaft also pitted? 

Yes, it is a bit pitted.  However, the pitting seems to be in the "air gap" between the seals and the impeller.  I guess I wasn't as concerned with the shaft passing through the seals during installation, but more concerned with where the seals sit after instalation and if they would seal properly.  It looks to me like they'll be sitting on good metal...?

[Scud]

The only way to know is to install it and see how it does. I suppose your smallest risk is your time - that you will have to redo your work. If the seals do leak, you should be able to see some oil in the water.

The larger risk is water in the oil. Here is a picture of damage to a K75 engine block where a bearing overheated. This engine had 180,000 miles, and when I took it apart, there was water in the oil. It's not hard to imagine how water in the oil can turn to steam in a bearing and prevent lubrication. I am not certain that water-in-oil was the cause, but that's what I found when breaking the bike down.

[Laitch]

Scud has summed it up. The reason to smooth that shaft section is to keep it from scoring the seal when it passes through it during installation. I think you'll see dripping from the weep hole at the bottom of the pump case if a shaft seal has been damaged during installation.

Both Scott_ and Tim make important relevant observations in this thread.

[Bill]

It is my understanding that it is the glycol that displaces the oil and without actually getting the engine warm damage occurs.  The GM Vega engine used nikasil treated aluminium blocks but cast iron heads ..... head gasket leak >>>> destroyed engine. The K engines use the same process !

[Laitch]

The BMW K-Series—Not Your Daddy's Vega. Ride One Today!

A missed advertising pitch, for sure.

[Bill]

Well I had one ... swapped a 327 C.I.  (5.3 L) chevy small block into it ...... big upgrade from 2.3 litre.

[alcorelli]

I did the same thing. 73 Vega was my first car. With the 327, it was nice.

[Scud]

It is my understanding that it is the glycol that displaces the oil and without actually getting the engine warm damage occurs.  The GM Vega engine used nikasil treated aluminium blocks but cast iron heads ..... head gasket leak >>>> destroyed engine. The K engines use the same process !

Yes, that's correct. I should have written "coolant" rather than "water" in my post. As I understand it, the shaft in question drives both the water pump and oil pump. A bad seal or worn shaft increases the risk of mixing oil and coolant - which you wouldn't know about until too late (or unless you add checking coolant to your pre-ride checklist).

Personally, I think the $200 expense is warranted if you intend to keep the bike for a while and ride it a lot more. If it's on it's last legs and you're just trying to eek out a few more miles before you sell the parts, then it's a different story.

And if you can get from there to putting a small block V8 in a Vega... well, that's just champion-level thread-drift.  :clap:

[Martin]

Rather than risk damage to the seal I would fill the pits with something ,eg liquid metal, JB Weld 2 part epoxy.. Maybe  the local Motorcycle shop could machine down the filler again for you. It would be a shame to get this far and damage the seal.
Regards Martin

[BermudaBrick]

An update on my water/oil pump adventures:  I talked again to my local shop and they were mixed on reusing the shaft.  One tech said, "if it were my bike I'd be hard pressed to spend $200 on a new shaft.  I'd try it and see."  The owner said it was "up to me".  Meanwhile, while I was perusing the fiche at MAX BMW I saw they indicate the need to purchase a spacer bushing and use the new-style impeller with the new seals.  Their diagram, when you look at the mechanical seal (part 7), says "only in conjunction with:" and then points to the spacer bush (which was not present in my pump).  Then looking at the impeller (part 13), it says: "When replacing the seal and spacer behind this, you must also replace this impeller if you do not already have the one in the photo. The old style (cast) impeller will not work with this assembly."  I have the cast impeller.

I don't see why the revised seals would require a different impeller so I called MAX, but the guy I spoke to basically read back to me what is on the site.  When I pressed him further his response was, "well, that's what it says so BMW must have a reason".  My local dealer's fiche does not say this.  Hmmmm.

So I searched around a bit more on this new development and found that Motor Works in the UK has a rebuilt pump!  Looks like I can score it for not much more than a new shaft:  https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=ENC61177&x=16&y=6

Have any of you dealt with Motor Works before?  Should I be worried about warranty issues or anything with it being purchased from a UK outfit?

[Martin]

I have got a lot of stuff from Motorworks mainly new, but a couple of items used. Prices can vary depending on condition, you can ask for as new. I have had no problems with them, apart from the fact I have to phone them with my Visa card number. I can't seem to pay on line. I will continue to deal with them.
Regards Martin. :clap:

[BermudaBrick]

I have got a lot of stuff from Motorworks mainly new, but a couple of items used. Prices can vary depending on condition, you can ask for as new. I have had no problems with them, apart from the fact I have to phone them with my Visa card number. I can't seem to pay on line. I will continue to deal with them.

I had the same problem, Martin.  I had to call them directly after trying 4 times.  The pump I ordered from them arrived today (very fast delivery), but I'll have to say I was dismayed at the condition of the pump!  Mine looks great - paint is fine and the surfaces look good.  The Motorworks pump looked really rough and hardly had any paint on it at all.  I'm sure it is what is on the inside that matters (new seals, etc), but I taped it up and hit it with some hi-temp flat black spray paint I had in the garage.  Seems like you want some protection from the elements, right?

RTV has never been my friend, so I sure hope it seals completely.  I don't see how one can keep sealant out of the oil return channel if your bead is all but a thin thread.  I tried to use as little as possible, so I sure hope it worked.  We shall see tomorrow...

[Martin]

Hope it's all OK, you might want to mess around with the old shaft to see if it possible to do a repair. There must be away that doesn't cost an arm and a leg. If the surface where the seal runs is OK you only have to worry about damaging the seal on installation. It might be possible to repair with epoxy, JB weld or something else. I had a mate repair fork pitting with I believe a US product called Cronobraze 92C, that could be worth a look.
Regards Martin

[BermudaBrick]

Filled my K up with oil and coolant this morning and started her up and... the rebuilt pump from Motorworks seems to be doing its job - NO LEAKS!  :2thumbup:  I ran it in the garage (terrible weather today) until the fan cycled 3 times and saw no drips of anything other than the rain outside.

Thanks to everyone for all the advice, etc!   :clap: