Update of the rubber lines that supply oil to the cylinder head

[bdouvill]

Hi guys,

I plan to remove the engine from the frame on my Bandit 400 during the Christmas period to check the gearbox output bearing that I highly suspect to be worn out. In the process, I'd like to take this opportunity to fix some minor issues like the leaky rubber lines that supply oil to the cylinder head:
http://www.pieces-suz.com/thumbs/s/moto_img/suz_img_7/660_500/dp015553.png
I refer to items #5 and #6 that are apparently discontinued items. Furthermore, their price is highly exaggerated (like 70 euros each)...

I have been looking for a while for a nice solution like this:
http://www.restom.net/resizer.php?src=photos/produit-1224784789-1224784797.jpg&width=1120&height=805
The picture is apparently from a Kawi ZRX 1200 which is aircooled so better to have a good oil cooling system :-)

Anyway, my problem is:
1/ I don't know exactly the size and thread of the output (at the bottom) and the 2 inputs (on top). I changed the copper gasket to start (but it got worst...) so I noted the bottom seems to be 10mm and the top 8mm but this is just a guess.
2/ When I search on the internet for Goodridge parts (that seems to be well known in race cars/collection cars world), I mainly find some items with non metric size (like 3/8, 1/2 and so on) and I am not sure what would fit. I believe Japanese manufacturers are using metric system, aren't they? Should I try to find male Metric to male US adapter to fit a male connector on it? If M8 adapter is needed, then I was not able to find it.

Any guess on that matter? That would help me clarifying what I am looking for.
Thanks in advance for your help ;-)

[greg737]

Anyway, my problem is:
1/ I don't know exactly the size and thread of the output (at the bottom) and the 2 inputs (on top). I changed the copper gasket to start (but it got worst...) so I noted the bottom seems to be 10mm and the top 8mm but this is just a guess.

Are you saying that the oil line itself is leaking?  Or are you saying that the line is leaking at its connection to the cylinder head?  Or is it leaking from its connection to the crankcase?

It sounds like you're saying you've got a leak from the point on the cylinder head where the oil pipe union bolt attaches to it, because you mention replacing the copper gasket on it.

The fact that you say the oil pipe union bolt leak got worse when you tried replacing the copper gasket (would the term "crush washer" be more appropriate?) makes me worry about the state of the threads in the aluminum of the cylinder head.

If there's a problem in the interface between the oil pipe union bolt and the threads in the cylinder head that it screws into the problem is almost certainly with the cylinder head threading rather than the bolt because the cylinder head is aluminum while the bolt is steel (soft aluminum vs. hard steel).

The relatively soft aluminum of the cylinder head vs. the much harder steel of the oil pipe union bolt is a recipe for damage due to over-torque of the bolt or perhaps some sort of cross-threading of the bolt during installation of the oil pipe union bolt, especially when an inexperienced mechanic is wielding the wrench.

When you pull the engine in December you should do a very careful inspection of the oil pipe threads in the cylinder head (if this is where your leak is coming from).  The good news is if you find a damaged/stripped/crossthreaded situation it can be repaired pretty easily with a Helicoil thread replacement kit (a do-it-yourself solution that really does work well) or with a Timesert thread replacement insert which is more expensive and is usually done by a machinist at a machine shop.

[bdouvill]

Anyway, my problem is:
1/ I don't know exactly the size and thread of the output (at the bottom) and the 2 inputs (on top). I changed the copper gasket to start (but it got worst...) so I noted the bottom seems to be 10mm and the top 8mm but this is just a guess.

Are you saying that the oil line itself is leaking?  Or are you saying that the line is leaking at its connection to the cylinder head?  Or is it leaking from its connection to the crankcase?

My guess is that the line is leaking at the jonction between the rubber line and its metallic "connectors" (no idea how you call that in english, this is the same kind of connector than on braided brake lines). If this is correct, it got worse since I simply manipulate the lines to measure their length and I believe the rubber is dry after 20 years so did not like that. Does that make sense?

Anyway, I'll check the thread but I usually take care so I believe I was cautious when I replaced the copper gaskets. Do you have any idea for upgrades?
Thanks again Greg 

[bdouvill]

I'll post a picture as soon as I can take one (this is night time now).

[greg737]

Do you have any idea for upgrades?

Any medium-to-large sized city will have (absolutely has to have) one (or even two) industrial hose supply businesses.  Here in Spokane, WA we have a place called "House of Hose".  These guys are experts in fuel, hydraulic, water, refrigerant lines for the various applications that the local economy requires.  They have a large inventory of parts and they can construct high quality, high pressure lines on-site in just minutes.

I think you could probably find a very similar business in your city.  They could make up a replacement set of hoses for you.

[greg737]

My guess is that the line is leaking at the jonction between the rubber line and its metallic "connectors" (no idea how you call that in english, this is the same kind of connector than on braided brake lines).

I think the word is "Swage".  Although, as a noun it refers to the item that does the compression of the connector fitting collar onto the line, but used as a verb it describes the act of attaching the connector fitting collar to the line which is close enough for what we're talking about here.

[vintagemilano]

Greg is totally correct in everything he says here. You may have to wait for the hose shop to bring in the correct banjo fittings for the ends on the hose. Depends on the size of your town.

[bdouvill]

Hi guys,

I know I started this thread like 2 years ago but it did not stop bothering me since. I browsed the whole Goodridge catalog and no oil line stuff fits this since it's too small. I contacted a UK dealer specialized in all this kind of stuff and they advise that I use brake/clutch lines for that.

Here are a few pics.

With the old lines:



Both lines were leaking at the junction of the hose and the fitting:









The setup is rather clean (considering that I never assembled such lines before). When I sit on the bike, I can not see the line so it's not wider than the frame. More important, the leak is now gone and I am super happy. Lines are hot after my daily ride to work (15') and I already drove like 1000 km since then.

I hope this will be useful for someone. If needed, I can share the references of the parts I ordered.
See you.

[ventYl]

Did you try by any chance to get touch wit companies making custom lines? My carb tune set comes from one such company. They are doing a rebuild of various pressurized lines. They only need to see the original line and know what is the medium inside and what is the pressure (or use). Sure it will be more expensive than some 3rd party lines but maybe cheaper than OEM ones.

[greg737]

Benoit, How is your other project bike doing, the VFR?  I just purchased a '99 VFR800, a one-prior-owner bike in very nice shape with only 19,000 miles on it.  It runs great but the prior owner was putting off some of its maintenance needs.  The valves have never been checked/adjusted, the forks have the original oil in them, the starter valves have never been synchronized, the wheel bearings have never been checked/re-greased and the steering head bearings have never been serviced.  I'm actually looking forward to doing the work to bring the bike up to top condition.

[bdouvill]

Benoit, How is your other project bike doing, the VFR?  I just purchased a '99 VFR800, a one-prior-owner bike in very nice shape with only 19,000 miles on it.  It runs great but the prior owner was putting off some of its maintenance needs.  The valves have never been checked/adjusted, the forks have the original oil in them, the starter valves have never been synchronized, the wheel bearings have never been checked/re-greased and the steering head bearings have never been serviced.  I'm actually looking forward to doing the work to bring the bike up to top condition.

Greg,

Good to hear from you. VFR project has been on-hold for 6 months then restarted slowly. You can follow it here:
http://www.vfrdiscussion.com/index.php?/forums/topic/82421-trying-to-revive-a-1993-vfr-750-incomplete-and-flooded/&page=1.
Hopefully, B400 still stands and does a hell of a job for a 24 year old / 91000 km on the odo girl.
Your VFR looks goods and you seem to have less work than I do on mine ;-)
Don't hesitate to share life with your VFR as well, even on other (VFR specialized) forums.