Oil Tank Connections

[gblwy]

Hi,

I have a slight leak from the inboard oil line connection to the oil tank. I believe it is a tapered connection.

On my installation the oil line fitting can be tightened right down to the neck on the oil tank. When I run the engine, oil weeps from this connection and collects on the rim of the tank, then overflows onto the battery box.

I have tightened the joint as much as I can but it still weeps. It seems to me that the two connections are preventing the taper from fully engaging. The only way I can see to fix this is to grind some material from the oil line fitting which seems a bit extreme.

Anyone any relevant experience, ideas?

First flight today with me in the driving seat - full throttle yielded 5520 rpm and 118 kts indicated - that's without spats. Cold outside though.

Thanks...Keith

 

[Mich48041]

Oil Leak

Keith,
Have you fixed the oil leak yet? I vaguely remember having a leak, but can not remember how I fixed it. I looked at the fittings and see that I did not modify any parts. While tightening the fittings, it might help to loosen the over-center clamp that holds the top onto the tank. Doing that could make it easier to align the fittings. You could put a little Teflon paste pipe dope on the male fitting, but not enough to contaminate the oil.
Joe

 

[gblwy]

Oil Tank Lid Fittings

I think I have identified why my oil tank connections leak.

The oil lines have female fittings, and so does the lid of the oil tank.

Does anyone have an oil tank they have not yet fitted? If so, could you look at the inside of the IN and OUT fittings on the top of the tank and advise whether these have male or female mating surfaces?

The drawings on the plans indicate male fittings on the oil tank lid, but the Rotax parts manual seems to show female fittings.

Thanks...Keith

 

[iain donnelly]

oil tank JIC fittings

mine are the same but Gus at Vans sent me pictures of a tank with male JIC fittings but parts manual shows only female fittings I think i,ll have to modify my hoses

 

[gblwy]

Thanks

Thanks Iain.

The oil tank comes with two 90-degree oil line fittings, which obviously match the tank. One of these can be used to replace the fitting in the Van's supplied oil line (the OUT one). You need to purchase a straight fitting for the IN line, and obtain a couple of steel jubilee clips.

Conair in the UK are sending me the straight fitting and a couple of clips, for £18. This should do the trick if I can cut off the steel crimps on the oil lines without damaging anything...

Still mystified at the non-standard oil tank top, which isn't in the Rotax spares catalogue.

Cheers...Keith

 

[gblwy]

The plot thickens...

Every Rotax installation I have seen uses rubber oil hoses and push-in connections secured with hose clamps.

Vans oil lines are hydraulic hoses, with steel braid and with swaged connections good for 2000 psi or thereabouts - and a fire sleeve on top. Way over the top. Both ends are AN818 fittings. I am still mystified as to how Vans connects these to female metric units on the oil tank.

Anyway, I ended up removing my lines and taking them to Pirtek who make hydraulic hoses etc. I had them take the longer of the two hoses, chop the end off so that it matched the length of the shorter hose, and had a metric fitting swaged on.

I had to have a complete hose made up to replace the savaged longer hose. AN818 at one end and metric at the other. Cost me big bucks.

It is essential to ensure the two ends of the hose that connects to the oil cooler are oriented correctly. The steel braid means that the hose is virtually impossible to twist to fit.

It is also essential to ensure that you use the original or an equivalent fitting at the bottom of the block. Otherwise the fitting will foul the exhaust silencer - ask me how I know.

More and more reasons why it makes logistical sense (if not necessarily financial sense) to accept the engine delivered by Vans as part of the kit.

Cheers...Keith

 

[Gagarin737]

Because of your mail I decided to order with VAN'S instead of buying an engine locally. If I did my homework correct it is even cheaper while it crossed the ocean twice
Delivery in march.

 

[rvbuilder2002]

Every Rotax installation I have seen uses rubber oil hoses and push-in connections secured with hose clamps.

Vans oil lines are hydraulic hoses, with steel braid and with swaged connections good for 2000 psi or thereabouts - and a fire sleeve on top. Way over the top. Both ends are AN818 fittings. I am still mystified as to how Vans connects these to female metric units on the oil tank.

Anyway, I ended up removing my lines and taking them to Pirtek who make hydraulic hoses etc. I had them take the longer of the two hoses, chop the end off so that it matched the length of the shorter hose, and had a metric fitting swaged on.

I had to have a complete hose made up to replace the savaged longer hose. AN818 at one end and metric at the other. Cost me big bucks.

It is essential to ensure the two ends of the hose that connects to the oil cooler are oriented correctly. The steel braid means that the hose is virtually impossible to twist to fit.

It is also essential to ensure that you use the original or an equivalent fitting at the bottom of the block. Otherwise the fitting will foul the exhaust silencer - ask me how I know.

More and more reasons why it makes logistical sense (if not necessarily financial sense) to accept the engine delivered by Vans as part of the kit.

Cheers...Keith

Keith,
If you do some research you will find that there is two different oil tank tops available from Rotax. The original has the fittings that you describe, and the newer one has UNF style fittings meant for standard aircraft grade hoses.

If you are only finding one, then you are looking in an old Illustrated Parts Catalog.

The new style tank was to meet the ASTM standards for LSA in the U.S., and this is what Rotax supplies if you purchase an ASTM compliant engine

I didn't know you where operate your engine with Vans supplied hoses connected to an early style tank. You are very fortunate that all you had was an oil leak.

This is just one reason that purchasing an engine for an RV-12 from somewhere other than Van's, without having a lot of knowledge about what you are buying can actually lead to spending more money.

There are old threads here in the RV-12 forum where I explained some of the issues. I think it was someone in South Africa considering buying a local engine.

Side note... my personal experience with the clamped on hoses is that the new way is far superior. The clamp on hoses are a constant source of oil leaks. With the ASTM compliant hoses... never a leak.

You are also correct about the clocking of the hose ends being critical. The hoses supplied to builders that purchase a power plant kit that have a 90 degree fitting on each end, have the ends installed with a very specific clocking relationship.

 

[gblwy]

Enlightenment

Thanks!

I was unaware I was looking at an old parts catalogue. I was looking at the Rotax site, and didn't see any mention of an updated tank.

With the benefit of hindsight, I would have ordered the engine from Vans.

Cheers...Keith