Filer cap drain holes not draining, 1150

[scots_jon]

Hi All,
Filling with fuel today I noticed that the drain hole in the lip around the filler tube doesn't. I assume that the hole is there to allow rain water that makes it's way down the side of the filler cap to drain harmlessly away rather than ending up in my tank (probably also to deal with small spills when filling?).

I assume that it's just blocked with crud and I was going to blast some compressed air down it, but was worried that I would burst or slip a pipe inside the tank. I had a quick look round under the belly but can't see any obvious drain hoses.

Does that hole lead to a drain hose somewhere? If so where should I start looking? Or does it just lead to vent somewhere under the tank.

Don't know how long it's been blocked, but the bike lives outside so I assume that at least some water from the recent "showers" has ended up in the tank, is this likely to cause problems?

Cheers,
Jon.

 

[Nick Marshall]

think

it goes from under the tank, along the horizontal r/h frame near the front part of the seat, then exits near the r/h riders footrest with about 2 other black hoses...i think...

 

[Tarka]

From the hole at the filler neck ,it`s just a pipe that spirals around the filler neck fitting and becomes a black rubber pipe near the footrest on the right.


The other rubber pipe near the footrest is a tank breather/overflow.

Open the filler cap and blow through one of the pipes from the footrest end...if you hear a gurgling inside the tank,you`re on the wrong one.

The filler neck drain pipe can safely be blown through with compressed air from either end,as it`s nothing more than a straight through drainage path for water from the filler neck.

Occasional squirts of WD40- or similar from the filler cap end will probably keep it clear.

 

[Stujw70]

I use a large syringe (without the needle) to clear mine by pushing air through and once clear run some warm soapy water through it just to give it a good clean out.

 

[Spout]

...if you hear a gurgling inside the tank,you`re on the wrong one.

You'll only hear a gurgling if your tank is over full. The breather is at the highest point in the tank (through the rollover valve).
As everyone says - the two tubes by right footrest are the tank breather and filler drain.
Both run through the tank - so if either pipe pops off inside it can drain your tank.
So please don't be tempted to push wire down or use a high pressure air line. Simply blowing should free a blockage. If not pull the whole filler out of the tank and disconnect the breather and then clear it.

 

[Gas'd Off]

Last time this question came up and the subject of compressed air was mentioned someone warned not to be too vigorous with the airline as it's possible(if the blockage is tight) to blow the pipe off inside the tank. Worth knowing

 

[Welshman]

I use the WD40 to flush it, with the help of that 2mm nylon stuff you use on a lawn trimmer, it works well with less chance of holing the tubing than a piece of wire, or blowing it off with compressed air.

Welsh

 

[Womble]

If not pull the whole filler out of the tank and disconnect the breather and then clear it.

If you take the filler out of the tank, the O-ring that seals around the filler will pop out and won't reseal.

You need to put it somewhere warm and dry for a day for it to relax back into shape, or put in a new one if you're in a hurry.

 

[scots_jon]

If you take the filler out of the tank, the O-ring that seals around the filler will pop out and won't reseal.

You need to put it somewhere warm and dry for a day for it to relax back into shape, or put in a new one if you're in a hurry.

Hmm, I was thinkinging of pulling the filler out to clean and drilling a breather hole in the filler at the same time. But as the bike lives on the road, I can't really leave it without a filler cap over night

Is the o-ring a standard size (Viton, I guess?) so I can buy another one or do I need to get it from BMW?

Thanks everyone for all your help.
Cheers,
Jon

 

[Steptoe]

Hmm, I was thinkinging of pulling the filler out to clean and drilling a breather hole in the filler at the same time. But as the bike lives on the road, I can't really leave it without a filler cap over night

Just grease the O ring, and "twiddle" and press down on the the filler and it'll pop back no problem.

 

[Spout]

Just grease the O ring

Vaseline works a treat!

(I put forward that statement purely in connection with this thread )

 

[scots_jon]

Yeap, done it about an hour ago. Took quite a bit of tickling, blowing and sucking but I got the hose clear in the end.

Greased up the ring with vasline and it slipped right in. I can see that you could find it difficult if you try to put it in when it's not ready and adequately lubed though.

Cheers for all the help.

Jon