Oil filler cap solutions?

Hi all-

I've had the leaky oil filler cap issue with my '96 1100GS for several years. I've changed out the o-rings, filler neck, and cap, and the issue always returns. Wiping out any particles helps for a short time. It's time for new riding pants, so it's time for a permanent fix to this issue!

A search of posts on this site revealed the Wunderlich cap replacement for $89 (link below), and I'm about ready to order it, unless there are other creative solutions to try first.

http://www.wunderlichamerica.com/motorcycle/R1100GS/8500064.html

How about it? Anyone got any ways to stop the chronic leakage without spending the money? If the brain trust here says ponying up for the Wunderlich cap is the best route, I'll do it.

Thanks for the help-

Keith

I bought a 1200

Seriously though, I know what you mean. The one on my RT leaked like hell for years. I did the same as you with the new filler neck, cap and O-rings. It still leaked eventually. I finally ended up replacing the factory O-rings with ones I found at the hardware store. They were a little bit thicker and seemed to seal tighter. No more leak

+1 = "found at the hardware store"

i thought i was gonna get a hernia pushing in the one i found.

NO leak in 2 years

Here is an alternative to the Touratech cap. I found it on eBay. No connection to the seller. $27.99 including shipping.

http://www.ebay.com/itm/BMW-R1150RT-R1150GS-Basic-Aluminum-Oil-Filler-Cap-R1100RT-R1100GS-R1150-R1100-/131039920494?pt=Motorcycles_Parts_Accessories&hash=item1e8296816e&vxp=mtr#ht_861wt_816

I got the Wunderlich solution and I'm very happy with it. Dry as a bone and added security from the casual vandal.

We serviced over a hundred Police bikes at the peak of the 1100/1150 run. Think of those shiny, expensive boots with oil on them.

We treated the o-rings like valve cover gaskets.

Filler cap o-rings got replaced every 6k. Filler base o-rings at 12k.

The plastic filler piece will crack eventually so every once in a while, a new one is required.

That's probably too often for civilians, but it kept the peace for good customers who carry guns and is not very much money.

My filler cap is seeping now so I ordered 4 filler cap o-rings and 2 filler base o-rings today to have on hand.

The aftermarket fillers will leak too and you run the risk of losing the "special key" to remove the cap.

Really, has anyone ever heard of a band of vandals messing with people's oil filler caps or putting foreign objects in anyone's valve covers?

I haven't.

My 1100S had signs of oil leak when I bought it. I figured it was something simple so I bought it. I found out it was the oil filler area. Ithad the Wunderlich cap. I changed O rings, I swapped to a new OEM filler with new O rings, wiped them clean etc. Finally swapped the vavle cover out with a scarred one from my RT. No more leak. Even put the fancy filler cap back in. No leak. Defective casting maybe?

Like others, I used a replacement O-ring from a non-BMW source. Most rubber swells slightly when exposed to isopropyl alcohol, so when I remove the filler cap, I clean everything thoroughly with 91% isopropyl; so far this combination is working quite well. I also use the stuff to wipe down the fork tubes.

OK, thanks all, I'll head for the hardware store and check into a slightly thicker filler neck o-ring. If not there, I can source through a supplier we use at work.

Ride safe-

Keith

Let me know what Hardware store, just got back from ACE and had no luck.

http://www.theoringstore.com/

Not sure what size you need, but it's not hard to measure them. Or you can send yours in for measurement, and request a few sizes that are a little thicker.

My 2003 RT has also been leaking from the oil filler hole. I just replaced the two O rings and the plastic insert. I'll let you all know if that changes anything.

 

Alfred

Mine on my '04 RT was weeping for some time. Replaced both o-rings and problem solved.

I learned the hard way that over tightening will cause 'em to leak.

So, after a 4 hour spirited ride, no drop in oil level. Previous 4 hour rides would take the level down at least half a cup. Maybe replacing the O rings and plastic insert should be part of yearly maintenance?

Just a couple of quick things I didn't see mentioned here.

If your sourcing your own o-rings from anywhere for oil based sealing, make sure they are made from the material FKM (Duponts trade name is Viton). Also, this may be folklore, but it always worked for me. If you put the factory fill cap in backwards such that the top of the cap doesn't look to sit in-line with the fins of the valve covers, it tends to seal better.

Shawn

I replaced mine on my r850r with the stock BMW parts. Whole assembly replaced and now it doesn't leak..