Need assistance on this one. Either a clever way to repair or make work my front brake reservoir or, if anyone has one they’d let go for less than what seems to be the standard price on eBay. I’m in WA as I know some of you guys are and I’d be thrilled to be able to pick one up. Thanks in advance!!

*’85 K100 RS 44k

The easiest thing to do so that everyone knows exactly which bike you have is to go to your Profile tab, enter the Signature tab, and insert the year and model of your particular Brick.

Now for the stripped thread...most BMW brake hoses and fittings use a 10mm x 1.0 pitch thread. Is the aluminium master cylinder thread where the hose goes in the bit that's stripped? Did the inside taper suffer any damage? Have you ever heard of Helicoil? They're trick steel thread coils that replicate, after drilling and re-tapping to a minimally larger opening, the original thread, effectively restoring the threads so you can continue using the item. I have used them successfully on spark plug holes. Won't it leak? Not if the taper is not damaged.

A place to buy Helicoil kits.

Thank you! I didn’t see a signature tab but I edited the op...
Exactly! The aluminum that the banjo bolt threads into is what is stripped. Was moving too fast reassembling and just over-tightened... a lot! I’m familiar with helicoils, I’m not sure what you mean though by the “taper”. Is there a taper in the threads similar to NPT? Anything I could use to seal the insert in the new threads? Loctite? Teflon? Seems it would take a small miracle to not leak under pressure otherwise. Although I can’t find anything online I can’t help but think there has to be a banjo bolt out there with a larger od that I could tap the stripped hole for. Saving the need for the helicoil. Is that worth pursuing?

jpatrickleighton wrote:I didn’t see a signature tab but I edited the op...

This is the window that opens when the Profile tab is clicked. The Signature tab is indicated by the arrow.


This is the window that opens when the Signature tab is clicked. Enter your moto's year of manufacture, its model and other pertinent information about it into the box indicated by the arrow then click the Save box at the bottom of the page.

If you have the space I would be tempted to use a threaded insert. A drill and tap process similar to a helicoil but a little bigger hole with and an insert with a complete set of threads inside and out. Many of them come with a thread sealer/locker on the OD threads.

https://dsportmag.com/the-tech/three-ways-to-fix-damaged-threads/

@laitch thank you! I think I got it figured. Tried adding a pic too. Seemed like it was a little big... we’ll see when I send this 
 
@gorio well I’m not sure how much materials going to need to be removed to get a Helicoil in But that’s definitely what I’m gonna try first at least go take a look and see if this, maybe quarter inch wall that I have is going to afford me enough room for it... fingers crossed!

I see you're parked above the Tacoma Dome. If you want to change that rear cowl so your '86-on seat doesn't haven't a gap where the grab handles go on the '83 to '85 models, I have several later cowls available, not in your colour, but that's easy to change.