lost all the fluid in the rear brake!

[Troyskie]

riding home day before yesterday I lost all feel in the rear brake . This is bad right now as my main road home is slimy mess while they re-surface, in rainy season . Normally the rear is pretty underused by me & it's lack wouldn't cause me to stop riding.
I checked the obvious things like how much fluid in the reservoir etc. No clues. But the reservoir was totally empty. I suspected a mistake in installing my new braided lines.
Checked, all good .
Hmmmmm.....found a drop of fluid on the floor that wasn't there before beginning the inspection. Traced it up & bingo! The spigot from the master had snapped completely, but was held in place by the hose and all the fluid went out, barely touching the bike & not leaving many spots to find it.
I checked with the local Yamaha dealer how much a new master was, $286, hmmm, can I get the plastic spigot only? Of course not. Can I get a new master at all? No. So a quick call to Joes wreckers down in Canberra, yep, $60 plus post. My work has a courier pick-up everyday just 5 min away so we arranged for them to grab it for me. Arrived yesterday.
Pulled the old one out, installed the 'new' one (looked in pretty good nic to me). Fingers crossed it doesn't need a seal kit, Genuine are $118! Did a re-load of fluid and bleed, all good .
I checked with Glenn at Glenn Henrys, 'is this a symptom of a larger problem?' I asked, 'Nope', he replied, 'you have a 31 year old bike'
Here's a pic of the problem part. A close inspection showed the fatigue was there for a long time. It was probably finished off by installing the new braided lines as the hose clamp was likely re-tightened and caused it to finally let go.
Anyone else had this issue?

[FJmonkey]

You are the first one that I know of to report this failure.

[red]

Troyskie,

That plastic fitting can be repaired in several different ways, so keep what you have there as a spare parts assembly. 
Glad you found another one, for your bike.

Cheers,
Red

[aviationfred]

You are the first one that I know of to report this failure.

We can list this as the 2nd occurrence. About 2 months ago, my rear master cylinder broke in the exact same place. As Troyskie mentioned. In my everyday riding the rear brake gets very little use. I went to use it and the pedal just keep going further down and zero braking action. I had no drips/puddles/or any indication that something was wrong.

The only source for a replacement is other owners, or eBay.

Fred

[The General]

That`s interesting Troy. (Will take a closer look at mine.) But what I really wanta see is the shed with a  granite benchtop that has an underslung wash bowl cut inta her!!   

http://www.fjowners.com/index.php?action=dlattach;topic=13952.0;attach=4313

[Troyskie]

I've found the reason for the failure, and it is likely worth checking out yours. At my work we make a few ABS and PVC injection moulded parts.
If kept out of the sun they are good for decades & will be at about 20% of their flexibility and impact strength after 80 years.
Some back-yard SG testing suggested this part is ABS. ABS does not like the sun, even with stabilisers.
If you look at the sheer point, in the photo above, it is below where hose connects. This section can be occasionally in the sun, particularly when the bike is parked on the side stand.
As this bike had been parked up for collectively 19 years I can only assume there was a reasonable time when this part may have been repeatedly exposed to a little sun.
Also this section of the part will cop some torque when removing or working on the rear brake master or peg hanger mounting points, plus there might be some tension left when fitting the hose to the reservoir.
In summary, if this part fails you lose the rear brake, but it is not the end of the world. I suggest painting it in black to protect it from the sun. Even black electrical tape should do. Have a good close look if you can before covering it up to try and see if there are any hairline cracks. I was lucky enough that all the fluid dumped onto the swingarm then onto the ground and only a little got on the tyre.