I was having trouble bleeding the front brakes and this did the trick, just bang 10 psi on via a stirrup pump, not sure if this is the done thing or not???

G'day, some time ago I was having the same problem. I finished up putting the bike on the side stand and turning the handle bar to the left so the brake fluid reservoir is at the highest point. Take the brake fluid cover off the gently start tapping the brake lever. Tiny bubbles will start floating to the top. Keep doing this for about 5 to 10 minutes or until no more bubbles appear. Works a treat. Cheers Tom

I used to  pressure bleed, but I now vacuum bleed with my home made bleeder.

Tom Grabau wrote:G'day, some time ago I was having the same problem. I finished up putting the bike on the side stand and turning the handle bar to the left so the brake fluid reservoir is at the highest point. Take the brake fluid cover off the gently start tapping the brake lever. Tiny bubbles will start floating to the top. Keep doing this for about 5 to 10 minutes or until no more bubbles appear. Works a treat. Cheers Tom

That worked for me too.

Richard.

I bought a cheap vacuum pump off ebay. I works a treat. A good bleed, very fast, with minimal fuss. Even on the K1100RS after disconnecting the ABS.

In addition to putting it on the center stand and turning the bars left, you can also loosen the screw that holds the throttle perch and rotate the perch so that the hole in the top of the master cylinder is the highest point. Then slowly squeeze the brake lever to get any air bubbles out.

Tie the lever hard back against the handlebars and leave it overnight. Or hang a dirty great weight from the foot pedal if doing the rear brake. I've never figured out the theory behind this one but it does work.

I agree with Cpt. Holister that vacuum bleeding is the way to go. The Mityvac vacuum bleeder is well made and will last a lifetime being made of precision die cast metal. If you are getting nowhere in terms of shifting stubborn air bubbles often the best thing to do is leave the system overnight and usually the stubborn bubbles will have purged themselves.

Many thanks to MartinW and neighbour Dave for helping me with brake line replacement today - an hours job turned into 6hrs!!! Thanks for perseverance and patience and willingness to share knowledge, tips and tools.

I had replaced rear line and reservoir hose all ok but had a poor bleed. Left it and moved onto front. All went well until MC line to steering head...didn't seem to fit. Put old one back on and spent an hour getting enough brakes to get around to Martins place to use his (kindly offered) vacuum bleeder and experience.

The new line supplied was never going to fit....Daves neighbour is a hydraulics line fella and made me up a new one that afternoon (mighty effort and much appreciated). A good hour or more trying to bleed (including a leak and banjo bolt alteration and multiple wasted crush washers) fixed the leak but still couldn't get firm brakes. Got enough brakes to make a cautious ride home.

Put on centre stand - steering full lock left, took cap off MC reservoir and taped lever for a couple of hours...Got some bubbles...put on side stand full left lock and squeezed lever, last stubborn bubble out.....Thank you K100 forum!!!

Brakes are as hard as.....well many things.

Again thanks to Martin and the forum for sharing the wealth.

Cheers Mick

Good to hear Mick 

I had to roll the perch to get the last bit of air out 

How do you like the higher bars ?

Dai wrote:Tie the lever hard back against the handlebars and leave it overnight. Or hang a dirty great weight from the foot pedal if doing the rear brake. I've never figured out the theory behind this one but it does work.

What this does, well the theory is, that pressure applied to either front or rear brake and held overnight is supposed to assist with reforming lazy brake piston seals.  It can help reseal a leaky brake piston only if the seals are reasonably good and just ever so slightly out of round from lack of short term use.  I have found it can work.
Cheers.