MKIII rear brake bleeding

I rebuilt the caliper and master cylinder on my MKIII and also put in a new hose. Hose is tied down so it is not higher than the caliper. i am having difficulty bleeding out the air.

I was careful to thread all the master cylinder and brake pedal components exactly as before.

I have never had any issues bleeding my front brake (also overhauled everything)...but this is the first time I did the rear.

Any advice would be greatly appreciated. Thank you all.

Keep at it. I have recently rebuilt the rear master on mine and relocated the brake light switch to between the battery and the rear fender. The line goes up over the rear end of the main frame tube and snakes down behind the oil tank to the rear caliper because I have right-side shift and have converted the brake lever and m/c to left sided. It just takes awhile to chase all the air out of the line and all the junctions. The front is just so much easier because the m/c is at the highest point and the caliper is at the lowest, allowing gravity to assist.

Danno, I've been at it for a while. Any tips as to how you did it?

Thanks.

When I run up against something frustrating, I tend to leave it alone for a while and then give it another go later. Tempers the frustration and keeps me from cursing too loudly and throwing tools. It's made easier by the fact that I've had this bike for 42 years and it's been through several different makeovers, so I can walk away and leave it alone for a couple of days and come back refreshed. I went so far as to pull the m/c off and disassemble it to make sure I did everything right because the overhaul kit came with an extra rubber washer that went unused. It's in a bag now and eventually the lever started getting resistance. I probably pumped a whole bottle of DOT 4 through the system before I finally got a good result.

Well the brake is bled but not performing well. I figure it's either the pads (bought them 40 years ago and recently found them), or the cylinder wasn't threaded in enough (though I installed it exactly as it was before). I believe this will impact the amount of pedal travel.

Can anyone tell me the amount of rear brake pedal travel on their mkiii?

Thanks for any help.

Nuno,
Had the same thing happen w/ mine. I measured and marked the location of the cylinder on dis-assembly. It was still off by 1 turn when I put it together. In my case, no matter how hard I pressed on the brake lever I did not have enough pressure.
I believe I backed mine out a turn. What ever you do be carefull. Too much in the wrong direction might cause the brakes to lock. If you want I can take measurements later, but if I remember correctly the travel was the same wether it worked or not. It is the location of the cylinder in the M/C body that was the issue.
I actually removed the entire system as on unit and bled it on my work bench, keeping the M/C lower than everything else until I was convinced it was free of air. Good luck.
Pete

Got it resolved a few weeks ago. I had originally put together the master cylinder assembly by carefully counting threads and rebuilding the relative positions exactly as they were before.

After seeing Pete's comment (thank you!) I did it over again following the Lockheed manual L.A.B. had previously sent me (thank you L.A.B.!). The master cylinder wound up being 1-2 threads further out from the housing.

Thank you all for your help Danno, Pete & L.A.B.

nberg said:

Got it resolved a few weeks ago. I had originally put together the master cylinder assembly by carefully counting threads and rebuilding the relative positions exactly as they were before.

After seeing Pete's comment (thank you!) I did it over again following the Lockheed manual L.A.B. had previously sent me (thank you L.A.B.!). The master cylinder wound up being 1-2 threads further out from the housing.

Thank you all for your help Danno, Pete & L.A.B.

Click to expand...

Hi, I need that manual, does someone have it ?

jimbo said:

Hi, I need that manual, does someone have it ?

Click to expand...

never mind, found it, right above!
http://www.classicbike.biz/Triumph/Main ... Norton.pdf