I have read all the postings about getting air out of the system and I believe that there is no air in the hydralics. My brakelines are braided and not. The line from the master cylinder is braided. The one down to the wheel is ordinary.
Is your rubber line old or new? Old rubber hoses swell under pressure and limit the maximum pad pinch at the rotor.
How well are these bikes supposed to brake. My front brake is very lame when cold. As is heats up after a few brake ups it gets better. Even when warm i can pull the grip all the way to the handle and still barely get the front wheel to block. Is this normal or are my pads contaminated or?
Are these new pads or old? New pads take a while to fully seat and make full contact with the rotor.
If you have old pads that have EVER been contaminated with brake fluid, fork oil, or caliper housing grease, you will need new ones, or live with the weak brakes as they "lubricate" themselves.
With my 550s, the ones with old rubber lines, I cannot lock the front tire. The ones with SS braided lines, I can chirp the front tire with about 1/4 inch to go between the lever and grip. I can lock old hard tires. But, new soft rubber tires just sqwall and scare me.
Remember that Honda introduced the front disc brake with these old bikes. I believe they adjusted their sensitivity so that the riders of the older brakes won't grap a handfull in the corners and slide off the road on the side of the bike. You will NOT be able to one finger the SOHC4 brake lever.
The only other explanation for your lever/pressure issue is remaining air in the system. Bleed then as best up can and position the bike with the master relief port as near to the sky as you can manage. Allow to sit overnight. Next day open the top cap and watch that tiny hole as you slowly move the brake lever. Do you see any bubbles?
The other part of the front brake issue is that the caliber doesn't retract very well. I have dismantlet the caliber and I can have the pad falling out og the house by gravity. I can press the piston into the house with good use of my thumbs - and by this have brakfluid squirt out of the caliber house.
The test I use, is that with no seal in the caliper, the piston moves in and out of the caliper bore with gravity. So, should the brake pad.
Old seals may lose resiliency and fail to retract the pad. And, it their are lots of deep pits in the piston, this will prevent the puck seal from doing its job, as well.
As I see it there is only one possible cause og sticky brakes left - a clogged compensation port. I have tried to put a stiff nylonwire into the two holes in the reservoir. The one marked A i can get the nylon wire about 1/2" down into the hole. On the hole marked B I can get it 1/10" into the hole. Is the hole B clogged? If clogged i need to know the diameter of the often mentioned guitar string. When i bleed the brakes bubles only cmes out of hole A
If you can get bubbles out of the pressure relief hole in the master, it is not holding holding hydraulic pressure in the line. You can test for this by cracking open a hydraulic line. If this allows the piston to retract, then there is a master cyl problem. If not, the problem lies elsewhere.
I have seen rubber lines deteriorate internally and behave as one way valves. They would pass pressure/fluid to the caliper but not allow relief. Only way to find that was to crack the fittings at each end.
Cheers,
