Have overhauled the front master cylinder and fitted new piston etc, bled the system but no real pressure as the lever hits the grips? any advice

If you are loosing prime in the system but not loosing fluid my best guess would be the master cylinder.

Some brake systems have a pressure control valve usually soon after the master cylinder that cuts off the circuit with low or no pressure in the event of a leak or rupture of the line.
Trace the metal brake lines from the master cylinder down the chassis and you may find a small cylindrical valve that has 2 inlets from the M/C and 2 outlets leading front and rear. The method of centring the piston in this valve varies from one supplier to another but basically the good rear system has pushed the piston one way and cut off the front circuit. If you lightly release the pressure in the rear system, then try and bleed the front system it may push the piston back to centre. If it does, close the rear system and then front and see if you have any front circuit pressure.
This is only a guess at your problem but remember, brakes are your life, don't be embarrassed to get help or get a manual.

The brake hose is clogged. When under pressure from applying breaks, the piston is forced tight to the rotor. When released the fluid will not return through the hose because there is no real pressure. Replace the hose.
murf427

Hi, this will be air in the system which needs to be bled out, after a rebuild the air can become traped.the first thing you need to do is make sure you remove the air from the master cylinder end, tou will need a brake hose clamp, if you dont have one you can use 2 small sockets between a pair of grip jaws, clamp the hose as close as you can to the mastercylinder, now pull the lever and feel for pressure, next undo both bleed nipples with a pipe fitted to catch the fluid, with the nipples open slightly release the pressure on the grips pull in the lever all the way, but dont release the lever until you have re applied the pressure to the grips, this will ensure you dont let air back into the mastercylinder, so its release grips pull lever in , reclamp grips release lever, repeat this a couple of times then leave clamped, now when you pull lever it should be solid, if so you have removed all the air from the master cylinder, making sure you keep the fluid level toped up at all times, you can now continue this process closing off one nipple and forcing out the air, repeate on other side till all air is removed, you may then wish to bleed as usual to finnish off, this task should only be used if the machine still has the original rubber brake lines fitted, good luck

http://www.bareasschoppers.com/clutchbleed

This is for an 1800 vtx, but hope it helps

Loosen the bolt going into the master cylinder just enough to allow brake fluid to come out when you pump the lever. Retighten the master cylinder bolt. Once you have the master cylinder bled the rest of the system will be easy.

TAKEN A CHANCE OVERHAULING MASTER CYLINDER.BEST TO TRADE OLD UNIT IN FOR A NEW ONE OR REBUILT ONE.SINCE YOU HAVE ABS BRAKE SYSTEM YOU WILL HAVE TO HAVE A SCANNER AND BRAKES HAS TO BE BLED USING PRESSURE BLEEDER.

You may have a leak in the booster or master cylinder. You can put a pressure tester on the system to test for leaks. It does sound like you have an air leak.
You can try to bleed the master cylinder, then slave cylinder, then brake lines.

Possibly 2 problems m8.
If the brake-lever travel has increased then it either wasn't bled up properly or it's allowing air past the seals in the master-cylinder.
Try tying the lever back to the bar overnight to bring any air in the system up to the top (resevoir) and see if the brakes stay good, if not they'll need bleeding again.
Check for any leaks around all the banjo connections, up at the bars and down at the calipers, plus have a close inspection of the master-cylinder piston area for leaks.
The juddering might be down to a warped disc or two, get the front wheel off the ground and spin the wheel to check for this visually or with a stick and pointer.

Hi
I also have this on my 2003 SV1000S and have now overhauled the entire system changed all the caliper seals and fitted a new master cylinder kit and used new silkolene Dot 4 fluid. The brakes are very powerful now with no spongy feel on the lever but still to much movement to the bite point. Also the lever is too near the grip even on the max adjustment.
As everything is now perfect the only solution now is to pack the lever (3-positions)to reduce the movement and move it back from the grip when brakes applied (dont forget to pack the brake light switch). Care to be taken that there is enough retraction of the caliper pistons to allow the disc to run free and that the master piston seal retracts enough to allow the fluid to be pushed back into the reservoir. A very thin shim required.
Regards Bobdabiker