Front brake caliper rebuild.

[Fazerider]

Deenybean: With the caliper off, pump the lever until all 4 cylinders are as full as you dare get them (checking the level in the master cylinder as you're doing this, no point in pumping more air in!). If you don't have any fancy tools to limit the movement of the pistons, offcuts of wood or even a pair of old brake pads will act as suitable spacers.
Now tap the caliper gently to try to dislodge any stubborn little bubbles of air up towards the bleed nipple, loosen the nipple until you get no more air out then tighten it back up.
The next stage involves pushing the pistons back in, a couple of small G-clamps helps here, and the idea is to force the fluid back up the brake lines carrying any bubbles that have got stuck in the lines up to the reservoir. Have the top of the reservoir on loosely while you're doing this, a brisk flow is what you're aiming for and you don't want it squirting over the paintwork. If it's a bike with twin discs,  turn the steering to the left to avoid getting air trapped in the assembly that splits the brake lines.
Mind the reservoir doesn't overflow as you shove the pistons back, let some more out of the bleed nipple if it's getting close to the top.
You might need to repeat the process for both sides, but it eventually gets the brakes good and firm.

[His Dudeness]

I have a similair problem to those mentioned here. I replaced the piston seals on the front caliper after the bike failed it's MOT. The MOT tester said the brakes were binding and suggested replacing the seals. After doing that I bled the brakes following the instructions in the Haynes manual, but the brakes still feel spongy and I can pull the brake lever right back to the handle bar. Does anyone have any ideas what I've done wrong or suggestions for what else I can try?

I also noticed that when operating the brake lever once, the pistons don't all move equally, the small piston on one side of the caliper and the large piston on the other side moved out while the other two pistons hardly moved at all. Cause for concern?

you can also try to bleed the brakes at the banjo bolts.

[Deefer666]

If the you have really stubborn calipers that refuse to bleed up either take the top off the reservoir and cable tie the lever back to the bar and leave over night.

or

remove the calipers and hang them so that they are above the master cylinder and then bleed them that way as the air bubbles will travel upwards naturally..... But this is normally a last resort.

[born to be mild]

You must have a lot of air in the system for the lever to go that far back, deenybean. are you sure that your master cylinder seals arent shot?

[deenybean]

Read all the coments from above, ref bleeding brakes... Changed seals, cleaned pistons,bleed the system,taped the calipers 2 get rid of stuburn trapped air bubbles, took calipers off & raised them above master cylinder & bleed them, but still have spungy brakes. now i have clamped brake lever open 2 leave over night, failing that. im going 2 scrap the f%$kin thing. well pissed off......

[sjdfzs]

born to be wild... just wondering what the street triple is like speedwise to the fazer?
sorry to go off topic.

i had the same problem with the brake and it was just the master cylinder

[born to be mild]

Sorry SJDFS, just spotted your question, the Speedie is probably a more involving ride than the Fazer and maybe a little faster, acedemic really, lots more torque , less gearchanging and a lovely engine note on the overrun. Having said that the Fazer is a far better all rounder and is easier to maintain so much so that the trumpet sits under a blanket in the garage and the Fazer is the bike that I use in the summer. If youre thinking of getting an older Hinckley
Triumph PM  me, mines not for sale but I can tell you a bit more in depth of what to watch out for.