Front brake on my 1979 Honda CB550 Four K

[SASCOT]

Hi ,I have just overhauled my master cylinder with a new plunger seals etc.. I have tried to bleed the brake but I'm still getting a very spongy feel and too much travel on the brake lever,has anyone any suggestions for me.
                               Thanks SASCOT

[Searchguru]

SASCOT,
I have had the same symptoms when replacing brake/clutch master and slave cylinders in the past. It is air in the system, pure and simple. To solve this very problem I went to a branch of Lloyds chemists and purchased the biggest syringe they could find. I managed to find some clear tubing which fitted both the nozzle of the syringe and the bleed nipple of the clutch slave cylinder that I was trying to bleed. You need multiple hands or a lot of patience but basically fill the syringe and tubing with brake fluid then attach it to the bleed nipple and open in by half or one turn (as you would for bleeding it conventionally) then with the master cylinder top off carefully 'inject' your brake fluid with the syringe. There should be some back pressure in the syringe at this point. Then slowly pull the lever in and (hopefully) you should start getting bubbles coming into the master cylinder reservoir. Keep some pressure on the syringe and repeat the procedure. It can be slow and messy and can need a friend to help but by 'backwashing' the system you can sometimes clear the air blockage quicker than conventionally. Finish the procedure with a conventional bleed and you should be sorted. Some auto factors sell syringes for this very purpose, so I'm told, but as long as you explain to the chemist why you need it you won't get odd looks. Good luck. Tony B.

[SASCOT]

Thanks Tony I will give it a go and let you Know if i am successful.

                                                                charlie

[SASCOT]

Hi Tony, I done exactly as you told me but without success, I still had too much travel on the lever and the brake felt spongy yet I was certain I had bled them properly.
                   I have however found the problem. The spur on the brake lever that pushes the master cylinder plunger is quite badly worn ,so I tried putting a spacer in to see if it helped (5mm thick),re bled the system and hey presto good solid brakes.So could see if I can get a new lever and check how much longer it is or just leave the spacer in as I made it up specially and there is no chance it can fall out.
  My next mission is to get the bike to idle properly as I removed the carbs and cleaned them out but I am not sure where to start resetting them on the bike. I have the bike running but the idling seems very sensitive I dont really know what I'm doing,any suggestions

                                                                                   Charlie

[Searchguru]

Congratulations with the brakes. Have you got a Haynes manual for your bike because it will explain about the carbs? You'll need vacuum guages to set them up properly. The manual will help enormously but have a butchers at this which might help. It's by another guru. http://www.bikeguru.co.uk/carbs.html