Strange brakes

[shamm]

I have just got my HC1800 on the road and the brakes are 'strange'.

The first third of the pedal travel is very light with minimal braking, the rest of the travel is solid and works fine.

Brake efficiency of fine as just passed MOT.
The inital travel is the front brakes only working slightly.
Have checked the disks/pads.
Have bleed the system, new fluid.
Have checked the rear drums/shoes and adjusted the rear shoes.
Have checked servo push rod adjustment

Any idea's anyone?

[lambaj]

Still sounds like some air in there somewhere. I have often had to do multiple bleeds to get the last few bits of trapped air out of the calipers. Have you a friend who can help ? that way you can do a "pressure" bleed, ie load the brakes, then open the relevant nipple a small amount. Sometimes I've found this trick helps dislodge bubbles stuck in calipers etc.
Other than that, might still be some play in the rear shoes caused by an excentric drum pushing the shoes about, but this is hard to spot when adjusting unless you can get the shoes touching and then turn the wheel round to see if the brakes lock up or let go.
One other very slim thing, a broken spring in the master cylinder ?

Hope you find it
Cheers
Tony (HA21)

[hbpeter]

Is it a tandem master cylinder? I.E a split braking system. If so it could be just one half is working the other passing??
Peter

[shamm]

Thanks for the suggestions.

It is a split system but both systems must work as it just passed the MOT.

Could be an excentric drum problem as I have noticed the handbrake has gone out of adjustment again.
Problem seems to be located at the back anyway, will have to jack it up and look again.

I wonder if the adjusters themselves (Girling manual adjusters) can break and stop holding the adjustment.
Will have to inspect and have a good check on this also.

Steve.

[lambaj]

The adjusters are like a pyramid headed bolt that operated against two opposed "followers". As you rotate the adjuster, you should feel the required pressure increase then back off for each 1/4 of a turn. It is important to make sure you leave the adjuster so the pressure is at it lowest, ie the followers are resting on the flat part of the pyramid, else it is very easy for the adjustment to back its self off in use.
When the adjuster is 30 years old, full of *Bleep* and old grease this setting can be very hit and miss. You can remove and overhaul the adjusters very simply, and a small amount of grease in the right place will ensure accurate adjustment.

Or, you drums are warped, or you have a bent half shaft......

A carefull check should hopefully find the problem.

Good luck

Tony (HA21)

[shamm]

Just need it to not rain at the weekend then