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Brakes
Morton - 4/6/17 at 05:03 AM

Hi my tiger super six been stood for months been out today when I pressed the brakes the back wheels locked up and I had to take the wheels off to free them up did that all pistons cleaned wheels where free but every time I press the pedal the wheels lock up again and I have to release the bleed nipple and they free up any clues thanks.

britishtrident - 4/6/17 at 05:36 AM

Locked in hydraulic pressure, something is preventing the piston in the mastercylinder returning fully, if the master cylinder piston is not returning fully against the internal stop ring by 1mm it will prevent pressure venting back to the resevoir.-- very common problem with home builds you need to look very carefully at your pedal pushrod setup.

Morton - 4/6/17 at 05:48 AM

Is it possible the master cylinder needs changing

britishtrident - 4/6/17 at 07:49 AM

quote:
Originally posted by Morton
Is it possible the master cylinder needs changing



Unlikely probably just adjustment and fettling of the push rods, or cleaning the end bore of the cylinder or fitting a return spring to the pedal.

[Edited on 4/6/17 by britishtrident]

40inches - 4/6/17 at 08:37 AM

Check that you have free play in the pedal to master cylinder push rod, around 2-3mm is usually enough.

SPYDER - 4/6/17 at 07:58 PM

Is there a residual pressure valve in the rear piping? If it was failing/sticking could it cause your symptoms?

Mike Bentley - 5/6/17 at 06:27 AM

I agree its, its either the master cylinder or compensation valve holding the pressure .
If you have a rear brake compensation valve then try releasing slightly the input pipe and if the brakes are still stuck on then its the comp valve, if the brakes release then its the master cylinder end.

Morton - 5/6/17 at 06:25 PM

Thanks for all the posts guys sorted it was a stuck compensater valve cheers