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Brake bleeding problems

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Brake bleeding problems

Postby Mayhem » Fri 7th Sep 2018, 05:37pm

Hi all
I've recently replaced the entire braking system with new pipes and wheel cylinders and bought a repair kit for the dual system brake master cylinder which I've fitted. There are no leaks anywhere but when I try to bleed the system all I get is a spongy pedal that hits the floor when pressed. I've undone the lower 1/2" pipe connector on the master cylinder and fluid pumps out ok. But when I do the same on the top one no fluid comes out. Any ideas? It's a non servo mini if that helps.

Thanks
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Re: Brake bleeding problems

Postby Zippyrude » Fri 7th Sep 2018, 07:10pm

did you follow the correct bleeding sequence?
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Re: Brake bleeding problems

Postby Mayhem » Fri 7th Sep 2018, 08:52pm

Yes but still no joy. There is nothing happening and brake fluid reservoir not going down whatsoever when the pedal is pressed no matter how many times I try.

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Re: Brake bleeding problems

Postby asahartz » Sat 8th Sep 2018, 11:13am

You've pretty much answered this yourself by saying no fluid comes out from the top union of your master cylinder. Something is wrong there. As you have fitted a repair kit, I can only guess that you have either done something wrong or missed something during this process.

Unpleasant as the job may be, I'd say the master cylinder needs to come off again for a strip down and recheck.
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Re: Brake bleeding problems

Postby Mayhem » Sat 8th Sep 2018, 01:07pm

Thanks for the replies. I think I will remove the master cylinder again and get another kit and try again and see what happens. Ive looked in the Haynes manual as a guide but it's not very helpful. When I stripped the cylinder down I just copied how it was before stripping when putting back together. Out of curiousity how would I know if the valve bias/compensator is faulty?

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Re: Brake bleeding problems

Postby Mayhem » Sun 9th Sep 2018, 06:20pm

All sorted now. Was a simple case of air trapped in the master cylinder which I did a bench bleed to solve it.
Thanks for your help guys.
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Re: Brake bleeding problems

Postby Nozzle » Mon 15th Oct 2018, 09:35pm

Nice work, glad it is solved.

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