Breaking News - My Breaks Dont Work

Discuss all things 1970 & later Airheads right here.
jackonz
Posts: 179
Joined: Sat Oct 30, 2021 5:29 pm

Re: Breaking News - My Breaks Dont Work

Post by jackonz »

Hi, I would be looking at the master cylinder, not sure what set up you have but first off do you have the under fuel tank unit, if so make sure that the correct clearance is set for the cable, if not what can happen is that the piston in the cylinder will not return fully to open the small hole in the master cylinder, if this happens the brakes will lock on, the same can happen if the return spring inside the master cylinder has corroded and breaks and therefore not opening the small hole allowing the break fluid to return thus locking on the brakes.

As for bleeding use a vacuum bleeder for the under tank unit, they are known d=for this bleeding issue to get it started, once you have got it primed bleed it as normal but have the back end of the master cylinder propped up to allow air to work its way up, then leave it for at least 24 hours and see if it improves, if not bleed again.
Phil J

Nelson NZ.
damienbove
Posts: 30
Joined: Mon Mar 27, 2023 3:06 pm

Re: Breaking News - My Breaks Dont Work

Post by damienbove »

thanks guys, (Seth Kurt Jackonz and Meilvile) a couple of things to try there. i will give both of those a go and report back, before i start buying new brake cables.
damienbove
Posts: 30
Joined: Mon Mar 27, 2023 3:06 pm

Re: Breaking News - My Breaks Dont Work

Post by damienbove »

Once again, thanks to the guys on this forum, lifting the back of the master cylinder released a sizable amout of air and resolved my issue, so thanks once again.
jackonz
Posts: 179
Joined: Sat Oct 30, 2021 5:29 pm

Re: Breaking News - My Breaks Dont Work

Post by jackonz »

damienbove wrote: Tue Jan 02, 2024 5:58 am Once again, thanks to the guys on this forum, lifting the back of the master cylinder released a sizable amout of air and resolved my issue, so thanks once again.
Hi, glad you found something but I would be concerned that it had that much air in the system to cause that problem, how did the air get in therein the first place? was the master cylinder low on fluid to cause this.
Phil J

Nelson NZ.
mkj
Posts: 43
Joined: Thu Jan 06, 2022 4:29 pm

Re: Breaking News - My Breaks Dont Work

Post by mkj »

To me sounds like an air leak, I replaced all the brakes lines on my twin ate brakes, I got the parts from the local auto shop ordinary copper brake pipe and I used the flexibles off an Audi 80 . I did find it difficult at first to bleed the system I found covering the port on the master cylinder with my finger and pumping the brake seemed the help bleed the master cylinder itself.
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