Hydraulic front brake

Information relating to the Matchless G12 or AJS Model 31 650cc twin
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tracyawuk
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Location: Devon UK

Hydraulic front brake

Post by tracyawuk »

Hi I have a hydraulic brake conversion on the front. I’ve just had to take the drum apart to free off the brake as it was binding and reassembled. I now have an issue where the brake seems to ‘back off’ when riding such that you have to pump The brake sharpish to get some stopping power. I’ve took the drum apart again and can’t seem to see anyway of setting the brake shoes or a ‘ratchet’ type assembly to keep the brake shoes against the drum. I believe it is a Malcolm Saggers conversion. Does anyone have experience of the set up please?
SPRIDDLER
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Re: Hydraulic front brake

Post by SPRIDDLER »

If it is the Malcolm Saggers (RIP) TLS conversion it uses Mini wheel cylinders which I believe is like all hydraulic systems in that shoe adjustment it relies upon the 'relaxing' of the shoes to return a small amount of fluid to the master cylinder reservoir to maintain brake shoe adjustment.
There's an article on the Malcolm Saggers conversion in the 'Technical Articles' section of the club website where it's mentioned that after the usual bleeding a hypodeemic nerdle had to be used to get the last bit of air out of the system.
See the article here:

https://www.jampot.com/article_read.asp?id=410
'There is a tide in the affairs of men
Which taken at the flood............'
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griffin
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Re: Hydraulic front brake

Post by griffin »

Troy does the master cylinder have a adjusting screw in the lever ? Mine does and I wind this in till the shoes start to touch then back off slightly to ensure they are free.
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Duncan
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Re: Hydraulic front brake

Post by Duncan »

If you search the forum on hydraulic 42 pages come up, then search on brake whittles it down to 17, this discussion may have some gems in it: viewtopic.php?p=38593#p38593
56G80S
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Re: Hydraulic front brake

Post by 56G80S »

This may not apply but the Yamaha I had was known to be problematic for bleeding the brakes. Reverse bleeding can solve this, it did for me, I wonder if that's what Sprid is referring to, see this:

https://duckduckgo.com/?q=reverse+bleed ... iWnc4fNGCo

Don't forget to use fresh brake fluid, don't shake it, let it stand at least overnight and leave the system overnight if it's spongy and do it again another day.

Johnny B
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les ward
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Re: Hydraulic front brake

Post by les ward »

I had a similar problem on my Commando. I did the reverse bleeding, as mentioned above, but still had the problem. I used cable ties to hold the brake on hard and left it overnight. That worked for me.
tracyawuk
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Location: Devon UK

Re: Hydraulic front brake

Post by tracyawuk »

Thanks all. I'll try bleeding it again and go from there.
mdt-son
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Re: Hydraulic front brake

Post by mdt-son »

Agreed, entrapped air seems to be your problem. Bleeding the system can be tricky with small diameter brake lines. Using compressed air may help, if you are able to seal off the master cylinder. Internet is your friend!

- Knut
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