Disc brake bodge - ...
 

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[Closed] Disc brake bodge - Is this possible - will I (or rather my son) die

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My son has a bike with Giant MPH brakes but the rear brake lever no longer works, it's leaking through the lever it self.

He uses it more as a 'getting to his mates' bike now so would rather not spend £££ on a new set of brakes.

So to the question.

I have an old HS33 lever in the spares box. Could I use those?
I guess it comes down to hose diameter & the ammount of oil thrown by the lever.


 
Posted : 01/04/2014 7:42 am
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If the hose fits it will probably work just fine. The worst thing you may get is the lever stroke may be different than the other brake, but you can compensate for that to some extent with the lever adjustment screw.


 
Posted : 01/04/2014 7:47 am
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Don't the giants use Dot fluid and the hs33 use mineral oil? Probably not a good combo.


 
Posted : 01/04/2014 7:50 am
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It won't work.
As nickjb says, Giant used DOT fluid in those & Magura Mineral oil.
I'd say they're different ratios when it comes to the amount of fluid being pushed as well.
You'd be better off buying a cheapo used brake from the classifieds on here IMO.


 
Posted : 01/04/2014 8:00 am
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HS33's are a closed system, what are the MPH? most disc are open, and the 2 aren't compatible.

The fluid is another issue as DOT and mineral aren't mixable as noted above.

[url= http://www.support-english.magura.com/index.php?showtopic=1083 ]Magura's take on it[/url]


 
Posted : 01/04/2014 8:24 am
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basic low end deore's are so cheap and decent. I'd just replace


 
Posted : 01/04/2014 8:27 am
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The older MPH are a closed system, they only went to an open system later on when they swapped to mineral oil (essentially same brake as deore & tektro at the time)
I still wouldn't risk it though.


 
Posted : 01/04/2014 8:31 am
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thanks all.

botch aborted.

I knew about the fluid difference but reckoned a good flushing would be fine, but interesting what Magura say as per the seals.


 
Posted : 01/04/2014 9:22 am
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I've got a set of Quad Nano brakes going for cheap. They are missing one pad, and I couldn't find a supplier at the time (bought some Deores).
Turns out the pads are [url= https://www.google.co.uk/search?q=qdp32 ]quite easy to find[/url].

They're similar in stopping feel to Deores, maybe not quite as sharp. Looking for ~£20 + postage for the pair.


 
Posted : 01/04/2014 9:37 am
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eltonerino,

1) what model are they
2) & what sort of condition & age are they in
3) what are the 3 pads like

Cheers,
Bill


 
Posted : 01/04/2014 1:26 pm
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Hi Bill,

They are "Quad QHD-7 Nano" and about 2 years old (but have been off the bike since November). They are in decent enough condition (see photo), with a few scratches on the levers and one of the callipers, but nothing getting close to worn out. There is still plenty of life left in the three pads. I've also got a bleed kit that fits them if you want that too.

[img] [/img]
I think I've shown the worst of the damage. It doesn't look as noticeable in real life, especially when they are on the bike.

[img] [/img]


 
Posted : 01/04/2014 1:58 pm
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HS33's are a closed system, what are the MPH? most disc are open, and the 2 aren't compatible

Are you sure - I wouldn't have thought the caliper cared whether the lever was open or closed.....?


 
Posted : 01/04/2014 1:58 pm
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closed systems have a sprung return for the piston. It doesn't just rely on seal flex. So a closed claiper on a open lever will just have the piston fully retracting everytime.


 
Posted : 01/04/2014 2:14 pm
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eltonerino,

Thanks but I'll pass.
Quite possibly a bargain I admit, but I'd rather buy some brakes I have heard of & not add yet another make of brakes to my disparate collection.


 
Posted : 02/04/2014 7:42 am
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🙂 NP, I understand. I've got Deores now, I can pick up spares pretty much anywhere.


 
Posted : 02/04/2014 11:45 am
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You can often pick up a pair of MPHs on eBay for <£40. And they're new, used ones come up for almost nothing


 
Posted : 02/04/2014 12:49 pm

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