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  #11  
Old 7th January 2013, 06:21 AM
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voucht voucht is offline
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Quote:
Originally Posted by alga View Post
I'm thinking, what effect would such orientation have when bleeding the cylinders? A pocket of air against the piston might be a nightmare to get out.
The bleeder is of course on top position on the wheel cylinder and is at the highest point of it. So it is theoretically even easier to bleed than a flat mounted wheel cylinder.

http://www.haynes.co.uk/forums/attac...1&d=1357384227

Oscar, Phil (Talon) told in the first place to put them the other way around for drum brake, but if I do so, the handbrake cable sleeve is too short to go to the back of the drum flange. So I had to put them this way which I thought was the normal way for drums. But perhaps it isn't, and the disc set-up is "top holes towards the front" as well. Sorry to get you even more confused
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  #12  
Old 7th January 2013, 06:32 AM
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[quote=voucht;87700]The bleeder is of course on top position on the wheel cylinder and is at the highest point of it. So it is theoretically even easier to bleed than a flat mounted wheel cylinder.

Alga is corrrect on this. Both of the drillings into the brake slave are angled towards the center of the unit. If the piston is not pushed fully back when the brakes are bleed the piston looking skyward will have air trapped under it.

Bob
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  #13  
Old 7th January 2013, 06:44 AM
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Bob, I don't know if you had a look at the picture I put a link to, but to me it looks pretty obvious that the air can only go up to the bleeder, even more if as you say, "the drillings into the brake slave are angled towards the center of the unit", no? With this set-up, "the centre of the unit" is still lower than the bleeder and the bleeder seat. Or I don't understand anything any more...
Well, I haven't tried to bleed the brake so far, so I can't say for sure, but I don't see where a bubble can be trapped inside the cylinder with this set-up
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  #14  
Old 7th January 2013, 10:19 AM
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Yes I did see the link. Think of it like this, the bleed screw and the feed pipe are both channeled to the center of the cylinder, the bleeder can only let air out up to and below that point. Once the brake shoes and drums are on the upper piston will push out and that will be the pocket of air that that cannot be bled off as the bleed nipple is below the pocket of air.. I am crap at drawings so I cant do you a diagram .

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  #15  
Old 7th January 2013, 12:23 PM
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OK ok, I totally get your point now, sorry I didn't get it the first time
Yes you are right, this might be a problem.

But note that on the Sierra, wheel cylinders are not flat either, but they lean backward too, not as much as these 30, but they do (I would say about 15).

The other point is, when you bleed, the pistons don't move and stay in the "closed" position (if I can say so). So if in this position, the bottom of the top piston is lower than the bleeder hole (depend on the piston's thickness, I think it is but it has to be checked), the problem you describe should not occur.

Or at least that is my hope

We'll see when I bleed my brakes
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  #16  
Old 7th January 2013, 12:55 PM
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It might be best to centralise and clamp both pistons shut to bleed the rears then fit the shoes+drums after. Just thoughts.

Bob
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  #17  
Old 7th January 2013, 01:53 PM
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Hang on, am I the only person on here using discs?!?!

Just had a look through my dismanling photos and can say for certain that the rear disc calipers sit practically on top of the disc, slightly back.

This leads me to conclude that the top holes of the rear uprights must be forwards!

Anyone disagree?
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  #18  
Old 7th January 2013, 06:39 PM
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Now looked at Janne's and superseven's builds, both use discs and have the calipers mounted on the rear.

This talleys with what Talon has said and indicates the top holes are indeed forwards. This also keeps the bleed tube at the top.
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  #19  
Old 7th January 2013, 06:45 PM
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Sierra rear calipers original position:


And some MK Indy caliper position (upside down) - similar to Haynes Roadster I think:



Hope this will be helpful for you...
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  #20  
Old 7th January 2013, 07:13 PM
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Thats looks almost exactly as I thought. Cheers Loony

And yes, the mk Indy ones are very similair to the sierra ones, right down to the Ford marking!
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