Rear upright assembly

[voucht]

Oscar,
I have the same uprights as you, but with drum brakes. I guess for disc brakes, they should be the other way around.
For drums : the two top holes of RU8 are towards the front of the car if it makes sense. On this picture: the left side of my chassis (driver side for me but passenger side for you )

IMG_2812_1.JPG

Hope this will help.

[alga]

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.

[Oscar]

Now I'm even more confused!

Two top holes towards the front is how i'd guessed the uprights would be for discs. Need someone who's built a disc rear with these. Maybe Talon will be able set this to rest...

[voucht]

Originally Posted by alga

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

[robo]

[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

[voucht]

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

[robo]

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 .

Bob

[voucht]

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