172 -> 172 Cup brake conversion

[harboged]

Hi,

Is there a detailed thread covering the conversion from the 172/182 brake system to the one of the 172 Cup?

I'm about to to this on my 172 by installing the Cup master cylinder and by-passing the ABS-unit and I wonder what the diameter of the brake lines that go to the front calipers, number 1 and 6 in the attached photo, is? Since the adapters are M12 instead of M10, as for the original master cylinder, I assume the diameter should be larger than for the existing lines.

However, if hose 11 in the photo is the same for the 172 and the 172 Cup, then the diameter of the lines mentioned above is irrelevant, or...?

What do people do with the lines going to the rear brakes? Do joiners 13 exist on the non Cup-version too? In that case I assume making two new lines from the M10 outlets of the master cylinder leading to the joiners is the easiest thing to do?

And finally, the brake compensator. What do I do with it?

Thanks

 

[Fellsy]

How did you get on with this mate.
Doing the exact thing as you so would be good to know

Hi,

Is there a detailed thread covering the conversion from the 172/182 brake system to the one of the 172 Cup?

I'm about to to this on my 172 by installing the Cup master cylinder and by-passing the ABS-unit and I wonder what the diameter of the brake lines that go to the front calipers, number 1 and 6 in the attached photo, is? Since the adapters are M12 instead of M10, as for the original master cylinder, I assume the diameter should be larger than for the existing lines.

However, if hose 11 in the photo is the same for the 172 and the 172 Cup, then the diameter of the lines mentioned above is irrelevant, or...?

What do people do with the lines going to the rear brakes? Do joiners 13 exist on the non Cup-version too? In that case I assume making two new lines from the M10 outlets of the master cylinder leading to the joiners is the easiest thing to do?

And finally, the brake compensator. What do I do with it?

Thanks





View attachment 167861

 

[harboged]

How did you get on with this mate.
Doing the exact thing as you so would be good to know

It worked out fine.

1. You need to get the compensator off a Cup because the standard 172 doesn't have one. It can be attached to the existing bracket and the lever should not be connected to anything.

2. You can use the same brake line diameter for both the M10 and M12 outlets of the master cylinder. I used 3/16" lines.

3. I didn't bother to join the new lines with the existing going to the rear. Instead I made new lines going all the way from the master cylinder to the compensator in the rear.

 

[Fellsy]

So you used the 2x ports furthest from the servo as the fronts, these being the m12 ones

It worked out fine.

1. You need to get the compensator off a Cup because the standard 172 doesn't have one. It can be attached to the existing bracket and the lever should not be connected to anything.

2. You can use the same brake line diameter for both the M10 and M12 outlets of the master cylinder. I used 3/16" lines.

3. I didn't bother to join the new lines with the existing going to the rear. Instead I made new lines going all the way from the master cylinder to the compensator in the rear.

 

[harboged]

So you used the 2x ports furthest from the servo as the fronts?

Yes, exactly as shown in the attached picture in my first post.

 

[Fellsy]

Are those the 2x m12 unions?
I only ask as there seems to be people on here with different variations of ports on there cup cylinders

 

[Fellsy]

Yes, exactly as shown in the attached picture in my first post.

So the m12 unions? I only ask as people seem to have different variations of cup cylinders

 

[harboged]

Are those the 2x m12 unions?
I only ask as there seems to be people on here with different variations of ports on there cup cylinders

Yes, as I remember that was the M12 unions. OK, that's a bit odd with different Cup master cylinders. I have two and they look the same though.

 

[Fellsy]

I know it's strange. A guy said he had m10 and m12 unions on his master cylinder but were diagonal to eachother