Dual Circuit Brakes, Master Cylinder

[politeperson]

Ok I give up.
I have 4 outputs on the M/C and seemingly only three places to attach the pipes.
3x M10 and 1x M12.
One left wheel, one right wheel and the rear brake junction.
Where do the brake pipes go from the master cylinder any one please?

 

[petak]

My F4 has two lines that goes to the rear brake compensator








That could be issue with yours braking system

 

[jcarruthers2]

Hi
Some R4 master cylinders are three pipe outlet and some are four pipe outlet at the master cylinder end. If you have three pipes on your R4, the master cylinder in the image is not the correct one for your R4.

3 pipes = left front, right front and both rears

4 pipes = left front, right front, left rear and right rear.

 

[politeperson]

Thank Guys, that make sense.
It just make me wonder why I have 3x M10 fittings and 1x M12 fitting on the M/C?

 

[angel]

On cars with two rear brake pipes, one has an M12 union nut, presumably for not to be assembled incorrectly.
You can plug this M12 outlet and use the three remaining outlets for your existing brake pipes.

 

[politeperson]

OK, Thankyou.
So the answer is, Plug the M12 outlet.
Use one M10 for the rear brakes compensator.
Use the other two M10 outlets for each front wheel.
Makes sense.

 

[petak]

Angel.
Can same thing be done on my F4?
In that case i can use rear conpenastor from GTL. With only one input line.

 

[angel]

Both 4-outlet and 3-outlet master cylinder brake systems on the Renault 4 are split systems - one circuit operates the front brakes, the other the rear ones. Difference lies in the method used for failure warning: four outlet master cylinders have the PDI (pressure drop indicator) warning, that is, a piston between two pairs of fluid outlets moving when fluid pressure on one circuit drops (=failure), closing an electrical contact. Three outlet master cylinders got rid of the often troublesome hydraulic failure warning system, having a simple float in the reservoir cap that senses low fluid level.
So it should not be an issue functionality- and safety- wise fitting the four outlet master cylinder on the three outlet system, provided that front brake pipes are fitted on the same side of the PDI unit (both front or both rear outlets). I have successfully done the opposite in the past, I fitted a three outlet master cylinder on a 4-outlet system.
Two more notes: 4 outlet master cylinders have a bleed nipple at the PDI unit, this must be bled after all four wheels have been done.
Four outlet master cylinders are usually (but not always) supplied in 20,64mm inner diameter, while three outlet ones are 19,05 inner dia. Depending on your former fitment, you may end up with slightly less braking power or slightly longer pedal travel.