Rear brake master cylinder suggestions pls.

[J-max]

In my other thread on m/c size I ended up reusing the Fiat uno/panda 3/4" (19mm) single line clutch m/c that was orig. installed (but made a better job of it). I've been using it a while now & while it's working better than before, I can't get enough pressure through it get near locking even at full travel 2 -3". It's enough to get it through the MOT but doesn't feel nice at all. So I'm investigating a replacement.

Atm I'm needing advice on the following:

1) Would increasing bore to 7/8" (22mm) single line give me a stiffer pedal / more force?

I'm thinking yes, as there'll be more fluid going into the same pipework.

2) Or, would switching to a proper brake m/c in 3/4" (19mm) but with dual output line (one to ea side) give me a stiffer pedal / more force?

I'm thinking no, as I'll be doubling up the pipe work but also yes, as each line would then only be operating one set of calipers (& not both from single line as at present).

3) Looking for any suggestions as to actual examples of either 1) or 2) that might fit in that location (as there's nowhere else for it to go). See pic. Would be operating drum to disc conversion, single discs on English axel (MK1 ford escort).

 

[Marc H]

If you go bigger you may get a stiffer pedal but you will have to give even more pedal pressure than you are now.The smaller the dia. of your master the more hydraulic multiplication you have.You may want to try a 5/8 dia. master or look into ways to increase the mechanical leverage put on the master.Longer brake pedal would do that.Either will result in more pedal travel.

 

[J-max]

If you go bigger you may get a stiffer pedal but you will have to give even more pedal pressure than you are now.The smaller the dia. of your master the more hydraulic multiplication you have.You may want to try a 5/8 dia. master or look into ways to increase the mechanical leverage put on the master.Longer brake pedal would do that.Either will result in more pedal travel.

Looking like bigger is what I need then. Pedal pressure atm isn't particularly high & travel is already quite long to get results. I did try the 1/2" OEM but this failed to operate them at all.

 

[Horsehammerr]

No Rear Brakes

Looking like bigger is what I need then. Pedal pressure atm isn't particularly high & travel is already quite long to get results. I did try the 1/2" OEM but this failed to operate them at all.

I just installed a New OEM Rear Master Cylinder on my IMC Trike Conversion . I have WILWOOD Disc Brakes on the rear . I have gone through Vacuum , Pumping , Forward and Reverse Bleeding . I am LOST , as to how to get Brake Pressure to this New Master Cylinder . HELP !

 

[TwistedKarma]

Generally, if the back disc are for that rear, wheel cyls are matching

You want the master cyl to travel only half of its total travel to stop , lockup the wheels, because, the rest of the travel, is a safety margin.

I think this is what i remember, from calls to willwood.

After that, its down to length of pedal from pivot, to plunger to your foot area., enough leverage to apply,

Willwood, was very helpfull with my build, but i bought 2 different pedals to make it work

Remember, safety margin is key. Its trial and error,

Your travel was pedal, or mc shaft travel?