Dual circuit master cylinder

[Ausstromer]

Hi all, just a quick question.   I'm converting my car top front discs,  similar to the exporer setup,  just using locally available parts,  Australian Falcon twin piston calipers.  Standard rear drums.   May change later to a jeep diff / rear drums.

 

I'm retaining the standard brake pedal.   I can't use the eci setup due to my car being right hand drive.   I was going to gut the standard m/c and mount the new 1" master cylinder behind the original. 

 

Has anyone doing this had an issue with pedal travel?  The standard pedal doesn't have a lot of stroke at the m/c, certainly not as much at the m/c donor vehicle.   I'm not sure if it's going to be sufficient to operate the brakes properly.  I noticed eci's setup extends the pedal to increase m/c stroke.

 

 

[Robert Horne]

On my 48 Dodge, I used a Ford MC running a rod through the original MC, worked good.

[maok]

You could use a larger bore master cylinder to allow for a shorter pedal travel.

[Ausstromer]

16 hours ago, maok said:

You could use a larger bore master cylinder to allow for a shorter pedal travel.

Robert, I was effectively copying your idea, other then using remote reservoirs.

 

Maok, I could be overthinking this.  I was aware of what you said, however is there an issue if the pedal doesn't operate through the full strike of the master cylinder.  Obviously if sized correctly it's not going have the m/C bottoming out unless there is a major brake failure.

[Plymouthy Adams]

Quote

16 hours ago, maok said:

You could use a larger bore master cylinder to allow for a shorter pedal travel.

 

 

if you were to increase you bore a bit oversize you run the risk of a very hard pedal pressure on your part as you brake...the smaller piston while is a decrease in volume, makes for more pressure to the cylinders with less effort on your part....just something to consider....it is a creature comfort issue at times...

[maok]

5 hours ago, Plymouthy Adams said:

 

if you were to increase you bore a bit oversize you run the risk of a very hard pedal pressure on your part as you brake...the smaller piston while is a decrease in volume, makes for more pressure to the cylinders with less effort on your part....just something to consider....it is a creature comfort issue at times...

 

Check the size  difference in your brake lines to the donor car MC? Is the original MC smaller or larger bore size?

MC bore to brake line sizes needs to be considered to determine the hardness of the pedal feel.

[Ausstromer]

Thanks,  haven't got as far as new lines yet.   The whole car will get new brake lines to suit with the remote brake booster.  It was more just a concern over the limited throw / stroke of the lever below the floor for the operation of the m/c.  Although i think i may have a plan to increase the stroke which eliminates all these questions.