randall977 Sep 24, 2013 8:35 am
Subject: Dual system brakes...

I'm replacing all of the brake pipes on the Rapide in Cunifer pipework and I realised that the duel system (as setup on the Rapide) has no safety benefit if one system looses pressure...

The brake pedal is connected to the two master cylinders with a bar which is pivoted in the middle (see photo below; taken a while ago) . If one system looses pressure the bar pivots and therefore does not allow you to operate the good side effectively - the pedal hits the floor.

I found this to be the case when I bled one system and tried the brakes.

Just an observation!

ray sherratt Sep 24, 2013 7:41 pm
Subject: Re: Dual system brakes...

Hi Christian,
Make shaw the correct size cylinders are fitted and the rightway round. On competition setups the bar is adjustable
by means of threaded bar and yokes. On your system the bar
should lock against the yoke, the master cyl is threaded
into. Meaning the pedal should push the good system to brake
the car.
Ray.

randall977 Sep 24, 2013 11:33 pm
Subject: Re: Dual system brakes...

Thanks Ray, I think I know the master cylinders you mean - with threaded rods. What happens if one side requires more pressure than the other - such as the rear (as it has a longer run of pipe)? If the rods are locked to the yolk won't it bias one side etc?

ray sherratt Sep 25, 2013 7:17 pm
Subject: Re: Dual system brakes...

Hi Christian.
I assume the system on your car is a front\rear split, and not
split diagonal front\rear. Anyway the lenght of pipe makes no
differance on presure that the front or rear cyls see on entry
into that cylinder. It would be nice to see a close up of the
bias bar assembly if you could post it on the site.
Ray.

ray sherratt Sep 25, 2013 7:34 pm
Subject: Re: Dual system brakes...

Hi Christian
On taking a 400% increase in viewing the picture I see that your
dias is prodution fixed. the bar between the cyls is set to give
the correct presure front\rear. If the clevis pin is in the centre
of the yokes and the cyls are the same size ,then the presure
produced will be the same from each cylender.
Ray.
Ps. It would be nice to see some close pics of the setup.

randall977 Sep 25, 2013 10:38 pm
Subject: Re: Dual system brakes...

Hi Ray, you know your stuff! I will get a close up pic soon...