Brake

[DPC]

We have a Robin Hood 2B Dona 1985 Sierra which we are trying to build.  We have 2 problems the master cylinder is US and the brake servo is too big and hits are 4 into one exhaust

Fist questing do I need a brake servo????

Second what car master cylinder do I look for

Got to scrap yard this weekend what do I look for. 

[Sparepart]

This topic has come up before. I did a simple search for "Brake" and "Servo" and near the top of the hits was the exact same question.

https://www.rhocar.org/index.php?/forums/topic/48518-brake-servo-touching-manifold

Browsing the others it looks like there have been several solutions, just fit a Ford Ka master cylinder, use the Sierra master without a servo. Have a look there is a wealth of information in past topics.

 

[DPC]

Thanks, I will buy a new KA master cylinder.

[rthomas69]

I've fitted a Focus master cylinder without the servo. One of the reasons I went with this one is because I've fitted Focus rear brakes (discs) so the theory was the brake balance from this servo should be right.

[DPC]

We have purchased Ka master cylinder with out servo

Please see photo I presume pipes nearest the steering wheel go to the rear wheels and the ones nearest the radiator go to the front wheels.   Also do the front wheel brake pipes need to both be the same length.

[IanS]

Yes 2 front for front brakes, length does not matter as whilst braking there is little fluid flow so presures the same at all ports.

The singleton goes to rear brakes. This way a fault leaves you with either both front brakes or (worse) with both rear brakes.

[DPC]

There is actually 2 pipes for the rear as well on this Ka block.

[IanS]

Come to think of it the Ka did a diagonal split. One front and the opposite rear on each circuit which would explain 4 ports on the master cylinder.

It is up to you if you do this rather than the more traditional front / rear split.