Joined: Mar 2015 Posts: 5,193 Threads: 223
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Location: Scotchland
Does anyone know if an alternative to the normal Morris Minor (early aluminium and later cast iron) hydraulic cylinders are commonly used on A7s at all. The Master cylinder is from a Triumph Vitesse.
I will post photos when I can get nearer to the car but interested to know if anyone can suggest another type commonly used please?
Joined: May 2018 Posts: 1,915 Threads: 102
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Location: Llandrindod Wells
Car type: 29 Special, 30 RK, 28 C Cab
Hi Ruairidh and David
Sorry Ruairidh can’t really help and whilst there is a danger of thread hijack I’d like to comment on David’s question.
One problem you will face with the hydraulic master cylinder is that where you attach the main push rod on the brake pedal will affect the leverage and amount the push rod can move in the cylinder. I found on a previous special that I couldn’t get enough throw to push sufficient fluid around the system. I started using an aftermarket Girling cylinder, 3/4” from memory, but went up to a 7/8” cylinder in order to get sufficient fluid movement.
Hope you get some answers Ruairidh.
Cheers
Howard
Joined: Mar 2015 Posts: 5,193 Threads: 223
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Location: Scotchland
A little more digging and it appears they are rear mini cylinders, all round, grafted to semi Girling backplates...
Joined: Aug 2017 Posts: 106 Threads: 6
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My special user Girling Standard 8 cylinders and a 3/4 Girling master cylinder. The Triumph Herald cylinders are the same on the back I think, but the fronts are different
Joined: Feb 2018 Posts: 367 Threads: 14
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Location: Western Brittany (France)
Hi Ruairidh and all,
For once maybe I'm able to give some useful advice here. That will be a first!
I did three times a cable to hydraulic conversion on cars so I've some experience. At least I can tell which mistakes I made.
The choice of master cylinder is very good because those Girling exist in different bores so you can later change if the first choice happen to be wrong.
Then as was emphasized above two things are very important:
The lever effect ie pedal axle to foot versus pedal axle to master cylinder push arm. Better to be able to modify that later if needed.
The rigidity of all the apparatus is incredibly difficult to achieve. Is as better to have the pedal and the master cylinder bolted on the same solid metal contraption and the whole rigidly fixed on the chassis. We are speaking hundreds of kilos of force applied here.
Sorry if my english is not really up to the task!
Joined: Aug 2017 Posts: 216 Threads: 7
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Location: Edinburgh/Lothians
Car type: Seven Special
Hi Rauiridh,
Mini ones were 5/8" dia. Austin A40 Mk2 and MG Midget ones all look very similar but some went up to 3/4". Austin/Morris/BMC used very similar ones with differing piston dia. on rears so all may fit but hydraulic gain will obviously differ.
