Jump to content


Photo
- - - - -

Rear Wheel Cylinder Issue Question / 7.5'' Brakes


  • Please log in to reply
18 replies to this topic

#16 Ethel

Ethel

    ..is NOT a girl!

  • TMF Team
  • PipPipPipPipPipPipPipPipPipPipPip
  • 25,379 posts
  • Local Club: none

Posted 23 February 2018 - 02:38 PM

There were some cars without a limiter, but only as part of the diagonal split dual circuit system. If there's a Tee on the rear subframe yours wont be one. It would fit with a FAM7821 limiter fitted up front and, as I don't know Oz Minis, it'd be possible to use the 1/2" bore rear cylinders from the diagonal split set up in a front/rear configuration instead.



#17 Spider

Spider

    Moved Into The Garage

  • Admin
  • PipPipPipPipPipPipPipPipPipPipPip
  • 13,844 posts
  • Location: NSW
  • Local Club: South Australian Moke Club

Posted 23 February 2018 - 05:38 PM

Hi Timmy,

 

I hear you but my car has only a simple T piece. (Due to my work in a previous life I know a T piece when I see one). Why I have only a T piece I have no idea. I'll research it here and try to find out why... Maybe a previous owner(s) installed it? The car is 50 years old.. The odd thing is, looking at it and the design (brass, looks 50 years old..), it looks like an original bit of equipment made to fit where it is. I don't know...

Having said that, the brakes work very well as they are. A mystery...  

 

Mikal,

 

All Ozzie built Minis, Vans & Mokes included, had a pressure shut off valve mounted to the font rail of the rear subframe, up to about 1976 when they introduced the Tandem Master Cylinder. If you only have a Tee piece here, then someone has fitted that or most likely swapped the rear subframe from a later car.

 

The 5/8" Bore Wheel Cylinders are the right ones to use. If it had drums up front previously, then it's highly likely the cylinders you have a 3/4" and they will lock for sure.

 

You can run without the pressure shut off valve, however you'll need to go to 1/2" Wheel Cylinders. Be aware though that you'll have markedly reduced rear braking. If at some point you need to take it for a RWC, there's a good chance it will fail that with the 1/2" cylinders, they just pass (and sometimes with the aid of a sympathetic inspector) with the 5/8" cylinders.

 

Go see Brian at Link or hound John at Mini King for a Pressure Shut off valve. There were about 7 different types, but as the one needed for the Disc Brake set up has the highest pressure, any you find will work. If you wanted to get keen, they only difference between all of them is the internal spring to give different shut off pressures. 450 PSI is the one to aim for, but any will be better than none.



#18 rider4life

rider4life

    Passed Test

  • Noobies
  • PipPip
  • 34 posts
  • Location: London

Posted 25 February 2018 - 09:53 PM

I'll post up pictures of my whole brake setup tomorrow, See what you think



#19 Sprocket

Sprocket

    Great on Injection faults

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 7,266 posts
  • Location: Warrington
  • Local Club: Manchester Minis

Posted 26 February 2018 - 12:23 AM

According to Minispares technical chart, all Mini's 1978 onwards were front rear split, with GWC1102 3/4" rear cylinders and FAM7821 pressure reducing valve on the bulkhead in the engine bay. Master cylinder should be the tandem type, doesn't really matter which as there is only really one now anyway, which is the 'yellow tag' GMC227. There was a simple 'T' on the rear subframe. The braking system hydraulics didn't change much (drums and discs aside) from then right up to 2000

If you don't have the FAM7821 valve on the bulkhead, this will be your problem.






1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users