7 replies to this topic

[Nickj270386]

Hi guys I have a 1983 Mayfair you can no longer get the relevant brake master cylinder for this age vehicle so you have to fit the gmc227 (yellow tag) this is not a problem but anybody no what I have to do with the wiring for the master top,apparently you have to modify the wiring
Has anybody done this and have some more info
Thanks in advance

[Spider]

Is this the Master Cylinder it was fitted with ?

https://www.minispar...quare-reservoir

 

[mbolt998]

I did it by modifying the wires going into the back of the switch as follows:

 

https://www.theminif...need/?p=3765405

 

Other solutions are possible. Also make sure that the bottom section of the new MC goes to the rear brakes and the top to the fronts. It won't affect ultimate braking performance but will give you a much more natural feeling pedal (mine was wrong for years after an ignorant garage blah blah long story).

[coopertaz]

I did it by modifying the wires going into the back of the switch as follows:

 

https://www.theminif...need/?p=3765405

 

Other solutions are possible. Also make sure that the bottom section of the new MC goes to the rear brakes and the top to the fronts. It won't affect ultimate braking performance but will give you a much more natural feeling pedal (mine was wrong for years after an ignorant garage blah blah long story).

ignorant main dealer changed mine years ago and locks up the rears.

[Nickj270386]

Is this the Master Cylinder it was fitted with ?

https://www.minispar...quare-reservoir

No not that one

[Spider]

 

Is this the Master Cylinder it was fitted with ?

https://www.minispar...quare-reservoir

No not that one

 

 

Can you post a photo of what you have ?

[Ethel]

The pressure failure sensors had continuity across both terminals* so pressing the brake warning switch showed the wiring was good.

 

The fluid level  float just makes the circuit if the float drops, hence the "dibber" sticking up through the lid that makes a better test than pressing the brake warning switch, that just tests the bulb when there's a float switch.

 

Join both wires at the master cylinder together & also connect them to one side of the float switch. Earth the other side.

 

* if there was a pressure failure the switch earthed itself via the master cylinder, lighting the bulb. The warning switch, also connected to earth when pressed.

[Nickj270386]

The pressure failure sensors had continuity across both terminals* so pressing the brake warning switch showed the wiring was good.

The fluid level float just makes the circuit if the float drops, hence the "dibber" sticking up through the lid that makes a better test than pressing the brake warning switch, that just tests the bulb when there's a float switch.

Join both wires at the master cylinder together & also connect them to one side of the float switch. Earth the other side.

* if there was a pressure failure the switch earthed itself via the master cylinder, lighting the bulb. The warning switch, also connected to earth when pressed.

That’s fantastic cheers mate