MGB BRAKE VALVE ?

[jjroth63]

Hi,

I have owned my 1966 B for two weeks, I am not a mechanic. I have never worked on cars. I am having fun driving the car, I have learned that sun screen lotion is important for anyone driving a convertible in the summer. I have also learned that my wife can spot a drop of oil before it hits the garage floor.

So the rumors of early MGBs constantly weeping fluids is a true statement for my car. I have a piece of cardboard under the car and it is saturated with fluid.

Today's question is, what is this?

Can the leak be stopped?

Why is there an electrical terminal in the center.

My car is probably a Frankenstein, so the parts might not be 1966 specific.

Any help would be appreciated.

Thanks,

John

 

[mezy]

The switch in the middle of the block with pipes is a pressure opperated brakelight switch, which judging by the pickled painwork around it has been leaking for some time, This needs replacing ASAP before you loose too much brake fluid and no Brakes
The switch fitted to the black cover with some pigeon poop type welding is someones Heath Robinsons attemp at making the brake light switch mechanicle because the hydraulic one has failed.

 

[jjroth63]

The switch in the middle of the block with pipes is a pressure opperated brakelight switch, which judging by the pickled painwork around it has been leaking for some time, This needs replacing ASAP before you loose too much brake fluid and no Brakes
The switch fitted to the black cover with some pigeon poop type welding is someones Heath Robinsons attemp at making the brake light switch mechanicle because the hydraulic one has failed.

Hi,
I appreciate your reply, but I am sorry, I do not understand what you are saying, I am new to these cars and not a mechanic. Maybe a different English

Are you saying the leaky thing is a brake light pressure switch. It has been leaking for a long time and it has damaged the paint. This leak could cause the brakes to fail if the brake fluid gets too low in the master cylinder?

The current brake light switch has been installed in an unsatisfactory manner, but it does work.

Please correct me if I have misinterpreted your comments.

Thank you for taking the time to help me.

John

 

[jjroth63]

Can the brake light pressure switch be removed since I am not using it? or does the brake fluid have to go through it to operate the barkes?

 

[mezy]

You are correct in your understanding.
Yes the switch can be removed, the brakes do not rely on the switch for them to work,
but if you remove it you will need to replace it with something, would be best to fit a new one rather than trying to get something else to fit in the hole it came from and make a satisfactory seal, that way you could use it for the brake lights and remove the other Ugly one.

 

[jjroth63]

You are correct in your understanding.
Yes the switch can be removed, the brakes do not rely on the switch for them to work,
but if you remove it you will need to replace it with something, would be best to fit a new one rather than trying to get something else to fit in the hole it came from and make a satisfactory seal, that way you could use it for the brake lights and remove the other Ugly one.

Are the replacements of good quality or do I need to try to find an original pressure switch?

 

[Mickey Richaud]

John -

Some confusion here. The brake light switch is the one on the black "doghouse" covering the master cylinder. The other switch is for the warning light on the dash. Both of which would be incorrect for your '66, as they weren't introduced until '68 (I think). The switch on the brass fitting isn't necessary. But you do need to address the leak around the brass fitting (called a PDWA - Pressure Differential Warning Actuator). The good news is that your car was apparently upgraded to the dual line braking system.

Have a look here: > MGB Brake Master Cylinder and Hydraulics | Moss Motors <

Mickey

 

[jjroth63]

John -

Some confusion here. The brake light switch is the one on the black "doghouse" covering the master cylinder. The other switch is for the warning light on the dash. Both of which would be incorrect for your '66, as they weren't introduced until '68 (I think). The switch on the brass fitting isn't necessary. But you do need to address the leak around the brass fitting (called a PDWA - Pressure Differential Warning Actuator). The good news is that your car was apparently upgraded to the dual line braking system.

Have a look here: > MGB Brake Master Cylinder and Hydraulics | Moss Motors <

Mickey

Mickey,

Like I said, I think I have a Frankenstein and I do not know to what extent. there is a parts car near me, it is supposed to be an unmolested (rusted frame, floors, etc.)1967 MGB barn find, I am hoping I can bring my car closer to a 1966 with its parts. I assume that 66 and 67 are the same cars and parts.

Where would the warning light be? I had a lens to the left of the ignition switch, see photo. Could that be for the warning light? There is no bulb or housing, but I do have a rat's nest of wires under the dash.

Is this the part?

I do appreciate the dual bowl master brake cylinder "upgrade".

Thanks for your help.

John

 

[Mickey Richaud]

The warning light for the '68 and later B's is located on the upper eft side of the dash, incorporated with a spring-loaded switch. Here's a picture: > MGB Brake check switch 69-75 - Northwest Import Parts <

Have no idea what the red light next to your ignition switch would be.

 

[Mickey Richaud]

And yes, '66 and '67 were quite similar.

 

[jjroth63]

The warning light for the '68 and later B's is located on the upper eft side of the dash, incorporated with a spring-loaded switch. Here's a picture: > MGB Brake check switch 69-75 - Northwest Import Parts <

Have no idea what the red light next to your ignition switch would be.

I am not sure how useful the warning light is, I would think you would know that your brakes failed rather soon after they did not work.

With the "extra" hole in the dash, maybe I could install the warning light there, or replace the dash to get rid of the extra holes.

My car may have been originally a right-hand drive car, or the early B's were built ambidextrous, my firewall has a cup for a steering column
.

 

[Mickey Richaud]

The hole where the red light is was the location for the choke. And B firewalls were designed to handle both left- and right-hand configurations.