Master brake cylinder sensor leak (1 Viewer)

[sandcruiser90]

On my recently acquired HJ45 the two sensors are leaking. Damaged paint in engine compartment underneath. Not familiar with these. Had mechanic look at it and he recommends replacing with plugs since there are no wires connected to them doesn’t feel they are needed. When I turn the key, with cold engine,the brake buzzer and sometimes light comes on and then goes off after 15 secs or so after engine starting.
Thoughts on sensors (are they supposed to have wires connected) and is it normal for buzzer to go on like that.

 

[Pighead]

Pull those leaky sensors and put plugs in the holes. I had some wires on my '74s that slid on those sensors, never did figure out exactly what they did. Maybe lit up the brake warning light on the dash when you were all out of brake fluid and were gonna die. I dunno, never saw the light. Don't know if they even worked.

 

[bj40green]

This is how those sensors are hooked up.
They activate the parking brake light when there is no pressure (lack of fluid) in the master.

Rudi

 

[DougAustinTx]

Rock Auto has the sensors. I just replaced one of mine that was leaking. My wires are hooked up, but I have never seen the light come on..

 

[JohnnyC]

It is one wire connected to the two

It will come on when peddle depresses too far ... loose of pressure... missadjusted drums ... no brakes and about to die

It does work ... I lost my brakes at 30mph ... it came on lol

It would also come on a lot when I was running drums because I often ran without adjusting when needed

 

[sandcruiser90]

These do not seem to have any wires connected. Do not see any loose ones. The brake buzzer does come on when I turn the key (when cold) and stops after engine runs for 15-20 sec.

 

[bj40green]

These do not seem to have any wires connected. Do not see any loose ones. The brake buzzer does come on when I turn the key (when cold) and stops after engine runs for 15-20 sec.

I think you're referring to the vacuum buzzer.

 

[sandcruiser90]

Don’t know much about that. Can you explain how that works and why?

 

[bj40green]

Under the chassis, drivers side, is a vacuum tank with a pressure sensor.
Under the dash is a buzzer. If you loose vacuum or don't have vacuum for your brake assist, that buzzer will sound.
That buzzer is really loud and annoying so most people disconnect the wire on the tank. Problem solved!

Rudi

 

[davegonz]

Bump. I had the damn senders leak and ruin some of the paint on my fender. Anyone know the thread pitch/type so I can just plug them?

 

[Dadsfj40]

Same as the last post, converting 67 to dual cylinder and need to plug the holes, anyone know with what type of plug.