Master cylinder ESP sensor leak

[ymz]

Just replaced my master cylinder... while bleeding the top of the system, I got a leak coming from the ESP sensor... when removing it from the old master cylinder, there was no sealant present... is any supposed to be there on the threads? (yes, it's on as tight as I can get it...)

Thanks,

Yuri

 

[UhOh]

Yuri, does Bentley cover replacing the sensor?

 

[ymz]

Nothing specific... ETKA doesn't show any "O" ring or sealant... I don't see any reason for it leaking... unless the sealing surface or threads on the new Master Cylinder are out of spec...

Yuri

 

[UhOh]

Oh, man, hopefully Brian will come along and provide some guidance. I hate brake fluid (when it's not contained)!

 

[ymz]

I'll wait for some suggestions, but one possible "solution" - put the old master cylinder back in... I did notice that when I removed it there was no rubber "O" ring (not really, just a gasket) between the booster and the master cylinder... (this had been replaced by a hack shop far from here - with used parts...) Perhaps that was why the brakes were wonky...

Yuri.

 

[where2]

Is this a spot where this is supposed to be a copper crush washer between the sensor and the master cylinder?

Typically at the pressures the brake system runs at, things get sealed by flares. Being a sensor, I could see it more like an oil pressure sensor using a copper crush washer to limit fluid migration.

 

[ymz]

No crush washer indicated... put in the old master cylinder... no leak... I don't see them having changed the physical dimensions of the threading...