Master cylinder ESP sensor leak

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
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

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Yuri, does Bentley cover replacing the sensor?
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
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

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS
Oh, man, hopefully Brian will come along and provide some guidance. I hate brake fluid (when it's not contained)!
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
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 (this had been replaced by a hack shop far from here - with used parts...)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

Veteran Member
Joined
Oct 29, 1999
Location
North Palm Beach, FL, USA
TDI
One '13 JSW_TDI & One '04 Variant_TDI
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

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
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...
 
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