Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

1999 A6 1,8T

Hi folks.
Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
rear calliper. As light was fading and working conditions were not great, I
only managed a brief inspection.
The connecting bolt was tight. However, I removed it & had a quick look
around. My question is whether there are meant to be any sealing washers on
the mating surfaces? (Non banjo shape, but banjo type connection) I suspect
not, as the block on the end of the hose seems to be machined flat but
leaving a bit of a spigot around the bolt hole. Does this spigot perform as
if a sealing washer? The surface of this spigot seemed somewhat pitted,
which surprised me. Checked everything was clean, reassembled and leak still
apparent. The fluid seems to seep under the head of the fixing bolt. The
fluid loss seems to be far more than I would have expected, Brake pedal will
reach floor without engine power assistance in about 10 seconds.

If no washers are employed I guess I'm looking to replace the rear hose
assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
Anybody out there replaced rear calliper, or hose/pipe?

Ian

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

Ian,
I've never worked on an A6, but chances are the mating surfaces are in the
end of the fitting, like a flare with a nearly matching bump in the socket
of the cast brake caliper. Usually such a leak does not appear out of the
blue, but following servicing in that area - like the replacement of a
rotor/pads or wheel bearing. Or, as in the case of my 5ktq's clutch master
cylinder, when the fitting is cross-threaded into the cast hole, and the
edge of the flare damages the seating bump at the bottom of the hole (local
dealer service did that - guess how happy I was) It is possible (although I
have yet to see it) that the mating surface could be galled and seal poorly,
or the fitting itself could be cracked in the threads, making it look as
though the leak is coming through the flare and up between the threads. If
it's a cracked fitting, be careful as the more you torque it, the more the
crack will open up and if the fitting shears off in the caliper, you'll have
to find a place to get a rebuild.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote in message
news:KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net...
> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great,
> I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers
> on
> the mating surfaces? (Non banjo shape, but banjo type connection) I
> suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform
> as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak
> still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal
> will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

Ian,
I've never worked on an A6, but chances are the mating surfaces are in the
end of the fitting, like a flare with a nearly matching bump in the socket
of the cast brake caliper. Usually such a leak does not appear out of the
blue, but following servicing in that area - like the replacement of a
rotor/pads or wheel bearing. Or, as in the case of my 5ktq's clutch master
cylinder, when the fitting is cross-threaded into the cast hole, and the
edge of the flare damages the seating bump at the bottom of the hole (local
dealer service did that - guess how happy I was) It is possible (although I
have yet to see it) that the mating surface could be galled and seal poorly,
or the fitting itself could be cracked in the threads, making it look as
though the leak is coming through the flare and up between the threads. If
it's a cracked fitting, be careful as the more you torque it, the more the
crack will open up and if the fitting shears off in the caliper, you'll have
to find a place to get a rebuild.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote in message
news:KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net...
> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great,
> I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers
> on
> the mating surfaces? (Non banjo shape, but banjo type connection) I
> suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform
> as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak
> still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal
> will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

Ian,
I've never worked on an A6, but chances are the mating surfaces are in the
end of the fitting, like a flare with a nearly matching bump in the socket
of the cast brake caliper. Usually such a leak does not appear out of the
blue, but following servicing in that area - like the replacement of a
rotor/pads or wheel bearing. Or, as in the case of my 5ktq's clutch master
cylinder, when the fitting is cross-threaded into the cast hole, and the
edge of the flare damages the seating bump at the bottom of the hole (local
dealer service did that - guess how happy I was) It is possible (although I
have yet to see it) that the mating surface could be galled and seal poorly,
or the fitting itself could be cracked in the threads, making it look as
though the leak is coming through the flare and up between the threads. If
it's a cracked fitting, be careful as the more you torque it, the more the
crack will open up and if the fitting shears off in the caliper, you'll have
to find a place to get a rebuild.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote in message
news:KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net...
> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great,
> I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers
> on
> the mating surfaces? (Non banjo shape, but banjo type connection) I
> suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform
> as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak
> still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal
> will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

A leak from the caliper P/B lever seal will run down around the brake
hose fitting and appear on casual inspection to be a leaking
hose/fitting. Careful inspection will confirm.
JR

Ian Gaskell wrote:

> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great, I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers on
> the mating surfaces? (Non banjo shape, but banjo type connection) I suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>


--
--------------------------------------------------------------

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

A leak from the caliper P/B lever seal will run down around the brake
hose fitting and appear on casual inspection to be a leaking
hose/fitting. Careful inspection will confirm.
JR

Ian Gaskell wrote:

> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great, I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers on
> the mating surfaces? (Non banjo shape, but banjo type connection) I suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>


--
--------------------------------------------------------------

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

A leak from the caliper P/B lever seal will run down around the brake
hose fitting and appear on casual inspection to be a leaking
hose/fitting. Careful inspection will confirm.
JR

Ian Gaskell wrote:

> 1999 A6 1,8T
>
> Hi folks.
> Sudden onset of leak of hydraulic fluid at the union of hydraulic hose to
> rear calliper. As light was fading and working conditions were not great, I
> only managed a brief inspection.
> The connecting bolt was tight. However, I removed it & had a quick look
> around. My question is whether there are meant to be any sealing washers on
> the mating surfaces? (Non banjo shape, but banjo type connection) I suspect
> not, as the block on the end of the hose seems to be machined flat but
> leaving a bit of a spigot around the bolt hole. Does this spigot perform as
> if a sealing washer? The surface of this spigot seemed somewhat pitted,
> which surprised me. Checked everything was clean, reassembled and leak still
> apparent. The fluid seems to seep under the head of the fixing bolt. The
> fluid loss seems to be far more than I would have expected, Brake pedal will
> reach floor without engine power assistance in about 10 seconds.
>
> If no washers are employed I guess I'm looking to replace the rear hose
> assy. ? Not sure how the flexible hose fixes onto the actual brake pipe?
> Anybody out there replaced rear calliper, or hose/pipe?
>
> Ian
>
>


--
--------------------------------------------------------------

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

In message <KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net>
"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote:

> My question is whether there are meant to be any sealing washers on
> the mating surfaces?

ETKA doesn't show any washers, but the pipe to the rear calipers is an
assemply of rigid pipe, flexible pip, banjo and bolt all as a single
part - 8E0 611 763 K for the LHS, and 8E0 611 764 K for the right hand
side.

--
Peter Bell (Note Spamtrap - To reply, replace 'invalid' with 'bellfamily')

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

In message <KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net>
"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote:

> My question is whether there are meant to be any sealing washers on
> the mating surfaces?

ETKA doesn't show any washers, but the pipe to the rear calipers is an
assemply of rigid pipe, flexible pip, banjo and bolt all as a single
part - 8E0 611 763 K for the LHS, and 8E0 611 764 K for the right hand
side.

--
Peter Bell (Note Spamtrap - To reply, replace 'invalid' with 'bellfamily')

Re: Sudden brake hydraulic fluid leak 1999 A6 1,8T
 

In message <KaSzf.47329$zt1.27565@newsfe5-gui.ntli.net>
"Ian Gaskell" <welbeck@wotnospam.BTInternet.com> wrote:

> My question is whether there are meant to be any sealing washers on
> the mating surfaces?

ETKA doesn't show any washers, but the pipe to the rear calipers is an
assemply of rigid pipe, flexible pip, banjo and bolt all as a single
part - 8E0 611 763 K for the LHS, and 8E0 611 764 K for the right hand
side.

--
Peter Bell (Note Spamtrap - To reply, replace 'invalid' with 'bellfamily')