2000 A6 4.2 Brake Caliper leaking after replacement
07-26-2014, 07:21 PM
#11
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You can reuse the factory copper washers no problem. As a matter of fact, they work better than the new ones that come with replacement calipers.
The factory washers are thicker, they also have ridges cut into them so they seal better with less torque.
Note: they have to be the ones that came off of that particular vehicle, and reinstalled in the same orientation that they came off.
The leak is not on the threads most likely. I'm betting it's it's coming from the copper washer area by the bolt head. Note that these use banjo bolts that are basically hollow to allow fluid to pass through them.
No sealants, teflon tape, or any other chemical may be used in a braking system except for brake fluid itself. It is vitally important that the system seals itself mechanically. Not only does the system get extremely hot, it also is under a considerable amount of pressure (think 2000 psi in some cases).
The factory washers are thicker, they also have ridges cut into them so they seal better with less torque.
Note: they have to be the ones that came off of that particular vehicle, and reinstalled in the same orientation that they came off.
The leak is not on the threads most likely. I'm betting it's it's coming from the copper washer area by the bolt head. Note that these use banjo bolts that are basically hollow to allow fluid to pass through them.
No sealants, teflon tape, or any other chemical may be used in a braking system except for brake fluid itself. It is vitally important that the system seals itself mechanically. Not only does the system get extremely hot, it also is under a considerable amount of pressure (think 2000 psi in some cases).
Will stay away from Sealants then. Thank you.
07-27-2014, 01:43 PM
#12
You can reuse the factory copper washers no problem. As a matter of fact, they work better than the new ones that come with replacement calipers.
The factory washers are thicker, they also have ridges cut into them so they seal better with less torque.
Note: they have to be the ones that came off of that particular vehicle, and reinstalled in the same orientation that they came off.
. . . .
The factory washers are thicker, they also have ridges cut into them so they seal better with less torque.
Note: they have to be the ones that came off of that particular vehicle, and reinstalled in the same orientation that they came off.
. . . .
They are designed to crush when tightened and act as a gasket.
The ridges you see are not put in the washers when they are made, but are the result of this crushing.
When the copper is crush it becomes "Work Hardened" and will no longer work to form a seal as well the second time.
Lots of facts (and non-facts) here. (Fairly easy to tell who knows what as you read.)
Last edited by N_Jay; 07-27-2014 at 01:47 PM.
07-27-2014, 06:51 PM
#13
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The sealing washers are Annealed Copper (Very soft) "Crush Washers".
They are designed to crush when tightened and act as a gasket.
The ridges you see are not put in the washers when they are made, but are the result of this crushing.
When the copper is crush it becomes "Work Hardened" and will no longer work to form a seal as well the second time.
Lots of facts (and non-facts) here. (Fairly easy to tell who knows what as you read.)
They are designed to crush when tightened and act as a gasket.
The ridges you see are not put in the washers when they are made, but are the result of this crushing.
When the copper is crush it becomes "Work Hardened" and will no longer work to form a seal as well the second time.
Lots of facts (and non-facts) here. (Fairly easy to tell who knows what as you read.)
I have reused factory washers countless times, and guess what? They seal EVERY time. Unlike the new washers that are nearly half as thick and, more often than not, don't seal, and require A LOT more torque to get them to seal. To the point where you're about to break things.
And I'm quite aware that they're a crush washer and I'm very well aware that the ridges that are cut into them are from assembly and not made that way. (The ridges are in the brake hose connector)
However, being that the factory washer is over twice as thick, and being that it is copper; a relatively soft metal, it can reseal a second time with no issues.
Yes, technically you're supposed to replace them, however, the new ones are really bad, worse than the used ones, unless you get factory washers.
07-27-2014, 07:29 PM
#14
Maybe a few new, proper (not eBay special), washers?
If you use the old washer and it works, great.
But when it doesn't to keep trying is foolish.
Last edited by N_Jay; 07-27-2014 at 07:32 PM.
07-28-2014, 07:07 AM
#15
AudiWorld Super User
So anneal the copper washer(s). Put them on an electric stove element (clean them first), heat them red hot, remove them from the stove and let them air cool.
07-28-2014, 07:13 AM
#16
AudiWorld Super User
Hi all, I recently replaced the rear brake rotors and also put in reconditioned brake calipers. The right wheel is fine but the left drivers side wheel started dripping brake fluid after I started to pump the brakes to get brake pressure back up.
I took off the brake line again and reconnected it a couple of times and tightened it as hard as I could without damaging the bolt and the caliper. That seemed to help but it still keeps dripping a bit.
Not sure what else to do. Is there any kind of sealer I can put around the edges of the nut? Thanks.
I took off the brake line again and reconnected it a couple of times and tightened it as hard as I could without damaging the bolt and the caliper. That seemed to help but it still keeps dripping a bit.
Not sure what else to do. Is there any kind of sealer I can put around the edges of the nut? Thanks.
07-28-2014, 07:18 AM
#17
AudiWorld Super User
There are many metal washers/seals on the car, among them are the power steering connections at the power steering pump and essentially any banjo bolt-type fluid connections. I've worked on motorcycles and cars for over 50 years…annealing used copper washers is a common solution to reusing them. New ones are the best, but annealing works well.
07-28-2014, 07:26 AM
#18
AudiWorld Super User
The only washers I see are the ones on the end of the brake line which has a metal connector that the bolt goes thru. It has a washer on either of the connector. They don't look like they're made of copper and they are the ones that were on the car when I got it. I will look for copper ones and try those. Thanks.
07-28-2014, 11:34 AM
#20
AudiWorld Super User
