S8ilver

Ok, so was making record time on a brake line install. Fronts went together perfectly and bled without a hitch. I am using a pressure bleeder and start at about 10-12 psi.

Then I get to the rears. Everything seemed to be going smoothly...hit torque on banjo bolt, topped off and pressurized system, and bleeding was going smoothly I thought. I gave everything a little tap to free up those little tiny bubbles, and little tiny bubbles came out. However, I just kept getting very very small bubbles. I built pressure back up and gave it a few minutes...it dropped 1-2psi. After very very close inspection, the surface between the fitting and the lower copper washer (supplied by ECS with the kit) had just the tiniest hint of sheen to it. I wiped it dry to make sure I wasn't seeing things, and several minutes later, I confirmed it was leaking. Had I not noticed the very very small bubbles or the moisture on the washer I would have just cleaned up and drove as normal.

What am I doing wrong here?...I put the factory lines back on, no leak. I tried other copper washers with the ECS kit, same result. The fittings bedded very nicely into the washers as well. I'm stumped. Return the crap? Try aluminum crush washers perhaps? The fittings seem to be machined perfectly, and the caliper surface is nice and flat as well.

The moisture you see in the photo is not the brake fluid leaking, but just brake cleaner that didn't quite dry yet (yes, that's how fast and smoothly everything was going together before I threw in the towel.

Kneale Brownson

Could the leak be from elsewhere on the crimped-on hose end that works its way to where you see it?

What's wrong with OEM hoses, anyway?

S8ilver

The rest is bone dry...just seeps at the washer.

Haha nothing 'wrong' with OEM lines. Nothing wrong with OEM wheels, rotors or pads either, but I'll change those too. I like to tinker. For $25/corner, braided stainless lines seemed worthwhile. If different washers don't do the trick I'll leave the OEM at the rear and call it a day. ECS assured me that no one has ever had this issue before. I might have just got a bad line.

Kneale Brownson

Could be bad crush washers, although you said they supplied several.

Problem with stainless steel lines is they were developed for folks who race--and replace the lines regularly. All the time I read about Audi owners using wheels requiring spacers, brake lines requiring extra care, lowering springs or other suspension adjustments (Allroad airbag reconfiguring, for example) and wondering why their axles wear unusually or wheel bearings fail, etc., and mostly they are cosmetic "improvements" or attempts to make their street car into a track car. Audi engineers do a pretty good job of designing for a purpose. They make your S8 for those wanting a sportier A8, for example. Neither seems to me to be a reasonable track car. A dedicated track car can give you lots of tinker time. Just a perspective.

silverd2

Well stated, Kneale.

I didn't buy a 2 ton 4-door car for street (or track) racing. I moved from Porsche to the D2 for a change...in roominess, ride quality and luxury..while still retaining German precision, plenty of power and great, predictable handling. I have never felt safer in or enjoyed driving a car one bit more.

Even with a budget plenty adequate at the time, I consciously chose an A8 SWB over the S8...didn't feel the "enhancements" of the S8 fit what I wanted, compromised the feel I wanted...and not worth the big loss of mpg's and price premium for items I didn't want. If I wanted a car designed around max performance, it would be back to Porsche.

OEM is great and I just strive to maintain what Audi engineered...with the exception of small improvements they made later, but only those related to my model...example: Improved (less likely to leak) design of the driveshaft output flange.

S8ilver

I completely know what you mean...understated elegance is how I describe the D2. I drive maybe 50-100 miles a week and that's why I picked my S8. If I had a commute or went on long drives I'd probably be in an A8 myself. I spent a solid year looking for the car, and it was exactly what I wanted. My last was an E34 M5...great 4 door, plenty of power, and the German precision you're referring to. But, it was a manual and just not comfortable enough. For me the S8 was the perfect balance between the sport and comfort (I did get the executive seat option

While I agree with all your input, I was just after a bit better brake feel. I don't race, I don't track the car. I will replace these lines with OEM and return these leaky pieces of junk. It was a $100 project that just turned into a headache. All of my friends say "change this, paint this, lower this" but I bought the S8 because I wanted an S8 pretty much as the S8 came. A bit of improvement here and there is fine in my book. I tinted the windows, I added a powered subwoofer to the treble heavy stereo, and will do some different wheels at some point (Audi OEM style of course).

Cheers

S8ilver

Ok so it turns out the fittings are absolutely fine. What I had failed to mention in my previous post was that the issue I was having was only on the passenger side. I spent so much time trying to get that to seal I didn't even attempt the other side. I emailed back and forth with ECS and they sent me some more washers just for the heck of it. I went right to the drivers side and everything went perfectly. The line bled within minutes and I was bubble free. the difference between the sides now seems clear to me. I recall using quite a bit of effort trying to crack the bleeder screw open on passenger's side caliper. This was my first bleed as I've only put 10k miles on the car since I bought it. I'm convinced the screw was overtorqued on its last service, and once I broke it free it would never seal up again. I believe it's pulling in air at the screw itself.

So the question...only option is to replace the caliper(s)? I've found Centric and TRW replacements...Centric for $65+$125 core, and the TRW for $225 with no core. What brand are the OEM? I remember seeing a stamp on the housing somewhere, but definitely wasn't Audi. Oh, and found replacements (still not sure of brand) thruough Audi parts wholeseller for $267.

Why didn't Brembo just come on the rear as well? Any advice/input greatly appreciated.

silverd2

Pretty sure it was TRW...listed as OEM with most suppliers. Easy to get Brembo rear rotors at reasonable prices.

TRW is generally good stuff...some of the best suspension arms around for D2's and other cars. TRW automotive is not actually part of the original American TRW company...Got bought out by Fuji Valve Co (I believe) and retained the TRW name. High quality stuff, though, in my experience.

Both available at PartsGeek.com...one of my favorite suppliers...quick and correct.

S8ilver

Thanks Silverd2,

Partsgeek was exactly where I was looking, and yes they list TRW as OEM...and dealer-listed "Audi OEM" from genuineaudiparts.com (GAP), the best source I've found for those hard to find "dealer only" items that you don't want to pay "dealer only" prices for. For example, needed center caps for 2007 S8 wheels I just purchased (pics soon hopefully, still deciding on tires). Dealer wanted $60 each and I think I paid $36 from GAP. Trunk release switch cracked in half...$38 from dealer, $18 at GAP. Their prices can fluctuate but always a decent savings. I'm rambling again. Out.

Kneale Brownson

AudiUSAparts.com is another dealership online parts system with pretty fair pricing. It's Sunset Imports Porsche Audi in Oregon.