Just finished bleeding the hydraulics on my C4 and noticed a sizable leak from the front driver side caliper at the line connecting the 2 halves of the caliper. Anyone seen this? Do I need a full rebuild or just replace the short bridging hydraulic line? Part number 951.351.971.00

 

Have you tried to tighten the fittings on the inside, look like that's the one leaking ??

 

The leakage point seems to be at the union in the middle. The only adjustable pieces to that connecting line are on either half of the caliper. You can see the nut on each side where it connects. I don't see anything adjustable in the middle piece. I'm worried there may be another spot that may be trickling onto that spot, but I can't seem to find anything running down onto it. I'm hoping I just have to change out the middle piece. I don't feel like rebuilding my calipers at this point. Just finished a slow 4-month long engine reseal and I'm anxious to get on the road again.

 

There is no union in the middle, it's a solid piece of brake line with 2 ferrule nuts on either end. LOOK at the picture, and you can see that the inside ferrule nut plus surrounding area is wet, so there is a good chance it is leaking from that nut. Try to tighten it and see if that helps. Can't make it any clearer than that.

 

Clean and dry everything . And then after its dry, run your finger around your bleed nipples above. It may be that your leak is coming from the top. And just running down the sides to drip off the middle of that line. Don't over tighten the brake nipples. If one is perhaps cross threaded. It'll never seal. In this case, take a doner bleed nipple, cut three channels in the thread w a dremel and make a thread chaser out of it and renew the threads so you can get the bleeder in dead straight. Downs take a lot of pressure to seal it.

If it's the line, replace the cross line. But unless someone touched it, it should not be your issue.

 

Thanks for the replies guys. The leak is fairly obvious from the center ferrule. I also thought it might be one of the bleeder nuts but it doesn't seem to be the case. I even tried tightening the inner nut before posting about this but it did not help. The leak happens fairly easily with brake depression and by the looks of it, it seems to be coming from the center ferrule. No wetness on either nut. Just seems to be a strange point of leakage. Perhaps it may have happened when I recently removed and swung the caliper over while refurbishing the front axle. I have ordered a new crossline and will install it soon. Maybe then I can see if there's a break in that line. I will post photos if I find anything interesting.

 

Here is where the consensus is saying the leak is coming from.

Nothing a can of break fluid and some dry cloths couldn't help clear up....

Return after you have dried up 100% and have more information to provide.

 

It was not coming from any part of the connecting line. The fluid was just accumulating in the middle of the line as I suspected, but it was from a loosened feeding line higher up behind the caliper. The bizarre thing is that the flow pattern wasn't coming down onto the nut that you have an arrow pointed at. It was running on the outside of the inner half of the caliper and winding up on the ferrule as it passed behind then down. Tightened the feeding line and all is good. Saved $40 on a new line. Thx for the suggestions, guys.

 

Well you didn't give us that angle shot man...

 

Sorry, it was a tough angle from the inside that I couldn't even see, let alone take a pic. I ended up FEELING the brake fluid, not seeing it. It's funny how dumb you can feel when all you had to do was twist a nipple a bit more

 

Good thing is that it was a simple fix...