replace fuel and brake line mounts under the car?

[fritzenos]

Doing my new lines, some 25% of the male portion of the mounts have failed do to rust. They look like either "blind rivet nuts" or something similar with a threaded neck that the pipe clamps/holders are screwed into . I presume these are not parts available to aftermarket, welded from factory.

Has anyone done a repair of these, which type of rivet was used? It would be fun to find something that works in original dimensions. I would post a picture but again the forum has upload problems. I'll post asap a picture

[shogun]

do you mean # 7,8 and 9? http://bmwfans.info/parts-catalog/E3...double_filter/
7 holder 37206778082 https://www.ecstuning.com/b-genuine-...t/37206778082/
8 clamping 16121107928
9 holder 16121155060 https://www.ecstuning.com/b-genuine-...t/16121155060/
7 and 9 come with the screw

in 2006 somebody with a 750 had the same problem with replacing fuel lines under the car, some pics http://www.7-forum.com/forum/showthr...?t=54582&page=

[moroza]

You mean the male part of the line bracket mount, which has a female thread for the Philips M4x0.8 bolt holding the clip on? The part that Nos. 7 and 9 thread into? Those are welded to the unibody and not available separately. There may be a generic part like that, but I don't know what it'd be called. I'll call it a "post". One or two missing clamps, as long as they aren't next to each other, can be safely ignored. 25% may be a problem. If you can't find generic posts, I have two suggestions:
1. Grind down the remains of the old post to the sheetmetal, fabricate a new one using steel tubing with a nut welded on the end, welded to the unibody.
2. Grind down the remains and then drill through the floor, insert an M6 bolt from inside, and either
2a. weld it to the body, or
2b. put a nut on underneath to clamp it to the floor,
in either case, making it into a stud facing down. Then use a nut to hold the clamp to the stud. Use antiseize regardless.

Philips heads are frankly idiotic for this application. I replaced mine with stainless steel hex bolts with antiseize. Stainless can sometimes gall, especially to itself, but the antiseize should help, and if you really want to maximize/overkill the solution, use stainless bolts, nickel antiseize, and bronze nuts.

[fritzenos]

Thank you Moroza and Shogun, Attachment 667262

Yes here is the male part which is welded to the car. This one is OK but I have several with broken 4mm screw stuck in. A few I have drilled out and will try to salvage, but as you said, they are a poor design with the Phillips screw. I'd rather not work from inside the car, I don't want to rip carpet up.

I did find blind nuts or rivet nuts as they are called https://www.boltproducts.com/rivet-nuts-c-110.html, I may attempt to grind down the failed ones flush to the sheet metal, drill a hole, prime and paint, then install rivet nut to which I can bolt. We'll see if it works, I post pics.

Shogun, yes, the person from the German 7 forum had the same problem, one of his pictures show a broken screw stuck in the male "post".

All I can say is that anyone reading this post, take Moroza's advice and change your Phillips head screws to hex bolt ASAP before you face this problem, it's a pita.

[shogun]

These rivet nuts aka blind nuts or nut-ser looks like the solution for your problem.
I remember when we parted an 750iL years ago w/o any significant corrosion under the car body and we also wanted to remove all brake and fuel hoses, the biggest probs were these brackets with the male part welded to the car.

[eddycooper]

OK so I've got a similar problem on my E34. I've now got three of these phillips screws broken off, stuck in the "posts". Has anyone had success drilling the remains of the screws out? I tried an extractor on one of them, but I wasn't careful and I broke the extractor (its broken-off tip is now stuck in the hole).