Rusty brake line
 

Gotta love BMW and their neat routing for hoses and hard lines. Traps dirt and moisture then rusts out the steel line. This is the rear brake line on our lower mileage X5. And yes, the stain is brake fluid. Other side is rusty but still dry.

Just wait until you run in to the fun waiting for you under the front driver side floor... plastic cover traps debris against the brake lines and rust them out there something fierce!

If yours haven’t failed there yet, pull the cover and do what you can now to try and salvage them... or just replace them now so you don’t have that sinking feeling at 65 mph on the outer belt...

This is why I rinse the chassis with water (at the self-serve car wash $2/time)
in the winter whenever temp is above 2-3C.

In April, I wash the chassis with garden hose. Rust accelerates in the hot months of June July Aug.

Don't blame BMW. It is lack of maintenance by the owner.

Oh come on.... I had a Ford F-150 that I ran in everything but good weather and the brake lines never failed on that beast... over 260,000 miles of sand, mud, snow and crap on that truck.

That said, I do agree that a good power wash is a good thing every now and then, but “hiding” the brake lines under that cover that really doesn’t let them air out was kind of a silly move... just saying...

I will be an expensive mistake.

We wash salt from our concrete driveway in the Spring to minimize damage to the concrete.

Every car is different Volvo, BMW, Ford etc.

Salt is corrosive to many materials: steel, aluminum, concrete etc.

My 1998 528i chassis is now 22 years old and it looks pristine underneath...

Was honestly something that I never thought much about until it jumped up and bit me in the butt... and I bet I’ve owned 40+ cars (this is the only one I’ve ever had a brake line failure on I will add)

Now that I have them fixed I actually drilled out my cover so that I could flush that channel every once and again and keep an eye on them... now [emoji106]

I also sprayed them with a healthy dose of rust inhibitor!

Oh, I'm well aware of the lines under the floor. I'm looking there as well. Will I find problems? I'll let all y'all know.



But calling this issue 'lack of maintenance' is just wrong. You'd have to pull the wheels, un-clip that cover, and wash out the dirt a couple of times per year. Had BMW simply used open clips to secure those lines (3 on the passenger, 2 on the driver side), dirt wouldn't accumulate to trap moisture. Just a bad design. And without removing the cover from the underfloor area, would rinsing it even get out the crud?


.

- We change engine oil, we replace spark plugs. Washing the car is routine maintenance.

- The TRICK for the big shield...

- In the DIY Fuel Filter I wrote a while ago, I showed the photo of a hole I drill in the big cover. This allows me to get a garden hose (no pressure washer!), and spray water up there a few times a year, especially in the Spring. TRUST me, this makes cleaning the brake lines a snap!!!

- Detail below how how to drill a hole large enough for the garden hose:

https://xoutpost.com/bmw-sav-forums/...-filter-4.html



https://xoutpost.com/attachments/x5-...one-hole-2.jpg

That is an extraordinarily clean undercarriage cn90. :jealous:

+1 to that!

I thought I kept mine relatively clean but that is amazing!

And exactly what I did, I actually drilled a few more along the bottom as well to allow water to flow through it better and drain [emoji106]

I was going to say the same. It doesn't look like ever gets driven! Nice!

In the winter, any days above 2-3C, I go to self-serve car wash (this way my driveway is not covered in ice!), and quickly wash the body from salt. Then I kneel down and spray water UPWARD. This way the salt is washed away.

A few washes here and there makes a BIG difference. Look around for self-serve car wash near your house. It is only $2-$3 per wash for me.

The rust you see above is from cars that are not given a chassis wash often...

The part where you see the rust (post #1) is covered by the wheel when the car is sitting on its four tires.

It does NOT matter, when you kneel down with a hose, you go around the car and spray water UPWARD.

So whether the wheel is there or not, it does not matter, if you aim the hose all around, water will gets everywhere to rinse the salt off.

The rusty brake line is completely enclosed by plastic, upwards spray will do nothing to remove the salt that has worked it's way in. I'm planning to cut a couple 2" holes to allow cleaning the brake lines on wife's.

I didn't put the plastic shield back on mine after replacing the rusty brake lines as I'm planning to replace one more piece that goes from the abs block to one of the back lines as it's rusty forward of the union also.

I have to agree with CN90. Judging from the OP's first pics... that car seldom gets an under carriage cleaning. Don't have to remove wheels or unclip the lines to get water on them, if done before dirt/grime has already built up that is. I was worried about my front lines under the cover after all the horror stories here, but they still look great at 120,000 miles. I clean the wheel wells regularly and the undercarriage at least a couple of times a year. We rarely see salted roads so I'm sure that helps but the few times we have I clean the undercarriage immediately. :dunno:

My undercarriage is not quite as clean as CN90's... but not far behind it either. Even seldom cleanings a couple of times a year makes a big difference it seems.

^None of that is saying that it's the best design from BMW either. But it is not a horrible or unsafe one if everything is kept from getting caked in garbage.

Edit: This is part of my twice a year under carriage cleaning:

https://i.postimg.cc/76vqpMWq/20160414_155909.jpg

https://i.postimg.cc/G2kbr8WG/20160414_163838.jpg

For the stuff you can get to underbelly spray will help but most is shrouded in plastic and the most common failure point in the brake line is included.

https://uploads.tapatalk-cdn.com/201...aae2b9b804.jpg

Those are my two rear brake lines after removal, the part completely shielded from any attempt at hosing off.

I do realize that some parts can be accessed and agree they should be hosed off especially early spring if you live where they salt the road.

BMW goofed in the fabrication of their steel brake lines. Either too thin of coating or too sharp of bends. They still lasted most of two decades but they could have lasted twice that.

^nothing that a scotch pad can't clean off...LOL
MINE LOOKED JUST LIKE THAT!

Mine was removed becauae the rust made it through to the inside of course.

If you get to it before failure clean it up and paint with some Rust-Oleum.

Original Poster lives in Alberta, where it is very cold in winter and a lot of salt is used.

Anyway, they use salt in Nebraska too, and you can see that I rinse the car often, even in the winter, my brake line looks fine.

I just cleaned the area under the plastic cover. Then I snap close ONLY one side and zip tie it. I leave the other side open so it is easier to wash, i.e., water can get in and out easier.

OK, after setting the job aside for a while, the cover is off and both lines are shot on both sides of the union. All that came out of the covered area was a handful of gravel and some dust. It wasn't packed with muck. Still both lines toast. Repair parts on the way.



Underside of the vehicle is otherwise clean(ish). Sure, there's a little surface rust on exposed parts, but up here we drive our cars regardless of the conditions. I'm not about to go crawling around under my car in -30C to get some dirt and salt off it.



Also bear in mind that we're talking about a 15yo car that might be worth C$4000 on a good day. 30 years ago, a car this old would be too rusty to even drive. This one (and our other X5, and the '08 535xi) don't have any rust spots anywhere on the bodywork. We even (gasp!!) park them in a heated garage every day, all winter, which is supposedly the worst thing you can do for rust.


So I've got that going for me. Which is nice...

Cinderella story... Coming out of nowhere.

... now about to become the Masters champion. [swings, pulverizes yet another flower] It looks like a mirac- it's in the hole! It's in the hole!

had all of our rear hard lines done a few years ago for $400 which was a pretty good rate now looking back on it...

That is killer. Dealer quotes are like $1200-1400


Sent from my iPhone using Tapatalk Pro

Couple comments:

1. The photo posted above by audiophool is interesting: only 2 out of 5 metal lines are rusted.
The other 3 lines seem OK. Reason?

2. Salt + heat (whether heated garage or 30C day in July-August) accelerates the corrosion process.
I am not advocating doing anything when it is -30C.
What I am saying is: any day above 2-3C, drive to a car wash place (I go to the $3 self-serve place so I can spray the water the way I want), do a quick clean of the body. Then rinse not only the body but also the chassis.
All I do is get a cardboard and kneel down to aim the water 45 degrees UPWARD under the chassis from the outside. Trust me, a bit water here and there on days > 2-3C helps a lot.
In fact, if you do this water wash religiously, you won't have any rust.

3. For the rear lines near the caliper as shown previously, go behind the car and aim water just BETWEEN the Rear Shock and the Rear Tire, water will get to theses metal lines.

Real easy answer. Two that are rusted are the brake lines where the cheap material used for a coating failed due to the bending by the supplier prior to assembly. Cheap materials, cheap coating = part failure. The other lines are a plastic/ polymer material not steel.
The brake lines will all fail in time. Those who live in a low humid temp area of the world will NOT see the end life as no rust develops on the exposed tubes.

For everyone one else it is When not IF. This failure is very common across whole segments of the auto world. You can even see complete brake line kits from aftermarket suppliers. Nope no BMW kits available yet just the braided lines from calipers to the frame points.

Examples
https://video.search.yahoo.com/searc...e&action=click

https://agscompany.com/ez-fit-chevy-brake-line-kit/

Wash the chassis on warm days during the winter.

But that assumes you do that since new. When you inherit the cat from P.O.s, you don't know how it was cared for but you can still wash the chassis to limit the damage.

The weakest point is shielded from any useful rinsing or observation. You can. Get in a couple times a year by removing the screws on the inboard side and bend the plastic down.

Nah, now these are fixed they'll surely outlast the rest of the car. Gave them a good blast of Krown before buttoning it up, just for good measure.



And since the 535 is about to go under the knife for new shocks (Bilstein B6 all around), it'll get a full inspection and whatever needs addressing will be done.