StopTech SS Brake Line Installation Tip - The Unofficial BMW M5 Messageboard (m5board.com)

Need4Spd · 3rd June 2003, 09:11

I don't know how many of you will trust yourselves to do your own brake line swap, but here's a tip from first-hand experience. First of all, Dave Z has excellent instructions on removing and replacing the brake lines as part of his tech tips on installing big brake kits, so be sure to follow them.

When you install the new lines, attach the end to the caliper first, as you have to rotate the entire line around and around until it's snug, then tighten it down with a 14 mm wrench. If you attach the line to the hard line fitting first, you won't be able to rotate the caliper end into position.

The additional tip I'll add to Dave Z's instructions is that when you get the old brake line off, you'll see that the hole through the bracket where the brake line passes is a tad too big for the StopTech fitting, which allows the 1/2 in. StopTech line to sort of go right through it. (BTW, I'm not picking on StopTech at all; all aftermarket lines seem to have the same size fitting, though from the pictures, it looks like the lines that come with the Mov'it kit have big fittings like the stock lines.)

Actually, on my car the hole in the bracket is star shaped. The mating side of the fitting on the stock brake line has four "teeth" in it that engage the tips of the star so that it doesn't rotate. The shoulder of the brake line fitting where it goes into the bracket as you can see is also very big and square, so it doesn't pass through the hole. The shoulder (sides of the nut) on the StopTech line fitting is only barely larger than 1/2 inch fitting itself, so can either rock at a funny angle in the hole or go through it entirely.

What you need to do is go the hardware store and get some big washers with 1/2 holes. If you pass the brake line fitting through the washer first then put it to the hole, your line will no longer rock at a funny angle or push through the hole in the bracket. I don't know why they don't include these washers in the brake line kits. You need them to do the install unless there's something I'm missing about this. You will need one washer for each line. Get stainless ones if you can find them, or galvanized ones, as they will be exposed to the elements under there.

Unless you can find a washer with inside "teeth" that'll mate to the star in the bracket like the stock one, the new brake line fitting can rotate around a small bit. I don't think that will hurt anything, but it's another potential wear item that you should check at every inspection interval to make sure the bracket isn't cutting through the brake fitting or vice-versa.

The other tip I'll pass along is, if you're changing your brake pads at the same time you're changing to SS brake lines, be sure to compress the caliper piston back into the bore BEFORE you remove the stock line. If you do the brake line first, it will of course have air in it, and when you compress the piston back into the bore, you will push that air upstream into the master cylinder. Don't ask me how I know that.

Oh yeah. One final thing. Dave Z is absolutely right about using a flare nut wrench. The metal on the fitting is very soft and you WILL round it if you don't use the a flare nut wrench. Even if you do, be sure the wrench is square with the sides of the nut, or you will round it even with a flare wrench. It's very easy to get the wrench off-kilter with the nut because there really isn't much room there between the shock, the sway bar end and the brake line fitting. Be patient and work the flare nut wrench carefully onto the nut before trying to loosen it. It's fairly tight, but once it breaks loose you can turn it easily with an open end wrench or your fingers (I'd try it with fingers first, as you can't round the nut with your fingers!).

OK, so if you're now too intimidated to do this yourself, go ahead and have it done by a real mechanic and don't feel bad. There is no shame in having brake lines worked on by a professional, and your life is not worth a hobby experiment if you have any qualms about doing this yourself.

SouthshoreM6 · 3rd June 2003, 19:41

Need4spd,

Great writeup! I am on backorder for the same parts from DaveZ. Just wondering if you've had a chance to give the new pads a work out? I am really hoping to cut down on brake dust in addition to helping the car stop better.

I would appreciate any comments you might have.
Regards,
Bill

DZeckhausen · 4th June 2003, 07:15

Quote:

Originally posted by Need4Spd
Oh yeah. One final thing. Dave Z is absolutely right about using a flare nut wrench. The metal on the fitting is very soft and you WILL round it if you don't use the a flare nut wrench. Even if you do, be sure the wrench is square with the sides of the nut, or you will round it even with a flare wrench. It's very easy to get the wrench off-kilter with the nut because there really isn't much room there between the shock, the sway bar end and the brake line fitting. Be patient and work the flare nut wrench carefully onto the nut before trying to loosen it. It's fairly tight, but once it breaks loose you can turn it easily with an open end wrench or your fingers (I'd try it with fingers first, as you can't round the nut with your fingers!).

Even using a flare wrench, it is possible to run into trouble with an E39 front brake line. There is very little room to maneuver and the fitting is very poorly designed and very soft metal. I had a customer stop by for a pad and line swap and I could NOT free the passenger side front line. Even with the flare wrench, the fitting started to round. I simply gave up and left it to another day. This was the first time I was EVER unable to remove a brake line fitting, by the way. But it had a major effect on my confidence level. What if this had been a big brake installation? Yikes!

I just purchased a new type of flare wrench by Facom that goes ALL the way around the fitting. How does it do that? By opening and closing.

Ordinary flare wrench

Facom super-duper flare wrench

Griots Garage offers a set of 7 metric flare wrenches for $260. You can buy them individually from Ultimate Garage for just $22 each. So I bought a 10mm and an 11mm. For BMW, you want the 11mm size.

I used the new wrench when I installed the Brembo kit on my own car last week. I think it may be just what I need to go back and finish that M5 front line swap. I'll let you know how it works out.

Need4Spd · 5th June 2003, 05:06

Facom super-duper flare wrench? I sure could have used one of those! BTW, Dave, what are your thoughts on the washer issue I identified above? PM me if you want to share your thoughts privately.

DZeckhausen · 5th June 2003, 05:21

Quote:

Originally posted by Need4Spd
Facom super-duper flare wrench? I sure could have used one of those! BTW, Dave, what are your thoughts on the washer issue I identified above? PM me if you want to share your thoughts privately.

I'm supposed to call the engineer at StopTech to discuss this because there are "ramifications" if a washer is used. I didn't have time to place the call today, so I'll try to follow up tomorrow.

By the way, I gave the Facom flare wrench its first test today on a Subaru WRX. It didn't pass the test!

The wrench seems to pop open when you really crank on it hard. This may not be the solution I was hoping for after all. I'll continue to evaluate it and let you know. In the meantime, don't rush out and order these.

Need4Spd · 5th June 2003, 08:37

Quote:

Great writeup! I am on backorder for the same parts from DaveZ. Just wondering if you've had a chance to give the new pads a work out? I am really hoping to cut down on brake dust in addition to helping the car stop better.

The Axxis Deluxe Plus pads are nothing short of terrific. I actually put these on a few months ago when supply was not a problem. They were highly recommended by DaveZ. Quiet, with very low dust and good stopping power and fade resistance.

I ordered the brake lines at the same time, but was too lazy to put them on until recently. Wish I hadn't waited so long.

DaveZ, as to the "ramifications" you're talking about, I'm anxious to hear because I don't see any way of putting these lines into the car without them. They will not seat square with the hole in the bracket without them. I had the same issue when installing these lines in my M Roadster, too (which I also got from you). On that car, the lines would go right through the hole without the washer. How did you do yours? Anyway, I can't see how there would be much harm since having it pass through the hole in the washer (the ones I got are about the same diameter as the bracket surface) isn't much different than having it pass through the bracket itself. But if this is a safety problem, I really want to know!

Also, since the front lines and brakes do most of the work, I haven't gotten around to putting the lines into the back on either car yet. I noticed while surfing the web the other day that while the StopTech official web site lists for the M Roadster the same lines on the front for the M3 (e36), there is no part no. for the rears on the M Roadster. I have the rear set (4 piece) from you which says they're for the M3, and I just assumed these would be the same for the M Roadster since you list them on your site, but now I'm not sure. I assume you've actually put these in an M Roadster, but can you confirm they'll fit before I jack my car up and take off the wheels?

And thanks for sharing your experience with the super duper Facom flare wrench. I'll hold off getting one until I hear back from you to see if it really works. Part of the problem with the clearance on the flare nuts in front are those electronic boxes that are near the lines and interfere with the wrench. I assume these boxes are the smarts that tell the ABS/DSC/Tire Warning systems how fast the wheels are turning. Add that obstacle to the sway bar links and you have VERY little room to swing that wrench around or square it up with the flats on the flare nut.

SouthshoreM6 · 5th June 2003, 11:11

Thanks for the feedback on the pads. Sounds really good to me since I am soooo tired of all the cleaning to keep the ACS rims looking good!

DZeckhausen · 5th June 2003, 17:22

Quote:

Originally posted by Need4Spd
DaveZ, as to the "ramifications" you're talking about, I'm anxious to hear because I don't see any way of putting these lines into the car without them. They will not seat square with the hole in the bracket without them. I had the same issue when installing these lines in my M Roadster, too (which I also got from you). On that car, the lines would go right through the hole without the washer. How did you do yours? Anyway, I can't see how there would be much harm since having it pass through the hole in the washer (the ones I got are about the same diameter as the bracket surface) isn't much different than having it pass through the bracket itself. But if this is a safety problem, I really want to know!

I am sure it's not a safety issue, as I'm familiar with the set-up and how it all goes together. I'll let you know as soon as I talk to Steve. It's probably a supply issue given that the size may not be standard and the "ramification" may be a price increase if the washers have to be custom made.

Quote:

I noticed while surfing the web the other day that while the StopTech official web site lists for the M Roadster the same lines on the front for the M3 (e36), there is no part no. for the rears on the M Roadster. I have the rear set (4 piece) from you which says they're for the M3, and I just assumed these would be the same for the M Roadster since you list them on your site, but now I'm not sure. I assume you've actually put these in an M Roadster, but can you confirm they'll fit before I jack my car up and take off the wheels?

Good catch! They won't fit, as the M Roadster and M Coupe (all years) have a single, long rear brake line to each caliper (2-piece set) that is unique to that platform. That is probably my mistake when I was building my web site. I'll need to review my records and make sure I didn't sell any more rear lines to M Roadster/Coupe owners. In the meantime, I'll get with StopTech and have them fabricate the proper lines for you and will send a UPS call tag for the E36 M3 rear lines that I stupidly sent to you. You just need to have them in a plain box with no labeling. The UPS dude (or dudette) will have the proper address sticker. I'm really sorry about that!

Quote:

I assume these boxes are the smarts that tell the ABS/DSC/Tire Warning systems how fast the wheels are turning.

These are merely junction boxes which offer some weather protection to the plugs that connect the brake pad wear sensor (on the driver's side) and ABS sensor harnesses to the car's main harness. You can flip the door open and look inside to see for yourself. You'll need to do this anyway if you ever replace a pad wear sensor.

Need4Spd · 5th June 2003, 19:23

Quote:

In the meantime, I'll get with StopTech and have them fabricate the proper lines for you and will send a UPS call tag for the E36 M3 rear lines that I stupidly sent to you. You just need to have them in a plain box with no labeling. The UPS dude (or dudette) will have the proper address sticker. I'm really sorry about that!

Dave, you're awesome!

DZeckhausen · 5th June 2003, 21:56

Quote:

Originally posted by DZeckhausen
I am sure it's not a safety issue, as I'm familiar with the set-up and how it all goes together. I'll let you know as soon as I talk to Steve. It's probably a supply issue given that the size may not be standard and the "ramification" may be a price increase if the washers have to be custom made.

Just got off the phone with Steve. It's not a safety, availability, or pricing issue. He was concerned that the outside diameter of the washer might impinge on any features that are in place to keep the factory line from rotating. For example, the Subaru WRX I did yesterday had a hex fitting, just like the StopTech line, and a ridge was stamped into the factory mounting platform to keep that hex from rotating when the hard line fitting was tightened. A washer would not work in that case. I explained that the BMW mounting surface was flat, so a washer would have lots of room and wouldn't hit anything.

They are going to bring another car in to measure, just to be sure. In the meantime, I've asked them to include washers in the couple of BMW line orders I've placed today and will continue to do so until it becomes standard.

It's not required for all models and even the E39 has enough variation in the factory mounting plate to not need this washer in most cases, most significantly not in the test mule for the original kit. The Goodridge lines that came with my Brembo big brake kit had even smaller hex fittings andthey DID pull through on my 540i/6 while the Mov'it kit's lines did not. I'll be giving some feedback to Brembo to include a washer in the lines that come with their big brake kits too.