Brake Hose - Beat A Dead Horse

Hi All,

I am new to this forum. Yes, I did the proper searching but I am sorely confused. The front brake hose on my 2002 R1150RT busted. I think I found the part, but I am confused to the rafters about bleeding.

It's the small (2") hose above the caliper on the right side of the front wheel.

Do I really need to bleed from the spot under the tank or can I just do it by using the handle bar reservoir?

Hi vindicated.

Welcome to BMWST.

Bleeding your bike is a long winded process (relatively speaking).

Your bike has iABS which is a servo assisted braking system.

It is divided into circuits, of which, there is one circuit that goes from the front brake lever to the Servo module under the tank. Then, there is a second and in terms of fluid, seperate system that goes from the Servo unit down to the front wheel.

It makes sense to replace your brake lines with braided stainless steel items now (as you know your original ones are dying).

Then do a complete (front and rear) fluid flush of all systems.

Here is a walkthru that is clear and straight forward:

http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

Hi All,

 

I am new to this forum. Yes, I did the proper searching but I am sorely confused. The front brake hose on my 2002 R1150RT busted. I think I found the part, but I am confused to the rafters about bleeding.

 

It's the small (2") hose above the caliper on the right side of the front wheel.

 

Do I really need to bleed from the spot under the tank or can I just do it by using the handle bar reservoir?

Morning vindicated

Yes you do as the fluid reservoir for the front calipers is under the fuel tank. If you try to bleed from the handlebar lever reservoir only you will quickly run the wheel circuit side out of fluid.

Additional thoughts:

This would be a good time to replace all the lines with a nice braided stainless kit before you have another failure. I've had good results with Spiegler. Anton Largiader recommends Bud from Nickwackett Garage and I certainly wouldn't discount his opinion.

If your brake pads and disks aren't brand new, use the wood blocks (or really expensive factory tool) as specifeied in the procedure or you will end up with the reservoirs overfilled at the pump and will pump out fluid when you push the pistons back for service at some point.

On that note, unless you know the last person did it right, evacuate the reservoirs at the pump (suck most of the fluid out) before you push back the pistons to insert the blocks.

While you have the brake fluid flowing, get the bleed adapter and bleed your clutch circuit as well. If the fluid comes out all dark and nasty, consider removing the clutch slave for inspection to make sure it hasn't started to leak already.

Tell us where you are located. If you are lucky, someone nearby may have the tools and experience.

 

On that note, unless you know the last person did it right, evacuate the reservoirs at the pump (suck most of the fluid out) before you push back the pistons to insert the blocks.

Afternoon rxcrider

He popped a brake hose so there can't be much fluid left in that reservoir.

I wasn't sure if he meant the upper hose or one of the lowers - if he upgrades them all, I guess it wouldn't matter anyway.

OOPS - just re-read the post and had missed the line about the hose being just above the caliper - yep, it is probably pretty darn empty

Let's just pretend that was in reference to the rear circuit that may as well be bled at the same time. Yeah, That's the ticket.

Since you put in the title, I will beat that dead horse...change out your brake lines!! Preferably with braided SST ones. This incident with that front caliper line "was your sign". Heed it.

Welcome to the board. Where are you located? There may be a member near you that will be willing to assist.

Hey, ltlJohn, NICE avatar!!

I'll second the recommendation of rxcrider re Spiegler.

My front right caliper did a "partial seizure", as in it got really hard to turn the front wheel. Several hours or wrenching later the problem was found to be decomposed rubber crud clogging the passages between the two halves of the caliper. Caliper pistons and rubber "rings" were pristine, perfect. Only source we could come up with is decomposing brake lines. An old Triumph/Honda/younameit motorcycle mechanic said this is a very common problem in bikes older than 10-12 years. So I decided to replace them all. DOT4 fluid is nasty stuff.

I did a lot of internet searching and saw the vid on sport bike track gear with the owner of Spiegler. Then I went and bought some off brand local "reusable" components and UNCOATED braided AN3 hose to get me thru an upcoming planned trip. BIG mistake. It was a LOT of TIME, WORK, and MONEY to make these up, get them fitted, leaks stopped, and system bled. Missed the trip working on this. And they are not sleek or trim.

Back to Spiegler: I ordered a full set of their hoses from amazon. (Saved about $40 over sportbiketrackgear, but sold by the same on amazon. ?? Look it up) However, the kit was for a R1100RS. Slightly different from my R1100S. I called Spiegler, got the "Director of Dealer Development", Brian Hart, by chance, who is swamped but VERY helpful. Returned the kit, got a quote on a mod and the clutch lines and am VERY happy with the service, price and quality.

QUALITY - Two important things I learned the hard way and would like to pass along:

1) COATED braided stainless steel over PTFE tubing brake lines are what you want. COATED means there is a clear or colored plastic sheath or "coat" OVER the stainless steel braid. WITHOUT the plastic sheath, whatever the brake line touches (fenders, fairing, wiring, etc) will be CUT by the vibration, shaking, movement of the bike and the hose.

2) being able to rotate the end fittings (banjos) on the line is HUGE. These brake lines are "flexible", but they DO NOT TWIST. Trust me. But Spiegler fittings do, and Spiegler includes the plastic tools to rotate the fittings without scratching the finish on the hose or fittings.

Spiegler also hand labels stickers on each hose so you know where it goes.

These hoses are about half the OD of the stock hoses, but they are GORGEOUS. YOU WILL LIKE THEM, and they will outlast you and the bike.

BLEEDING the system is another issue altogether. DOT4 brake fluid WILL EAT PAINT and PLASTIC, IMMEDIATELY. COVER EVERYTHING AND KEEP IT COVERED. Some people go to DOT5 and avoid this problem. Look at the Mityvac MV8000 brake bleeder kit for $30-40. Lots of utubes and other info available online. Several good reasons to pull the new fluid into the bottom of the system instead of pushing from the top.

I don't recommend using DOT 5, as suggested above, in a system designed for DOT 4.

Dot 5 is a synthetic blend while Dot 4 is a mineral blend. They are not compatible.

Regards, Ron C.

Don't use Dot 5 in these bikes. They are not interchangabe.

Furthermore, from Opie Oils web site.

"Silicone based DOT 5 was originally introduced to give higher temperature performance over glycol DOT 4.

Silicone fluid also has other advantages, it does not damage

paintwork and it does not absorb water.

HOWEVER, silicone fluid is a poor lubricant and does not lubricate ABS pumps as well as PAG fluids. It is also more compressible than PAG fluids, which can result in a

sluggish or spongy pedal.

It therefore requires special design considerations in braking systems. Further, because it does not absorb water, any water remains as globules, which can pool in low

spots in the system and cause corrosion. This water can vaporise when heated under heavy braking giving a disastrous effect on braking efficiency"

Dot 5 is a silicone based brake fluid and should not be mixed with other Dot numbers. Dot 5.1 is the new kid that is compatible with 3 and 4. It has a higher dry and wet boiling point than the lower numbers. That could be used next time you bleed your brakes or clutch. Mike

RonC, you are correct, they (DOT4 and 5 brake fluid) are NOT compatible, in that they separate like oil and water when combined. However, if one is completely replacing the brake lines, I'd be very tempted go a little farther and clean out the calipers and reservoirs and convert to 5.

DOT5 has a higher temp boiling point and DOES NOT eat paint, plastic, or rubber. Also, it is NOT a desiccant (does not pull moisture from the atmosphere) and "go bad" like the DOT4 in the brakes now. All the AN3 lines, seals and "O" rings are OK with DOT5. So is your paint.

Makes sense to me. DONE with "changing the fluids" every year, the bleeding trauma, etc. Low maintenance is the mantra of BMW, no??

AndyS,

A very thorough comparison of DOT4 and DOT5, along with the "compressibility" question are shown here:

http://www.buckeyetriumphs.org/technical/Brakes/Fluid/Fluid.htm

This article states:

These measurements and the calculations above demonstrate to me that the predictions of the dire consequences of using silicone fluid due to compressibility are overblown. I'm not surprised since both the US military and the US Postal Service use silicone fluid and, while I sometimes question some of the operational processes and procedures of both those organizations, I'm sure that both have sufficient data to expose any significant problem with the silicone fluid due to compressibility or anything else.

Hey, vindicated!! Who says this is a "dead horse"?? It's alive and kickin.

Vindicated, I concur with the "if you burst one hose, change the lot" philosophy. They're all the same age, the same construction, and have been through the same thing, so if one has burst the rest won't be far behind.

When mine went (long hose in the front wheel circuit) I just changed the lot, front and rear, with Spiegler parts. Took a little while to bleed, but job done.

As for fluid, if it was designed for DOT4 I'd stick with it. If it was designed for DOT5 then I'd stick with that. It's your machine and your choice.

I was getting the Excited Flashing Red Triangle of Imminent Doom on my dash. Before panicking, I decided to flush the entire brake system. While I was at it, I went ahead and put on a set of Speiglers. It wasn't that hard. Actually, the longest part of the process was actually bleeding the system. I used a cheap Mity-Vac knock-off, but ended up accidentally getting some fluid into it so it no longer works. Next time I do a brake flush, I'm going to get a set of SpeedBleeders. And like Lowndes says, the Speigler lines look amazing - I especially like the machined splitter block for the front lines. Of course you can't see it when all the body work is back on, but I know it's there.

So did my warning light go out? Yes. Yes it did. Of course, I only have 100mi on it since I did the service, so time will tell.

I had the front brakes seize on my RT a couple days ago. Same apparent cause (hose degradation blocking the return ports). 40 years of motorcycle riding and that is on my Mt. Rushmore of harrowing experiences, for sure. It’s got me second guessing whether I want to keep riding old bikes period (says the guy who not long ago  replaced the hydraulics in his 56 year old Volkswagen).

2 hours ago, Brian Scott said:

I had the front brakes seize on my RT a couple days ago. Same apparent cause (hose degradation blocking the return ports). 40 years of motorcycle riding and that is on my Mt. Rushmore of harrowing experiences, for sure. It’s got me second guessing whether I want to keep riding old bikes period (says the guy who not long ago  replaced the hydraulics in his 56 year old Volkswagen).

Brian,

I had the same experience several years back, locked up front wheel - see my post in this thread June 23, 2016.  There is a "wide place" in the hydraulic galleries between the caliper halves.  I had to split the calipers to clear the junk in that cavity.  I'm guessing BMW did this "wide place" to allow for variation in the hole alignment between caliper halves with these small diameter galleries.

While I had the front brakes apart, ALL the flexible hydraulic lines got replaced, front, rear, and clutch.  END of worry.  NO "brake issues" in any of my three 2000 era BMW's, all with "braided SS" hydraulic lines now.  Even the bleeder lines on the clutch slave cylinders got replaced.

This is the "wide place" that trapped the crud (after the cleanup):

This is the crud (in the hole above) on opening the caliper halves:

All of the pics here:  https://photos.app.goo.gl/kN8PyDxEirl9iVS02

Replace the lines and "drive it like you stole it".

SAFELY!!

Wow. Thank you sir! That was very nice of you to show me the photos and help clarify the issue. I really appreciate that. It sure was utterly harrowing huh! I have brand new Spiegler black stainless lines now, and even replaced the fuel fittings with metal too. Deteriorating rubber/plastic is inevitable over time, and it’s not worth losing one’s life over!