C-400GT braking problem

[GB Mike]

I've had my C400GT for almost three years and 16,000 miles. In that time I've mostly been unable to brake hard using the front brakes because it seemed dangerous. Front braking causes an extreme vibration that seems to threaten to become a death wobble. BMW has replaced the front discs twice because they were out of spec, the last time being at around 11,500 miles, and it's since started to vibrate again. Not sure why they can't figure out what's causing this and when I was debating buying an extended warranty they said they wouldn't guarantee that the extended warranty would cover this basic safety issue. They also said there were no service bulletins. I'm not sure how to proceed other than to have my estate sue BMW if it actually tosses me. I've been riding big & little bikes since 1964 and I really do like this bike other than the braking issue.
Anybody else have this issue with a BMW C400GT?

 

[wspollack]

I've had my C400GT for almost three years and 16,000 miles. In that time I've mostly been unable to brake hard using the front brakes because it seemed dangerous. Front braking causes an extreme vibration that seems to threaten to become a death wobble. BMW has replaced the front discs twice because they were out of spec, the last time being at around 11,500 miles, and it's since started to vibrate again. Not sure why they can't figure out what's causing this and when I was debating buying an extended warranty they said they wouldn't guarantee that the extended warranty would cover this basic safety issue. They also said there were no service bulletins. I'm not sure how to proceed other than to have my estate sue BMW if it actually tosses me. I've been riding big & little bikes since 1964 and I really do like this bike other than the braking issue.
Anybody else have this issue with a BMW C400GT?

1) No, I didn't have this issue on my '22 C 400 GT (had 5,000+ miles on it) and I don't have this issue on my '23 C 400 GT (have 6,000+ miles on it). And I brake pretty hard, on occasion (although typically squeezing both front and rear brakes), in some spirited riding.

And in two+ years of pretty faithful forum reading (and it's not as if the amount of posts here is overwhelming) I don't recall reading about such problems.

2) I would be surprised if this issue is not covered by BMW's extended warranty. As I understand it -- and I bought one for my former '22, and expect to buy one for my '23, before its three-year/36,000-mile warranty runs out -- everything that the initial warranty covers is covered by the extension.

(In case you were wondering, I had an engine problem on my '22, and after four months of the bike's being in the shop in the summer of '23, either corporate BMW or the dealership or a combination of the two eventually decided to replace the bike with a brand new '23.)

3) I haven't had any discs replaced, or anything like that done, and I've had the initial and 6K services done at my local BMW dealership (Max BMW, Troy, NY) on both scoots. I'm FAR from an expert on this sort of thing, but from reading forums over the years, I wonder:

- Have they loosened the fork pinch bolts, and bounced the forks, to get the front wheel in its comfortable position, and then re-tightened everything? Or, more generally, have they examined the forks for any quirks?

- Have they examined, and then possibly replaced, the brake pads?

- Have they examined the front rim, and checked it for balance and run-out?

- Have you been using the same tire brand all those miles? (I recently switched from Pirelli to Michelin, for example, but I haven't ridden since that switch in November.) More generally, have they checked the tires for proper balance, no manufacturing defects such as run-outs or other oddities?

That's all I got.

 

[sanoke]

I've had a similar problem on my 2019 C400X although not as extreme as yours sounds. I first thought it might be one of the discs was warped but when I checked the run out, both discs were in spec. What I did that seems to have fixed it is I started using mainly the front brake and lightly applying it coming to a stop when possible. Over time, that has worn in the rotors so that they no longer chatter when I apply the brake hard. My theory is that the machine marks left on the new rotors caused the problem and wearing them in over time has removed the machine marks.

 

[GB Mike]

1) No, I didn't have this issue on my '22 C 400 GT (had 5,000+ miles on it) and I don't have this issue on my '23 C 400 GT (have 6,000+ miles on it). And I brake pretty hard, on occasion (although typically squeezing both front and rear brakes), in some spirited riding.

And in two+ years of pretty faithful forum reading (and it's not as if the amount of posts here is overwhelming) I don't recall reading about such problems.

2) I would be surprised if this issue is not covered by BMW's extended warranty. As I understand it -- and I bought one for my former '22, and expect to buy one for my '23, before its three-year/36,000-mile warranty runs out -- everything that the initial warranty covers is covered by the extension.

(In case you were wondering, I had an engine problem on my '22, and after four months of the bike's being in the shop in the summer of '23, either corporate BMW or the dealership or a combination of the two eventually decided to replace the bike with a brand new '23.)

3) I haven't had any discs replaced, or anything like that done, and I've had the initial and 6K services done at my local BMW dealership (Max BMW, Troy, NY) on both scoots. I'm FAR from an expert on this sort of thing, but from reading forums over the years, I wonder:

- Have they loosened the fork pinch bolts, and bounced the forks, to get the front wheel in its comfortable position, and then re-tightened everything? Or, more generally, have they examined the forks for any quirks?

- Have they examined, and then possibly replaced, the brake pads?

- Have they examined the front rim, and checked it for balance and run-out?

- Have you been using the same tire brand all those miles? (I recently switched from Pirelli to Michelin, for example, but I haven't ridden since that switch in November.) More generally, have they checked the tires for proper balance, no manufacturing defects such as run-outs or other oddities?

That's all I got.

Thanks for the reply. I did have the front tire replaced at 12K. It didn't show any odd wear patterns or cupping & never did feel like it was vibrating, but it seemed logical that something in the wheel was causing the problem. They said they put the tire on a stand & checked it to see if the rim was true & didn't find anything. The front forks aren't leaking & braking doesn't seem to cause any diving as will sometimes happen if, for example, one of the forks is leaking oil. Again, they replaced both discs twice but only also replaced the pads the first time. I'm thinking of getting one of those wheel rollers for cleaning the front wheel to see if I can see any warping in the rim but presumably that was checked when they had the wheel off. At one point they suggested (see reply by sanoke above) that I wasn't using the proper braking technique - too light I believe was their theory. I noted that I'd had bikes with hydraulic discs since 1971 and hadn't had the problem previously, but I tried using the front brake a little harder than usual. Didn't help & the problem seems to be reoccurring so I'm sort of stuck using mostly the back brake now if possible.

Speaking of engine issues, and on a completely different topic, on 10/25/23 I was doing 70 on I-43 when the engine stopped & the dash flashed 'Serious engine control module fault. Further Journey possible. Engine damage possible. Have engine checked by service department'. I'm all for the bike protecting the engine but I'm not sure BMW thought this one through because without a clutch it's impossible to re-start the bike until you stop & put the brake on & I was just going over a bridge at the time. (I would actually prefer that the safety system protected me rather than the engine if it came to a choice.) I did manage to get out of traffic & stopped by the side of the road & after a bit I restarted & drove it home slowly. I took it to BMW & they said they could see that something had happened but couldn't determine what it was. They kept it for quite a while & I believe did one computer update that they didn't think was connected to that issue, but they never did figure out why it did that. That was around 5,000 miles ago and it's never happened again. Again BMW said there were no service bulletins on that topic either.

In case anybody's wondering why I don't just get rid of this bike, a. I like it a lot - it's comfortable & fun, and b: I broke my left leg in two places a couple of years ago & can't really shift with the left leg (I broke it in a very manly fashion - I fell off my 3-year-old grandson's toy snowboard in the back yard), not to mention that getting one leg over a big bike doesn't get easier in your mid-70s.

Anyway, thanks for the replies & keep the shiny side up.

Mike

 

[wspollack]

Thanks for the reply. I did have the front tire replaced at 12K. It didn't show any odd wear patterns or cupping & never did feel like it was vibrating, but it seemed logical that something in the wheel was causing the problem. They said they put the tire on a stand & checked it to see if the rim was true & didn't find anything. The front forks aren't leaking & braking doesn't seem to cause any diving as will sometimes happen if, for example, one of the forks is leaking oil. Again, they replaced both discs twice but only also replaced the pads the first time. I'm thinking of getting one of those wheel rollers for cleaning the front wheel to see if I can see any warping in the rim but presumably that was checked when they had the wheel off. At one point they suggested (see reply by sanoke above) that I wasn't using the proper braking technique - too light I believe was their theory. I noted that I'd had bikes with hydraulic discs since 1971 and hadn't had the problem previously, but I tried using the front brake a little harder than usual. Didn't help & the problem seems to be reoccurring so I'm sort of stuck using mostly the back brake now if possible.

Speaking of engine issues, and on a completely different topic, on 10/25/23 I was doing 70 on I-43 when the engine stopped & the dash flashed 'Serious engine control module fault. Further Journey possible. Engine damage possible. Have engine checked by service department'. I'm all for the bike protecting the engine but I'm not sure BMW thought this one through because without a clutch it's impossible to re-start the bike until you stop & put the brake on & I was just going over a bridge at the time. (I would actually prefer that the safety system protected me rather than the engine if it came to a choice.) I did manage to get out of traffic & stopped by the side of the road & after a bit I restarted & drove it home slowly. I took it to BMW & they said they could see that something had happened but couldn't determine what it was. They kept it for quite a while & I believe did one computer update that they didn't think was connected to that issue, but they never did figure out why it did that. That was around 5,000 miles ago and it's never happened again. Again BMW said there were no service bulletins on that topic either.

In case anybody's wondering why I don't just get rid of this bike, a. I like it a lot - it's comfortable & fun, and b: I broke my left leg in two places a couple of years ago & can't really shift with the left leg (I broke it in a very manly fashion - I fell off my 3-year-old grandson's toy snowboard in the back yard), not to mention that getting one leg over a big bike doesn't get easier in your mid-70s.

Anyway, thanks for the replies & keep the shiny side up.

Mike

1) Sorry to hear that none of the potential fixes has worked or are relevant to your braking problem.

2) I bought the Harbor Freight wheel gizmo a couple of years ago:

Motorcycle Wheel Cleaning Stand

Amazing deals on this Motorcycle Wheel Cleaning Stand at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

I wanted an easier way to rotate the front wheel, to get a better grasp, and do some measuring, regarding the problem of not being able to mount an external TPMS sensor on the front wheel (I have a FOBO sensor on the back wheel).

However, I don't think that's an appropriate device for checking runout or any other fine-grain wheel checking. For that, I believe you'd need a fork- or axle-mounted chock, such that the wheel can spin completely freely.

On the other hand, that HF chock is a pretty nice aid when you want to get the front wheel squeaky clean, which I do once or twice a year. You put it behind the front wheel, and then swing the bike onto the centerstand, as usual.

3) I described my engine failure -- it lost 20% or more of its power during one day trip -- and the response of corporate and the local dealership in agonizing detail in a lengthy post here a year and a half ago:

Thread 'BMW Swapped Out My Used '22 C 400 GT For A Brand New '23 C 400 GT ... Free. [Part I of II]'

Oct 19, 2023

Today, My Used 2022 C 400 GT Was Replaced By BMW With A Brand New 2023 C 400 GT. Free. What's In Your Warranty?

If those statements pique your curiosity, and you have some free time, here's the tale, in chronological order. Note that it starts LAST year, almost a year and a half ago.

[Note: some email and phone summaries have been omitted for brevity.]

05/23/2022: I call MAX BMW's Troy, NY, location, give my credit-card info for a deposit, and order a new C 400 GT. MAX is a large BMW motorcycle dealership, with two additional locations in CT and another one in NH.
...

• wspollack
• Replies: 11
• Forum: C400X - C400GT General Discussion

• 

I made the post extremely long, so any readers could get a sense of the time frame involved. The good news, besides eventually getting a new C 400 GT, was that I bought a new Royal Enfield Meteor 350 while the Beemer was spending the summer in the shop, and -- riding seasons permitting -- I have enjoyed that old-timey bike ever since.

 

[LEAKINGLEWIS]

Thanks for the reply. I did have the front tire replaced at 12K. It didn't show any odd wear patterns or cupping & never did feel like it was vibrating, but it seemed logical that something in the wheel was causing the problem. They said they put the tire on a stand & checked it to see if the rim was true & didn't find anything. The front forks aren't leaking & braking doesn't seem to cause any diving as will sometimes happen if, for example, one of the forks is leaking oil. Again, they replaced both discs twice but only also replaced the pads the first time. I'm thinking of getting one of those wheel rollers for cleaning the front wheel to see if I can see any warping in the rim but presumably that was checked when they had the wheel off. At one point they suggested (see reply by sanoke above) that I wasn't using the proper braking technique - too light I believe was their theory. I noted that I'd had bikes with hydraulic discs since 1971 and hadn't had the problem previously, but I tried using the front brake a little harder than usual. Didn't help & the problem seems to be reoccurring so I'm sort of stuck using mostly the back brake now if possible.

Speaking of engine issues, and on a completely different topic, on 10/25/23 I was doing 70 on I-43 when the engine stopped & the dash flashed 'Serious engine control module fault. Further Journey possible. Engine damage possible. Have engine checked by service department'. I'm all for the bike protecting the engine but I'm not sure BMW thought this one through because without a clutch it's impossible to re-start the bike until you stop & put the brake on & I was just going over a bridge at the time. (I would actually prefer that the safety system protected me rather than the engine if it came to a choice.) I did manage to get out of traffic & stopped by the side of the road & after a bit I restarted & drove it home slowly. I took it to BMW & they said they could see that something had happened but couldn't determine what it was. They kept it for quite a while & I believe did one computer update that they didn't think was connected to that issue, but they never did figure out why it did that. That was around 5,000 miles ago and it's never happened again. Again BMW said there were no service bulletins on that topic either.

In case anybody's wondering why I don't just get rid of this bike, a. I like it a lot - it's comfortable & fun, and b: I broke my left leg in two places a couple of years ago & can't really shift with the left leg (I broke it in a very manly fashion - I fell off my 3-year-old grandson's toy snowboard in the back yard), not to mention that getting one leg over a big bike doesn't get easier in your mid-70s.

Anyway, thanks for the replies & keep the shiny side up.

Mike

That's kind of scary that your engine stopped on a bridge. That could put someone in a perilous position. I don't know what I'd do if that happened on the Bay Bridge as there is no emergency lane. I've noticed that people have posted about getting the same message on an S1000 and a K1600. Some responses say it's related to moisture and usually doesn't occur after a software update. Watch out for those snowboards!