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Discussion Starter #1
Folks:

For what it may be worth, all of my sponginess, lever travel and pressure loss are now gone. Whether or not any of that returns remains to be seen. The solution? I had a new OEM 5/8 MC installed under warranty!

I experienced many of the issues that '05+ riders have been experiencing, but was usually able to manage the brakes by consistently squeezing and holding the lever to build up pressure. I had to do that more and more, even with a bleed and a caliper/piston cleaning. However, it got to the point where the lever was consistenly coming all the way back to the grip. But, the brakes did work.

Well, I had enough of that. I got on the horn with Triumph. Their initial claim was that all 06 STs were assembled with the 5/8 MC (this despite the fact that mine, assembled in 10/05, was clearly stamped as 14mm. By the way, I was looking at an '06 on a dealer's floor, assemled in 11/05, which had a 5/8 MC. Go figure?) Anyway, a tech agreed with me that under no circumstances should I ever be able to pull the lever all the way back to the grip.

Leaving out a couple of conversations, and a total pressure loss event, Triumph agreed to replace my MC. They then decided to only replace the innards of my existing MC, and proceeded to send the wrong parts, which interestingly enough, are labeled as the correct parts in Triumph's databas. Another mystery! On the second round, Triumph simply sent the whole 5/8 assembly.

All sponginess, excessive travel, low pressure, etc. symptoms are gone. The brakes are now strong and progressive. The only difference is that the 5/8 MC setup requires more hand pressure on the lever than the 14mm. Once I got accustomed to the different feel, no problem.

So, kudos to those who persevere with their mercurial brakes. For those who have not experienced these issues, you are fortunate. For those who have had enough, try a warranty claim, or go ahead and consider a MC change on your own. All I can say is that it has worked wonderfully on my '06.

Aaron
 

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I wondered why I had never seen these symptoms on my bike. Mine was built 08/05 and had the 5/8 MC from the factory. Go figure?

Jim T.
 

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How many miles have you rode since the change?

Triumph claims its just a bunch of internet boards whining about poor brakes. Mine is acting the same way you describe yours and it also has a 14mm m/c. I can take the calipers off and move the pistons in and out a couple times and they will be good for a few hundred miles.
The dealer says he wants to help but Triumph says there is no problem.

Mine was built 09/05

[ This message was edited by: 86gn on 2006-11-28 09:42 ]
 

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No 05 model year or 06 model year NON-ABS ST was manufactured with 5/8 MC's.

Some 06 ABS ST's were manufactured with 5/8 MC's.

Triumph will replace under warranty the 14mm MC's for the 5/8 MCs for the ABS bikes. I'm not so sure they will easily do that for the non-ABS bikes.

At least this is my knowledge and experience in dealing with the Greek distributor who got in contact with the factory in the UK in my presence. Triumph asked for the VIN of the bike to authorise the replacement.

I wonder if the 07 bikes are delivered with the 5/8 MCs. All of them? Just the ABS's?



[ This message was edited by: NikosR on 2006-11-28 09:59 ]
 

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Discussion Starter #5
86gn: I've ridden approximately 200 miles since the change. While this is no great distance or time, the big difference is that there is no pressure loss whatsoever. Prior to the change, I was experiencing pressure loss during any period when the brakes were not being used: overnight, during the day, even during a ride! Even after two piston cleanings and reseatings, and two bleedings, I still experienced this pressure loss. The brakes would work, but only if I constantly pumped, squeezed and held the brake lever to build pressure. That is now gone.

Will it last? Time will tell. But, so far, the brakes have a much different, much stronger "feel" with no pressure loss.

Aaron
 

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My 05 has the 14mm. After almost 12,000 miles I must be getting used to them. I'll check with the guys at the shop before I bring it in for the 12,000 mile check.
 

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On 2006-11-28 11:27, sprintamx wrote:
86gn: I've ridden approximately 200 miles since the change. While this is no great distance or time, the big difference is that there is no pressure loss whatsoever. Prior to the change, I was experiencing pressure loss during any period when the brakes were not being used: overnight, during the day, even during a ride! Even after two piston cleanings and reseatings, and two bleedings, I still experienced this pressure loss. The brakes would work, but only if I constantly pumped, squeezed and held the brake lever to build pressure. That is now gone.

Will it last? Time will tell. But, so far, the brakes have a much different, much stronger "feel" with no pressure loss.

Aaron
Good job. I made the same change, with a slightly different MC (16mm Brembo Radial) and after 1000 miles the brakes are still very strong and consistent, as they should have been from new.
 

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And how do you tell which size M/C is on the bike?
(I would have expected something on the cover but there is nothing there...)

John
 

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Look behind the MC body on the side facing the handlebar. There should be a 14mm or 5/8 sign. Just black on black raised letters. Easy to miss.

[ This message was edited by: NikosR on 2006-11-30 09:03 ]
 

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On 2006-11-29 11:55, sprintamx wrote:
On the right side of the steering column.
I know that everybody in this forum says that's the bike build date, but I've also heard that's just the frame manufacture date.

Who knows for sure?
 

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On 2006-11-30 09:23, Johnmala wrote:
Efharisto!
My pleasure. Do you know any more Greek?

Actually you might have a 4/8 there or 48 meaning 14mm (I think... for some reason). Some MCs are marked in metric others in inches. It's confusing.

So what do you have?

[ This message was edited by: NikosR on 2006-12-01 08:24 ]
 

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Niko,

Spoke it as a kid - still understand it pretty well...

My build date is Feb/06, I've got the ABS model but I may have the 14mm. Won't be able to tell for sure 'till I've had a good look tomorrow in daylight. (not enough light in the garage).

I've just recently ordered the TOR and when I take it in for the install and the tune, I'll ask them to upgrade to 5/8 if needed.

Thanks again for your help,

John
 
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