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-   -   Front brake took a break (https://www.superhawkforum.com/forums/technical-discussion-28/front-brake-took-break-13946/)

XLSR-VTR1 03-03-2008 09:06 AM

Front brake took a break
 
Hey I looked around for this but didnt see anything. Went to take the bike out last week and when I grabbed the brake lever, nada, nothin. Wouldnt pump up, was like there was no fluid in it. Tried bleeding and still nothing.
Was thinking of getting a master cylinder rebuild kit but have considered using a different master cylider all together (RC51 or ?... thoughts?

RickB 03-03-2008 09:50 AM

Before you condemn it try keeping the brake lever tied back to the grip overnight, I have used this method when I bled brakes on my bikes and just didn't seem to get a a good feel out of the lever - it does help get trapped air out. If that doesn't work it sounds like you will need to rebuild it or use another model of master cylinder.

XLSR-VTR1 03-03-2008 12:02 PM

I dont think strapping the lever back will help this one.. it has no lever pressure at all, zero, it wouldnt even pump fluid out of the caliper when I tried to bleed it. Strangest thing Ive seen.

What I am wondering is if using a different master cylinder like from an RC would improve the feel of the lever? which one works best? does it bolt right up and use the same ss brake lines i have? Ive never been impressed with the oem unit on this bike from the start and that was 50k miles ago. Thanks.

superbling 03-03-2008 01:21 PM

The m/c rebuild kit is around $40! And with your mileage, it's probably a good idea to rebuild the calipers too. For that combined price, you can pick up an entire f4i system cheaper (with some luck) on ebay and upgrade.

http://cgi.ebay.com/ebaymotors/02-Ho...spagenameZWDVW

http://cgi.ebay.com/ebaymotors/HONDA...spagenameZWDVW

XLSR-VTR1 03-03-2008 02:33 PM

ok so i didnt look hard enough I just found the mod page with all kinds of good info... oops.

Hawkrider 03-03-2008 04:38 PM

1 Attachment(s)
You really need to double check for leaks before you condemn the master cylinder. I've not heard of one going bad on the VTR yet. Soft, yes, but not completely shot as you describe.

About sometime around 2001 or so I was taking the ride out of my shed one chilly day. Grabbed the front brake lever and it got soft real quick. I discovered a leak at the master cylinder banjo. I went to tighten the bolt and just the act of putting the wrench on the bolt resulted in the pic below:

XLSR-VTR1 03-03-2008 04:59 PM

I will check again, the bike has been parked in the garage in the same spot for the last couple months, I found no leaks. I'll take it apart to investigate the cause. The brake has always been soft, tried ss lines, hh pads, multiple bleeds with different fluids. I have a TLR, couple dirt bikes and the SH brake has always been unimpressive. After reading the mod thread on upgrading the brake system it seems the way to go.

That pic is incredible, I'll take it apart to see but I bleed my brakes every spring.

nuhawk 03-03-2008 06:17 PM

I think it's MightyVac to the rescue. You have to drag the fluid through these systems to get them to pressurize.

TXSuperChicken and I did an overhaul on my clutch hydraulics this last weekend and it makes a huge difference in time spent to have the pump and a pal to help run the lever.

We had the system up to pressure with dot 3 in 15 minutes and had the dot 3 replaced with dot 5.1 in about another 5.

skokievtr 03-03-2008 07:36 PM


Originally Posted by Hawkrider (Post 154425)
You really need to double check for leaks before you condemn the master cylinder. I've not heard of one going bad on the VTR yet. Soft, yes, but not completely shot as you describe.

About sometime around 2001 or so I was taking the ride out of my shed one chilly day. Grabbed the front brake lever and it got soft real quick. I discovered a leak at the master cylinder banjo. I went to tighten the bolt and just the act of putting the wrench on the bolt resulted in the pic below:


Dam Greg? Not even at the threads (stress corrosion in the thread roots can cause fractures). Looks like a SS dbl banjo overtorqued or residual stress fracture pop.

JesseW. 03-03-2008 08:01 PM

i had a rear banjo bolt do the same thing hawkrider. i hadn't tighted it in the 2 years i had the bike at the time and i noticed the rear was soft and was leaking, so i went to tighten it and it fell off

Hawkrider 03-03-2008 09:29 PM

Well, this wasn't stainless or aluminum. Look at the color. Stainless should be more ductile too, with a larger grain structure, right? It looked like some kind of chromed brass or something. The fracture type was definitely brittle, not ductile. It was not overtorqued either. I truly think that the cause of the failure was brittle fracture due to temperature and low fracture toughness. There must have been a flaw somewhere in the metal that propagated due to increased tensile stress from the contraction of the material at low temperature. It was probably close to 0° at some point that week. The pic is old and I wish I could have taken better ones back then, but you can still see the stress concentration area in the bolt head.

XLSR-VTR1 03-04-2008 10:36 AM

Thanks,
I have my club meeting tonight so hope to take it apart tomorrow. I have a friend with a mighty vac and will try it, but the suggestion of upgrading the brakes to something all together better sounds good to me. :)

XLSR-VTR1 03-04-2008 10:37 AM

oh Ive na heard of the banjo bolt breaking like that either. Thats a new one too!

ksumech 03-04-2008 01:17 PM

Sound likes engineer talk to me.......I didn't think they made banjo bolts out of brass?

XLSR-VTR1 03-04-2008 01:26 PM


Originally Posted by ksumech (Post 154536)
Sound likes engineer talk to me.......I didn't think they made banjo bolts out of brass?

HA! Funny. I am an engineer but just civil... not structural mechanics... This is the technical discussion page though. lol

8541Hawk 03-04-2008 01:45 PM


Originally Posted by Hawkrider (Post 154476)
Well, this wasn't stainless or aluminum. Look at the color. Stainless should be more ductile too, with a larger grain structure, right? It looked like some kind of chromed brass or something. The fracture type was definitely brittle, not ductile. It was not overtorqued either. I truly think that the cause of the failure was brittle fracture due to temperature and low fracture toughness. There must have been a flaw somewhere in the metal that propagated due to increased tensile stress from the contraction of the material at low temperature. It was probably close to 0° at some point that week. The pic is old and I wish I could have taken better ones back then, but you can still see the stress concentration area in the bolt head.

I had one do that to me just a few months ago when I changed my master cyl. The thing just sheard at the point where the cross hole was drilled at and at a very low torque. It also appeared to be made out of brass. :shock:

JesseW. 03-04-2008 02:01 PM

+1 i'm a student mechanical engineer, makes since to me. i say upgrade the brakes. i love the gsxr 6 pots and master on mine

XLSR-VTR1 03-04-2008 02:16 PM


Originally Posted by JesseW. (Post 154543)
+1 i'm a student mechanical engineer, makes since to me. i say upgrade the brakes. i love the gsxr 6 pots and master on mine

Did you have to change from the VTR brake lines? I have SS lines id like to keep. I can get new levers I guess... maybe sell these ones... carbon fiber painted ebay specials were only 30 or 35 bucks....

skokievtr 03-04-2008 03:38 PM


Originally Posted by Hawkrider (Post 154476)
Well, this wasn't stainless or aluminum. Look at the color. Stainless should be more ductile too, with a larger grain structure, right? It looked like some kind of chromed brass or something. The fracture type was definitely brittle, not ductile. It was not overtorqued either. I truly think that the cause of the failure was brittle fracture due to temperature and low fracture toughness. There must have been a flaw somewhere in the metal that propagated due to increased tensile stress from the contraction of the material at low temperature. It was probably close to 0° at some point that week. The pic is old and I wish I could have taken better ones back then, but you can still see the stress concentration area in the bolt head.

I thought at first it was chromed steel but the color threw me; its always hard to tell from a pic. Did you check it with a magnet to see if it was steel, wierd if its brass? Who made it? Temperature could be a factor but there had to be residual strees and/or a flaw to start with if torque is not a factor. I've have used aluminum banjo bolts but not brass? HEL will not use aluminum fittings on the hoses or bolts though Russell and others do (see http://www.helusa.com/HEL_Performanc..._Aluminium.htm).

Whatever, I hope it never happens to me somehow.

Hawkrider 03-04-2008 04:48 PM

It was NOT ferrous. I checked, because when I saw the color of the material it piqued my curiosity. The part was an original Galfer part. They offered to send a new one after I sent them the pic. Needless to say I declined the offer. :roll: :noevil:

XLSR-VTR1 03-04-2008 04:55 PM

Interesting, these lines are Galfer. Now I really want to tear into it and see what going on, hope it doesnt sheer off too.

josj 03-04-2008 05:19 PM

I have the same problem with my original front brake master cylinder, it doesn´t have any preasure, I tried bleeding and still nothing so I bought a rebuilt front master cylinder kit, about 30 euros, and a new banjo. Now I am using a f4i master cylinder but I prefer the original, so when I can, I will star to change the rebuilt kit into the cylinder, does anyone know where can I found more information about it? Thanks very much.

XLSR-VTR1 03-04-2008 05:23 PM

well at least im not the only one... when you took the banjo bolts off was there sludge?

8541Hawk 03-04-2008 05:28 PM


Originally Posted by Hawkrider (Post 154562)
It was NOT ferrous. I checked, because when I saw the color of the material it piqued my curiosity. The part was an original Galfer part. They offered to send a new one after I sent them the pic. Needless to say I declined the offer. :roll: :noevil:

Maybe it's a Galfer thing because now that you mention it, that's what mine was also, the one that came in the kit with the lines...

josj 03-04-2008 05:33 PM

I´am sorry XLSR-VTR1 but my Engish is not very good and I don´t understand your question.
At first I was using a f4i master cylinder because my original one, was broken in an accident, so I bought another one and when I put it with a new banjo bolt, I bleeded the system and the master cylinder it had not any preausure, It was like the system didn´t have the dot 4 liquid, so I understood that the problem can be the wharf cylinder, that´s why I buy a rebuilt kit.

TwinSpeedJunkie 03-04-2008 06:03 PM

For what it's worth, I bought a brand new Nissin radial brake mastercylinder for my superchicken on E-Bay. It was a direct bolt-on application and is light years better than the stocker. I think that I still need some braided lines to go with it, but it was an huge improvement over stock. The only modification needed was a minor tweek to the resevoir mounting tab to make sure that the resevoir was properly situated. Even the stock brake line worked and bolted right up with no hassles.
The vender was awesome and had it shipped to me in just 3 days (their standard shipping through USPS).

Check here:
http://cgi.ebay.com/ebaymotors/ws/eB...2BSI%26otn%3D4

RCVTR 03-04-2008 06:12 PM

You said the lever was alwyas spongy?
I don't think you have a broken banjo bolt.
I think you had an air bubble in the brake line all along. the brake lever should feel firm when it's bled properly.

I would say you have an air bubble that finally burped into the master cylinder. That's good news, because it's easy to get rid of now.

there's an orifice that supplies brake fluid to the master cylinder from the reservoir. Take the M/C off and wire it up so the orifice is at the high spot, then press the slave pistons into the calipers. You should see the bubble come out of the orifice because the bubble floats.

Reassemble and pump the brakes back up, making sure you don't run out of fluid in the reservoir.

skokievtr 03-04-2008 08:25 PM


Originally Posted by Hawkrider (Post 154562)
It was NOT ferrous. I checked, because when I saw the color of the material it piqued my curiosity. The part was an original Galfer part. They offered to send a new one after I sent them the pic. Needless to say I declined the offer. :roll: :noevil:

Somebody should ask Galfer why they make their bolts out of sintered macadamia nuts?

skokievtr 03-04-2008 08:27 PM


Originally Posted by TwinSpeedJunkie (Post 154585)
For what it's worth, I bought a brand new Nissin radial brake mastercylinder for my superchicken on E-Bay. It was a direct bolt-on application and is light years better than the stocker. I think that I still need some braided lines to go with it, but it was an huge improvement over stock. The only modification needed was a minor tweek to the resevoir mounting tab to make sure that the resevoir was properly situated. Even the stock brake line worked and bolted right up with no hassles.
The vender was awesome and had it shipped to me in just 3 days (their standard shipping through USPS).

Check here:
http://cgi.ebay.com/ebaymotors/ws/eB...2BSI%26otn%3D4

Ouch! I luv how the Buy IT NOW Price is $160 and the Starting Bid is $159.99

ksumech 03-05-2008 05:11 AM

I'm a degreed mechanical. Has anyone ever tried Goodridge banjo bolts on the superhawks? I've had good experience with their lines and fittings on American V-Twins.

TwinSpeedJunkie 03-05-2008 05:44 AM


Originally Posted by skokievtr (Post 154612)
Ouch! I luv how the Buy IT NOW Price is $160 and the Starting Bid is $159.99

A lot of E-Bay venders do that, so it's no biggie to me.
As far as the price goes ... I'm satisfied. I have a brand new part with a warranty, it shipped uber fast, and it bolted on without any modifications to any of the standard mounting areas or lines. I am sure that I could have bought a low-line Brembo for about another $100.00 more, but then I would have had to finagle with lines, a resevoir, a brake light switch and ... :rolleyes:

Does anyone know where to buy Spiegler brake line kits at a reasonable price?

skokievtr 03-05-2008 06:50 AM


Originally Posted by ksumech (Post 154627)
I'm a degreed mechanical. Has anyone ever tried Goodridge banjo bolts on the superhawks? I've had good experience with their lines and fittings on American V-Twins.

degreed - Geometry. the 360th part of a complete angle or turn, often represented by the sign°, as in 45°, which is read as 45 degrees. Compare angle. mechanical - Operated or produced by a mechanism or machine

I'm sorry for you, and yes.

JesseW. 03-05-2008 08:09 AM

come to think about it i have galfer ss lines on mine too, maybe its a galfer problem instead of a honda problem

lines should bolt right up. they did on mine.

ksumech 03-05-2008 09:58 AM


Originally Posted by skokievtr (Post 154632)
degreed - Geometry. the 360th part of a complete angle or turn, often represented by the sign°, as in 45°, which is read as 45 degrees. Compare angle. mechanical - Operated or produced by a mechanism or machine

I'm sorry for you, and yes.

It gets better, my wife has a math degree:shock:

XLSR-VTR1 03-05-2008 10:09 AM

Si senorita! gotcha. My espanol es muy pocito. I understand, yours was broken.

Wow, this is has gotten very interesting.. Thanks for the added advise for checking for air bubbles, and that radial mc looks cool but kinda spendy.

Back to algebra class you two! :)

XLSR-VTR1 03-05-2008 10:18 AM


Originally Posted by RCVTR (Post 154587)
You said the lever was alwyas spongy?
I don't think you have a broken banjo bolt.
I think you had an air bubble in the brake line all along. the brake lever should feel firm when it's bled properly.

I would say you have an air bubble that finally burped into the master cylinder. That's good news, because it's easy to get rid of now.

there's an orifice that supplies brake fluid to the master cylinder from the reservoir. Take the M/C off and wire it up so the orifice is at the high spot, then press the slave pistons into the calipers. You should see the bubble come out of the orifice because the bubble floats.

Reassemble and pump the brakes back up, making sure you don't run out of fluid in the reservoir.

So would you depress one caliper or both? do you disconnect the reservoir from the mc?
Ive been swamped with my club and work but tonight I'll be on it. I will try this first, then take apart the banjo fittings to see what it looks like.
Thanks again for that advise. When I replace my brake pads I always open the bleed screw on the caliper so I dont force old fluid back up into the mc. I suspect I dont have to depress the caliper piston very much right?

Hotbrakes 03-05-2008 01:41 PM

I think you probably need to bleed the banjo bolt. Reaper and I had trouble getting pressure to build up when he switched to a full RC-51 system. We kept milking fluid out of the bleed valves but never got any pressure. Called a mechanic and he said squeeze the lever and at the same time loosen the banjo bolt slightly. (wrap a towel around it) Then tighten it back down before you release the lever. No problems after that, lever pressurized immediately.

RCVTR 03-05-2008 04:17 PM

I had Goodridge lines and banjos. Good stuff.

XLSR-VTR1 03-05-2008 06:56 PM

Ok, I did the easy step. Ive bled my brakes for years, didnt run the reservoir empty, soo when i cracked the banjo loose and gave it a squeeze it blew bubbles not only once but half a dozen times. like the entire mc was full of air. weird thing is there was no fluid anywhere on the bike or the floor, so Im still perplexed on this, brake worked fine in November, sat and then this. can the washers on the banjo's go bad? The bolt was tight. I didnt take it off all the way but maybe I should. Anyway, I think I'll still keep my eyes open for a F4i, gixer, RC setup once I decide what setup I want.
I'll leave the lever alone for the night and check it again in the morning.

XLSR-VTR1 03-05-2008 07:00 PM

Oh, can a piston go bad and have a loss of fluid? but there would still be fluid somewhere visible...?


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