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Scooters - 125 to 300 => Grandvista 250 => Topic started by: griffon_j9 on November 09, 2009, 02:59:43 AM

Title: rear breaks on my GV bad?
Post by: griffon_j9 on November 09, 2009, 02:59:43 AM
Hello

Went riding today (perhaps for last time this year before snow?) any way The rear break system does not seem to be working well at all.  when I pull the handle it goes almost all the way to the grip and just barely stops the bike (lucky the front is working fine) 

Has any one had this problem and fixed it there selves????

let me know.... thinking about trying it myself.... but being as it is breaks... not sure I want to mess with it

easy project or hard???

later and thanks
Alan
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 09, 2009, 03:10:46 AM
My P250 has just started exhibiting the same behavior. I'm assuming it's the rear brake pads, as I'm at nearly 13,000km. Have the pads on order, and will have a mechanic friend at the co-op walk me through the process.
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Title: Re: rear breaks on my GV bad?
Post by: zombie on November 09, 2009, 08:28:02 AM
On a 1-10 scale brakes are about 3. There are register marks on the activator lever (rear) and the install is pretty straight forward. You may only need to adjust the cable to compensate for the stretch, and the wear of the pads. Go to the rear end of the cable, and there is a barrel nut that you can give 2-3 turns clockwise to remove the slack from the cable. You will see the register on the brake hub, and it will have a usable span marked clearly. If you are outside the limit, it's on to plan b. The muffler has to be removed to remove the wheel. That is the BIGGEST part of the brake job. I ALWAYS use 120 grit sandpaper to remove the "glaze' from the drum, and lube all moving parts w/ aluminum anti sieze. For a mechanic it is about a 1 hour job. For a first timer about2-3.
Title: Re: rear breaks on my GV bad?
Post by: axy on November 09, 2009, 10:21:52 AM
My P250 has just started exhibiting the same behavior. I'm assuming it's the rear brake pads, as I'm at nearly 13,000km. Have the pads on order, and will have a mechanic friend at the co-op walk me through the process.
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With symptoms like "the handle it goes almost all the way to the grip and just barely stops the bike", I would first look for oil leaks and air in the system.

I doubt that after "only" 13.000 kms rear pads are dead, unless somebody has been driving the scooter like on a race track.

p.s. On Piaggio NRG 50, front and rear pads last max 4500 km! :)
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 09, 2009, 05:18:21 PM
Well, funny you should mention (http://kymcojones.blogspot.com/2009/10/draggin.html)...  :)

(btw, I was using American decimal notation, e.g. thirteen thousand kilometers, or thirteen megameters, if you will... not sure if that got lost in the translation)
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Title: Re: rear breaks on my GV bad?
Post by: axy on November 09, 2009, 06:46:02 PM
Well, funny you should mention (http://kymcojones.blogspot.com/2009/10/draggin.html)...  :)

(btw, I was using American decimal notation, e.g. thirteen thousand kilometers, or thirteen megameters, if you will... not sure if that got lost in the translation)
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Yep, 13K. Well understood.

A friend of mine has Cobra 50, original front and rear pads and belt. :) 25K km. :)
Title: Re: rear breaks on my GV bad?
Post by: zombie on November 09, 2009, 08:40:06 PM
My bads on the brake adjust I was assuming it was a cable/ drum set up. Grand Vista aahhh. Follow axy's recomend. The fluid will break down over time, and needs to be changed just like any other fluid in the scoot. To replace the pads just became a 2 on the 1-10 scale. The fluid can be gravity bled.  If your fluid is a DARK color (yellow - brown) it just may be it has broken down. It should be clean/ and clear
Title: Re: rear breaks on my GV bad?
Post by: griffon_j9 on November 09, 2009, 11:46:08 PM
hi for all the info...

here is one for ya, it only has 3200 km (2000 miles) on it......

the fluids look clear and clean and I see no bubbles in the looking glass. I have not looked at the pads yet as I am not willing to get dirty tonight (maybe tomorrow while still in work clothes)

thanks for the pointers, I will keep looking.... little scared to mess with breaks though... even if they are simple
Title: Re: rear breaks on my GV bad?
Post by: reticulum on November 10, 2009, 04:05:19 PM
If I had to guess I would say you have air in the braking line. You can easily check you rear pads on the grand vista by removing the plastic cover on the rear caliper. It allows you to see the wear of your pads. It is is more dificult for the front break.
I will first bleed the break fluid and if it does not fix the problem...change the pads and look for any oil or grease on the disc.

I change my brake pads every year on my grand vista (every 4 to 6K miles). It is very easy to do it yourself. You just have to remove 2 screws....remove the caliper from the discs.....remove the 2 pads......push back the piston.....install the new pads......put back the caliper on the disk and reinstall the 2 screws...you are done. 15 minutes and $25 for the pads.
Title: Re: rear breaks on my GV bad?
Post by: Urbestfriend on November 10, 2009, 09:28:46 PM
Urbestfriend asks if here was a possibilty your bike may have fell over sideways and you
fortunately picked it back up,  OR:  If you remove the caliper and then push the pads back in to reinstall
it on the rotor,  you may have no pressure on the first cycle.   My first point is backed up by
my experience removing my handlebars and letting the master cylinder hang.  This let air in and
I had to bleed.   If you can afford it,  look at Harbor Freight or Sears for a Pressure Bleeder.
It's a little vacuum hand pump with a variety of fittings.  With low miles,  one would not expect
somethin like this,  unless a seal has blow-by in the Master Cylinder. 
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 11, 2009, 07:24:36 PM
My bads on the brake adjust I was assuming it was a cable/ drum set up. Grand Vista aahhh. Follow axy's recomend. The fluid will break down over time, and needs to be changed just like any other fluid in the scoot. To replace the pads just became a 2 on the 1-10 scale. The fluid can be gravity bled.  If your fluid is a DARK color (yellow - brown) it just may be it has broken down. It should be clean/ and clear
I opened the master cylinder, since I couldn't really tell the level through the peep hole. It was full, but the fluid was about the color of apple juice. I took it to my scooter dealer, and he recommended that we let his mechanic deal with draining/refilling the fluid -- he himself doesn't have a lot of experience with brakes. I still have the pads on order, though, just in case. They have to be worn out sometime!

Gravity bled: Interesting, as the valve is on top of my caliper... the dealer said he's got some kind of vacuum attachment that will completely bleed the system of fluid, but that it was a pain to use.

Any of that make sense? 
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Title: Re: rear breaks on my GV bad?
Post by: Shaka on November 11, 2009, 08:03:30 PM
The brakes are fairly easy to bleed!  All you need is some tubing that fits snugly over the bleed fitting on the caliper and a catch bottle.  They sell one pre-made at the auto parts store, I think it's called a one-manned bleed kit.  You just attach the hose and bottle to the fitting. . . Take the reservoir cap off. . . fill up the reservoir with fluid. . . loosen the bleed fitting about 1/4-1/2 turn. . . squeeze the brake lever. . . while still holding the lever. . . close the fitting. . . repeat until the fluid runs clear.  The trick is to make sure to keep the reservoir full, and close the fitting each time before releasing the lever, you don't want to suck in any air!
Title: Re: rear breaks on my GV bad?
Post by: zombie on November 11, 2009, 08:13:05 PM
When you are gravity bleeding you have to keep the resevoir topped of w/ clean fluid. It will allow all the fluid in the system to get replaced. I use a piece of clear tubing that fits on the bleed nipple. that will go into a clear jar on the floor. Just open the resevoir,and squeeze the handle. it will only take about 5 minutes from start to finish. The nipple is on the top of the caliper so any air in the system can easily be bled out. If you get overzealous w/ the vacuum bleeder the turbulence of the fluid rushing through will make micro bubbles that will create trouble later. As urbestfriend stated the only other suspect would be a faulty seal inside the master cyl.. They do go bad from time to time. If the fluid, and pads are serviceable, the cyl. is the culprit.
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 11, 2009, 11:44:04 PM
Sounds like a two-person job for the rear brake, anyway (which is what I'm dealing with, here).  :)
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Title: Re: rear breaks on my GV bad?
Post by: Shaka on November 12, 2009, 02:04:38 AM
Yup, probably easier with two people on rear! ;)
Title: Re: rear breaks on my GV bad?
Post by: zombie on November 12, 2009, 06:54:29 AM
I think we posted at the same time...
Title: Re: rear breaks on my GV bad?
Post by: reticulum on November 12, 2009, 03:04:16 PM
Jprestonian, We can do it together if you want (Just stop by one evening). I usually ask my wife to help me for the rear brake bleeding.
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 12, 2009, 08:29:31 PM
Thanks, reticulum!  Actually, since I had to work at the shop today, Josh showed me how easy it is to do by myself (open master cylinder, pump brake, SLOWLY open bleeder valve to let fluid and any air escape, being sure NOT to suck air back into the bleeder valve, re-tighten bleeder valve, and repeat several times, adding fluid at the master cylinder as needed). After less than 30 minutes, my rear brake is back to its formerly awesome condition.  :)
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Title: Re: rear breaks on my GV bad?
Post by: Shaka on November 12, 2009, 08:35:08 PM
Awesome!  And now you know how easy it is to do it yourself! ;)
Title: Re: rear breaks on my GV bad?
Post by: zombie on November 13, 2009, 12:28:23 AM
Thanks for looking out for EVERYONE jpres. I like your taste in music as well! Have you heard Rocco De'Luca \, and the Burden. Awesome cruising music!!!
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 13, 2009, 01:30:06 AM
Hey, just tryin' to share the wealth, as it were.  :)  I haven't heard Rocco De'Luca... where did I talk about music, btw? 
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Title: Re: rear breaks on my GV bad?
Post by: zombie on November 13, 2009, 04:03:44 AM
Your VID. The N.C. Crusi'n. The music you put to the expedited VID was like a roller coaster ride. TTTOOO much respect for how much fun I had watching it. A few times I thought it was going to go bad. Just too ccccccooooolllll! I am not too savvy w/ the computer, but it is posts like yours that gives the inspiration to learn. I am still learning how to use "spell check".
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 13, 2009, 05:51:28 AM
Oh!  Well, I used YouTube's "audio swap" feature for that -- I have to click the "more info" link on the video @ YouTube to even recall the name of the band.  :)  All the music found there is royalty-free. I would prefer to edit in clips (which I have lovingly edited to-length, and faded on both ends)  of music from my legally-purchased collection of tunes, but if you look through my YouTube collection, you'll find a LOT of my videos don't have ANY audio... 'cause the record labels don't want me promoting their artists.  ;)
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Title: Re: rear breaks on my GV bad?
Post by: griffon_j9 on November 23, 2009, 02:00:52 AM
Hey everyone,

Sorry for the long in between pause there, I read all the post and decided to try the whole bleeding the breaks thing myself.... well it was messy as the tub would not stay in the bleeder valve very well... but I think it worked! they tightened up nice (not perfect but almost the same as the fronts now) But I have to buy some break cleaner before I try it as it leaked all over X_x;;;

anyway thanks! and I will let you know more once I get it cleaned ^_^
Title: Re: rear breaks on my GV bad?
Post by: Shaka on November 23, 2009, 03:55:48 AM
You can use rubbing alcohol to clean up the brake fluid if you don't have any brake cleaner handy.  Make sure you clean any that leaked off as it is extremely corrosive!  I usually use a spring wound around the outside of the bleed tube at the end.  This helps hold the hose onto the bleed nipple.  You can use the spring out of a ball point pen if you open up the coils wider to fit around the tube.  Maybe a helpful tip for next time! Glad you got it worked out though!
Title: Re: rear breaks on my GV bad?
Post by: jprestonian on November 23, 2009, 04:27:17 AM
Carb/choke cleaner also works pretty well.
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Title: Re: rear breaks on my GV bad?
Post by: Rudolf on October 04, 2012, 01:59:04 PM
My bike's rear disc brake is worn thin, it's around 2mm thin or less in some areas of the disc. The rear brake is working fine, for now....