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Post by oldchopperguy on Mar 8, 2013 3:29:29 GMT -5
Hey riders,
In a previous post, I spoke of changing out factory tire valve-stems. Well, I did the front one fine, and went to lock the rear wheel by placing a rubber-band on the left brake handle as I did with the front. (Both my brakes are hydraulic disks).
I gave a squeeze on the left brake lever, and it began to compress. Then, the handle went over a slight "bump" and went clear to the handlebar with virtually NO braking on the rear disk.
I figured there was air in the line, or a leak... I pulled the plastics and removed the brake-cylinder reservior top expecting to see it low. Nope. Full-up and clean. NO leaks from cylinder to caliper, NO obvious problems anywhere at all.
I couldn't even bleed the brake caliper, since no pressure. The lever just goes over that "bump" and then loosely to the handlebar.
Something in the cylinder broke, or went south, and/or the fluid is passing by the piston. I am SO glad that happened in the driveway, NOT while roaring up on stopped traffic!!!
I have a new cylinder ordered. It will be here in a week or so. I have not done this replacement before, but I assume I can remove the brake line from the old cylinder, attach it to the new one, fill the new one and then bleed and re-fill to complete the job. I'll push out all the old fluid in the lines so it's all new juice.
If I'm wrong, somebody please let me know...
I'm posting this info for all to see, because if this DID happen while making a short stop, you'd be eating bumper... NOT good.
Of all the miriad of problems associated with Chinese scooters, I've never heard of THIS particularly dangerous issue. I truly hope it's not common!
Looking back, the ONLY warning I ever had was a very slight "wonky" feel in the brake lever during the last month when first beginning a ride. I thought it was just something because of the scooter sitting for a while. As soon as I used the brake a few times, it felt normal and worked fine... UNTIL that day that I applied it to work on the tire!
My advice: If you feel ANYTHING unusual with your hydraulic brakes, even ever so slight, check them out carefully, and see if you can find anything suspicious... It could save your life!
Ride safe!
Leo in Texas
PS: Please disregard all my bragging in other posts about how reliable my scoot has been for 5 years... THIS is not just an "inconvenience"... It's REALLY dangerous, and I'm not a happy camper... LOL!
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Post by terrilee on Mar 8, 2013 8:25:06 GMT -5
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Post by alleyoop on Mar 8, 2013 14:39:49 GMT -5
It could just be the rubber O-Rings Seals on the plunger Rod Check the Window on the Reservoir and notice the fluid level. When you start pressing it it should drop some. if after the bump it comes back up then it is probably just the seals on the plunger one of the is leaking and cannot take the pressure.
Alleyoop
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Post by prodigit on Mar 8, 2013 15:27:11 GMT -5
Crashing would really suck, however, another great reminder, always to ride defensively, and as safe as possible.
Even with one brake down, is no guarantee you'll be eating bumper. You could still engine brake, and use the other brake. For this very reason, I'm against a shared braking system of front and rear caliper.
You could also avoid the obstacle, and get around it.
Brakes are perhaps the most single important thing on a scooter, but it still is part of a series of procedures, that has a secondary and third backup in case something goes wrong.
And yet another wonderful reminder, of how important safety gear is!
You may be the world's best rider, and you may anticipate all traffic movements perfectly, but there's not a lot of tolerance for mechanical failure.
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Post by oldchopperguy on Mar 8, 2013 16:10:37 GMT -5
It could just be the rubber O-Rings Seals on the plunger Rod Check the Window on the Reservoir and notice the fluid level. When you start pressing it it should drop some. if after the bump it comes back up then it is probably just the seals on the plunger one of the is leaking and cannot take the pressure. Alleyoop I'm not familiar with these brakes (all my "old-school" rides had mechanical brakes... LOL!) but what you say makes perfect sense. In this case though, I'd rather spend a few bucks on a new cylinder, because the "offending" one is REALLY poor to begin with. I've never before removed the plastics to access the brake-lever areas, and while the front (right) assembly is clean, proper and looks like good quality, the rear (left) assembly is just AWFUL. It's covered with corrosion and that unidentifiable "Chinese metal fungus..." (even INSIDE the reservoir) and has surface cracks, and the entire casting looks like something dug out of a Chinese dumpster... Probably WAS...Sadly, that kind of quality (or lack of...) is what gives these otherwise great little scoots their poor reputation. I'll bet you're absolutely right about the O-rings, and, I'll bet they're bad because of abrasion from rough corrosion in the cylinder wall.I found a California distributor on eBay with a complete new assembly (cylinder, lever and stoplight switch) for forty bucks delivered, and if there's a problem, I'm dealing with a good-rep AMERICAN business. The original stoplight switch works, but it's all corroded, and the chrome is peeling off the lever, which cuts the bejeebers out of my fingers... So affordable replacement of the entire assembly is mighty appealing to me.Normally I'm for the cheapest workable fix, but with the brakes, ESPECIALLY after finding the original part to be SO rough, I'll skip a couple of trips to IHOP (well, maybe 3 or 4 senior meals...) and replace with new... I just feel better that way. Fixing the original would really be just delaying another failure on this assembly (which MUST have been dug out of a reject-bin).Thanks SO much for your advice! I had no idea you could rebuild the innards of the cylinder unit. I'm always wanting to learn. My 1960's big-bike history means nothing with these new scooters...Sincerely, Leo |
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Post by oldchopperguy on Mar 8, 2013 16:27:23 GMT -5
Crashing would really suck, however, another great reminder, always to ride defensively, and as safe as possible. Even with one brake down, is no guarantee you'll be eating bumper. You could still engine brake, and use the other brake. For this very reason, I'm against a shared braking system of front and rear caliper. You could also avoid the obstacle, and get around it. Brakes are perhaps the most single important thing on a scooter, but it still is part of a series of procedures, that has a secondary and third backup in case something goes wrong. And yet another wonderful reminder, of how important safety gear is! You may be the world's best rider, and you may anticipate all traffic movements perfectly, but there's not a lot of tolerance for mechanical failure. Being very light, and having major engine-braking (I seldom need to even use my brakes normally when coming to a redlight, until down to "walking" speed) a failure of either brake on these scoots wouldn't be a problem in anything but a panic stop situation. I ride VERY defensively in my old age... LOL! But it just bugged me that this happened. The offending brake cylinder assembly is absolutely AWFUL. I know better than to expect "Vespa quality" from a $700 scooter... But the front brake assembly is just fine, while the rear brake assembly truly looks like it came out of a junk-pile that sat outdoors in the weather for a few years. I'm sure Alleyoop has the answer, with the internal O-rings being bad. And, I'll bet the farm they went bad because the cylinder wall is corroded and rough. Poor quality parts that "won't make it go" are an irritation, but poor quality parts that "won't make it stop" are a major bite... It's to be expected on these, but it still bugs me... Just old age I guess... LOL! Leo (riding defensively) in Texas... |
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Post by oldchopperguy on Mar 8, 2013 16:35:45 GMT -5
[/img] [/color][/quote] Terrilee,
Alleyoop has the answer. I'm sure he's right about the internal O-rings gone bad. I'm pretty sure that happened due to corrosion in the cylinder wall... The original part is just AWFUL. Lots of gremlins hiding under all that pretty plastic!
Watch out for them...Leo |
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Post by alleyoop on Mar 8, 2013 17:20:57 GMT -5
Yes you will be better and will have piece of mind and more assured of your safety with a new one on if it looks that bad, I would do the same instead of rebuilding it.
Alleyoop
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Post by terrilee on Mar 8, 2013 17:42:24 GMT -5
im glad my reservoir window is where i can see it
w/o taking tuperware off
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Post by oldchopperguy on Mar 8, 2013 22:33:07 GMT -5
im glad my reservoir window is where i can see it
w/o taking tuperware off
You are RIGHT about that! I have a full cup of those wonky Chinese sheetmetal screws, and plastics, instruments, etc. dangling against rags ALL OVER the scoot. Hope I can remember just how it all goes back together! It's enough to make a guy go "Ruckus" or "nekked-scoot"... LOL! After digging down to the bare bars, I may well cut LARGE access-holes in the plastic, over the brake cylinders... I can live with homemade covers painted to match, better than I can live with taking it all apart just to mess with fluids... And, taking it all apart compromises all the crummy plastic plugs and connections for the electrics. All the wires and cables are about an inch too short to work with... Cheesh! Those new Kymco 200's are looking better and better... And, the local dealer is a gun-enthusiast. I'm starting to think: "A couple of good AK-47's should be more than worth a $3,200 Kymco..." Could be a trade is in the offing. I can't spend any money, but I would use a new scooter a lot more than an assault rifle. I have enough firepower, but am short on transportation... LOLOLOL!Ride safe! Leo |
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Post by terrilee on Mar 8, 2013 22:38:08 GMT -5
leo
thats a fair trade.
the kymcos 200 are nice
but i LOVE the blur 220
& its american made.
but $$$$$$$$
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..BAD TO THE BONE..
