master cylinder beast
 

My rear brakes have gone to mush. No stopping power at all. I have bled the the brake and although the bleed nipple sounds like its trying to pump air and fluid...its does not develop pressure.
I wonder if when I replaced my swing arm bushings I distorted a compression fitting on the brake line or if I just need a new master cylinder.
Gio does not have one listed as a replacement part....anyone know a source?.........thx....waynec

Have you tried raising the rear end while bleeding them?, i know on our microsprints it was tough to get all the air out, it's probably worse on our beast because the master is higher than the caliper and air always rises to the top. Fill your master with fluid, raise the rearend, bleed the brakes and then top off the master with brake fluid.

Also is there any fluid leaking from the piston?, maybe one of the o-rings on the pistons is bad too.

No sign of any leaks. The resevoir had not lost its level. l was bleeding with the rear end way high....although quite by accident. On my machine the bleed valve is blocked by the the bottom plate so I had to remove the caliper to access it. I had the butt strung from a rafter to ease the removal. I also removed the master to investigate possible o ring replacement.....but it did not look terribly serviceable (quick and dirty, I mean) so I held off ..........waynec

The good news is that a similar caliper was used on several Honda products. Make sure to include dirt bikes, quads and trikes in your search.

Thx w&g I expanded my search parameter on the Gio site and they do sell the mst cylinder. It'll be $90 with shipping and tax.......but that will give me a spare caliper complete.....have to think on that......waynec

BLEEDING BRAKES..
 

You have to shorted the stroke and bleed it slowly.. put a wedge in the brake calipher to hold the pistons in as far as you can so they really do not move much at all... short strokes and hope it works for you... they are very hard to bleed.. on the atvs I have noticed that if there is air in the system from the factory.. little strokes will bleed the air out.. you will see small bubbles in the reservoir as you move the plunger... time and patience ... or money and no time.. take your choice..

thanks for the advice. I will try that. I have seen a few cylinders on ebay that appear the same. migh get in under $50. delivered....but..I have decided I will not spend $90 from Gio. If your tip does not work I will pull the o rings and see what I can find.........thx...waynec

I got around to pulling my master cylinder and have a pic of whats there. Its not much. I was hoping there might be a generic o ring with a bit of damage but everyting seems in order. The black seals are 'bell or umbrella" style seals. I have only had one other mst cylinder apart and it had similar type plungers. All I could think to do was run a little silicone under the seals to provide a little more pressure to the cylinder body. I hope there is no conflict with silicone and brake fluid. As I wrote previously this thing squirted a little like it was trying hard to develop pressure so i'm hopeful its just a minor problem.....waynec

http://s628.photobucket.com/albums/u...ast%20caliper/

Any roughness in the bore that would create a pressure loss?

Perhaps my final update on my brake struggle. I got a master cylinder off Ebay for a very good price. I think its from a Honda. Spent another couple of hours trying to bleed the brakes with no sucess. Maybe I just suck at this...but I have kept my sons Fourtrax going including brake work. I'm done. Tired of messing with stuff. The Beast is for sale.
http://ottawa.kijiji.ca/c-cars-vehic...AdIdZ226879202
waynec

Bummer. I hate when machines win.

DO NOT PAY GIO PRICES

i had this same problem for a good year and a half, had no rear brakes.
when i would press the pedal and crack the bleeder valve open it would squirt the fluid out like there was pressure.. but the master was failing under pressure..

this is the person i ordered my brakes from on ebay.. 40 bucks for a whole new rear brake system.. this is exactly what i ordered and use..now i have rear brakes and no brake issues

http://cgi.ebay.com/ebaymotors/Rear-...Q5fAccessories

That's crappy. Sorry to hear you're coming to this step.

Can't think of why this would be giving you all the trouble, especially with new parts.

my bad didnt read the comment saying it was for sale, read down to where it was said 90 bucks from gio.. bleeding should be the same as on the fourtrax.. if you have replaced everything it should all be working.. did you get rid of the craptastic brake fluid it comes with ?

Thx for the tip. yes i used new brake fluid. The cylinder for the Fourtax is on the handlebars. Bit of a different style and more meat inside the chamber but the concept is the same. At least with the Honda branded cylinder I now have I can probably order up a mst cylinder kit. If I calm down a little i may do this and keep the machine.

Hey Turbo....no it was a used cylinder off Ebay...not new..and I only paid 12 bucks incl delivery..so it may not have been working when it was last in service.

I have been fighting with the engine in a stern drive ski boat for 3 years now....the story I could tell about that adventure and I finally have it beat. I am still just a little tired of massaging all this stuff i have to keep it running. More time fiddling than having fun with some of it.....waynec

Turns out...I'm not crazy nor incompetant....so I got that going for me.
My rear brake is finally working. After 3 trips to 2 differnet Honda dealers and 2 orders for a mst cylinder kit I got the right one. Even with the greater pump pressure after the installation of the new seals I still had to remove the caliper and elevate it above the master to allow the air to rise and the fluid to settle.
For those that dont read back...this is not a Beast cylinder...this is a Honda branded master I got from Ebay. Of the 2 kits I had in my hands....neither is suitable for the beast master. The bore on the original cylinder is not 1/2 inch or 3/4 inch....its a size in the middle somewhere.
Murphys law decided the seller on Ebay did not identify the proper bike model this cylinder supposedly came from....hence my getting the wrong kit .. etc etc..etc

waynec

Good news on the brake! Are you going to keep your Beast?

The Beast stays for now. My sons Fourtrax did sell and it was used for light bush work pulling a small trailer. I am working up a trailer hitch for the beast today so I can get some firewood in.
A used Gio is a tough sell. All I got were inquiries from idiots and 12 year olds...many offering to trade their crap that would not sell, for mine.
I still need to track down my voltage drain or put a switch in to keep the battery alive for more than 2 days.
Is there something about the cdi that would keep a load on the battery? Its basically a capacitor, isn't it? If its constantly trying to maintain its charge could it be a very mild short to groung causing it to do that? Need an expert here.
thx
waynec

Just unplug your CDI and see if the battery drain is still there.

When you have a moment, please show us a photo of the hitch you developed.

battery drainage
 

try turning the kill switch on.. or check the ground wires.. if you do not have a good ground it could drain the battery.. also .. check the motor cooling fan.. I have the fan sensor send power to the fan while everything was off.. it did not turn but there was a small amount of power sent to it .. so it drained the battery.... some atvs have REMOTE controls.. they require power as they are armed and ready to use.. remove the fuse or turn the kill switch on.. DOES the battery hold a charge if you dis-connect for those 2 days????

I have the battery disconnected now and will be able to test for its charge in a day or 2. Thanks for the tips.

Here is a pic of my 'hitch'...respecting the KISS principle in all its glory. I cruised Princess Auto looking for a 4 sided bracket with an 1 3/4" opening to surround the lower shock mount. This is intended for some brand of shelving unit they sell. Drilled a couple of holes and slid in a longer bolt. Done deal and works ok. I snapped a pic of the trailer and the load of hardwood I pulled from the bush. The Beast had to work hard to pull this load........but look at this load!!......waynec

http://i628.photobucket.com/albums/u...r/beast016.jpg


http://i628.photobucket.com/albums/u...r/beast015.jpg

hitch looks good.. just remember the beat weighs in around i think 375 or was it 395 lbs. i will check my plate on the frame that has it.. but the point is to watch the weight of the the trailer. dont want it popping wheelies while hauling stuff and you dont want it to where it can lift the rear wheels off the ground..

if i ever buy land and decide i need a atv for work.. 4wd 700cc with a winch in front and one in the rear... the beast is actually pretty decent at work stuff. i just used it it to pull up a dead tree with the root system spread out a little over 3ft. pulled it up no problem, altho i could feel the rear suspension hunch down when the rope tightend

Excellent hitch! I think that's an E-track bracket, but I'm not sure. I might try the same thing; I hadn't thought of picking up the shock mount.

What is that dangling on the ground underneath it? Looks like a clear fuel line or something..

battery vent hose im guessing.. it runs up the rear shock towards the battery area. there is only 2 hoses hanging under our quads, carb bowl draining hose, and the battery vent hose.

Mizke got it.........i ran the vent clear of anything that could be corroded.....waynec

Funny I was so focused on the hitch ball assembly and just saw the hose there, I didn't even try to trace it up! Just looked like it was coming out beneath it. Duh. :?

hitch part
 

do you have a # for the piece that you bought from PA.?? Or what do they call that piece?? I would like to get one as well to do that.. was it in the surplus area?? nice job.. MIZKE gets the prize for finding the hose;s purpose..

its a shelving bracket.......thats all i remember. I will be back there tomorrow ..so I will see if i can get the brand name. It was not a surplus item......waynec

Yes....w&g had it nailed, no surprise, it is an "e" track bracket and it retails for $5.......w