sheffieldtrials Posted March 28, 2009 Report Share Posted March 28, 2009 Hi guys, I recently purchased a 99 321 GasGas, and the front brake was pretty bad but good enough to do a few practise days on. I eventually got round to bleeding the brake, but I have never been able to get them any better, still very spongy. I used a syringe and pushed the fluid in from the caliper numerous times, even had the caliper off to twist it incase there was any trapped air. When i watch the calliper it just literally bends, so im wondering if my problems are due to the HEBO calliper on my bike being just poor but my brakes have no air. I can pull the brake on then keep pulling it with one finger and watch the calliper bend, even with a G-clamp round it!! I was thinking is it worth getting a better calliper? maybe a Brembo? Have you guys had any similar problems? Other things i have done is replaced the master piston. Disconnected the caliper and blocked the pipe, resulting in a nice firm lever so the master cylinder is good. Cleaned up the pads and disc. My only real comparsion is my 1990 gas gas and TR34 beta which both use a Brembo system with single piston caliper but they work much better. Any help or opinions would be much appreciated. Cheers, Shaun Quote Link to comment Share on other sites More sharing options...
jse Posted March 28, 2009 Report Share Posted March 28, 2009 Hi guys, I recently purchased a 99 321 GasGas, and the front brake was pretty bad but good enough to do a few practise days on. I eventually got round to bleeding the brake, but I have never been able to get them any better, still very spongy. I used a syringe and pushed the fluid in from the caliper numerous times, even had the caliper off to twist it incase there was any trapped air. When i watch the calliper it just literally bends, so im wondering if my problems are due to the HEBO calliper on my bike being just poor but my brakes have no air. I can pull the brake on then keep pulling it with one finger and watch the calliper bend, even with a G-clamp round it!! I was thinking is it worth getting a better calliper? maybe a Brembo? Have you guys had any similar problems? Other things i have done is replaced the master piston. Disconnected the caliper and blocked the pipe, resulting in a nice firm lever so the master cylinder is good. Cleaned up the pads and disc. My only real comparsion is my 1990 gas gas and TR34 beta which both use a Brembo system with single piston caliper but they work much better. Any help or opinions would be much appreciated. Cheers, Shaun What you might try first is to take the caliper apart and face the mating surfaces by sanding them on some 280 grit wet/dry sandpaper. Put the sandpaper on a level surface like a surface plate or piece of glass and move the caliper mating surface in a figure 8 pattern. You'll be able to see when the surface is level by the even pattern. Re-assemble and add a little fluid to the caliper before hooking up the hose to make bleeding easier. This should eliminate or at least reduce the flexing to the minimum. Jon Quote Link to comment Share on other sites More sharing options...
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