Hey yall,
I recently replaced the caliper in my hydraulic brake kit from BMIKarts: brake kit since I believe it broke. I bought a replacement caliper off of Amazon. Since I am replacing the caliper, I had to bleed the brakes.
To bleed the brakes, I first opened the bleeder screw, press the pedal, close screw, release, and repeat until no more air bubbles come out for maybe 10-15 minutes. After doing that and testing it, the brakes were weak. The pedal was fairly spongy, but the go kart did eventually stop, it just took a while. This was very different from before; the old brakes used to be very firm and stop right away. I figured that there was still some air left, so I kept bleeding for half an hour but no air bubbles came out.
I decided to gravity bleed the brakes by propping up the master cylinder (keeping it pressed with a zip-tie), and left the bleeder screw open overnight. The result were about the same: still spongy pedal feel and weak brakes.
I tried one more thing which was combine the 2 methods above. I opened the bleeder screw, held up the master cylinder, pressed the MC, close screw, release, and repeat. A lot of air bubbles did come out, but the situation did not really improve. The brakes were slightly stronger, and the pedal did feel less spongy, but nowhere near as before. However something strange also happened. I pumped the pedal fast and strong for like 5 seconds, and the pedal would go from weak/spongy to fairly strong/firm. I tested this while running and the brake felt stronger and did stop faster, but after that it could go back to being spongy, and for it to be firm again, I would have to pump it again.
I would like to mention that throughout all these, the caliper piston DOES move, and the pads do touch the brake rotor when the pedal is pressed. When I am stationary and I press the brakes, it is hard to move the kart. The brakes pads are also brand new.
I am not sure why this is happening but I have 2 reasons:
1. The brake rotor that I have: brake rotor, is too small and the caliper is not built for that size (would be strange since it should be a replacement caliper from the one I had before).
2. Somehow, there is still air trapped somewhere somehow after all the hours of bleeding.
If yall have any helpful tips, that would be greatly appreciated since I am very close to buying the brake kit again.
I attached some pictures of the caliper.
Let me know if I need to clarify anything.
Thank you
I recently replaced the caliper in my hydraulic brake kit from BMIKarts: brake kit since I believe it broke. I bought a replacement caliper off of Amazon. Since I am replacing the caliper, I had to bleed the brakes.
To bleed the brakes, I first opened the bleeder screw, press the pedal, close screw, release, and repeat until no more air bubbles come out for maybe 10-15 minutes. After doing that and testing it, the brakes were weak. The pedal was fairly spongy, but the go kart did eventually stop, it just took a while. This was very different from before; the old brakes used to be very firm and stop right away. I figured that there was still some air left, so I kept bleeding for half an hour but no air bubbles came out.
I decided to gravity bleed the brakes by propping up the master cylinder (keeping it pressed with a zip-tie), and left the bleeder screw open overnight. The result were about the same: still spongy pedal feel and weak brakes.
I tried one more thing which was combine the 2 methods above. I opened the bleeder screw, held up the master cylinder, pressed the MC, close screw, release, and repeat. A lot of air bubbles did come out, but the situation did not really improve. The brakes were slightly stronger, and the pedal did feel less spongy, but nowhere near as before. However something strange also happened. I pumped the pedal fast and strong for like 5 seconds, and the pedal would go from weak/spongy to fairly strong/firm. I tested this while running and the brake felt stronger and did stop faster, but after that it could go back to being spongy, and for it to be firm again, I would have to pump it again.
I would like to mention that throughout all these, the caliper piston DOES move, and the pads do touch the brake rotor when the pedal is pressed. When I am stationary and I press the brakes, it is hard to move the kart. The brakes pads are also brand new.
I am not sure why this is happening but I have 2 reasons:
1. The brake rotor that I have: brake rotor, is too small and the caliper is not built for that size (would be strange since it should be a replacement caliper from the one I had before).
2. Somehow, there is still air trapped somewhere somehow after all the hours of bleeding.
If yall have any helpful tips, that would be greatly appreciated since I am very close to buying the brake kit again.
I attached some pictures of the caliper.
Let me know if I need to clarify anything.
Thank you
....