Reply To: Front brake not bleeding – GV125 2005 Carby [SOLVED]
You did not say if it is carb model or EFi, so my reply below will assume it is EFi model.
As it is CBS brakes, the rear cylinder being pumped also should help? Have you tried pumping the rear? – This is to make sure no air from the front has gone to the back or air at the back has gone to the front (vise versa)
A quick test = Disconnect rear cylinder or find a way to make sure the front caliper only has 1 hose attached to it going straight to the front cylinder , bleed & pump the brakes with a 1-man bleed kit found all over amazon / ebay. Keep doing it with the pads inside , so that all pistons push the pads together (don’t attach to brake disc)
Then disconnect it (dont push pistons) , connect the front and rear brakes together again (making sure the rear caliper has pistons pushed out to touch the pads without touching the disc.
Now Reservoir caps off from both cylinders for air to escape.
Push the pistons down flat inside the caliper (front) , you should see air bubbles in the cylinders making a sound or moving. Pump the front again until pistons full extend to touch the pads maximum, push the pistons back to flat, repeat this until you know the front is now good.
The rear should be getting better, push the rear pistons flat , and repeat, then test your brakes. It will be time consuming, but this is another “old school” method i use sometimes when i am doing multiple brakes at the same time or even my older generation GV that has two discs at the front!
Another way the bike loses pressure;
- Copper Washers on the banjo bolts need replacing.
- Pistons seals are hissing air or not sitting properly.
- Seals damaged for pistons.
- master cylinder is wanning. (if your pistons seized, your master cylinders where probably tired from fighting to push the pistons out?)
If it is a carb model = Don’t worry about rear (it uses drum brake) , just focus on the instructions i said about the front only.