Forums š„ PiT STOP š§ Hyosung Technical Help Front brake not bleeding – GV125 2005 Carby [SOLVED]
- This topic has 5 replies, 2 voices, and was last updated 1 month ago by
ā ļø M77.
-
AuthorPosts
-
-
Mar 10, 2026 at 6:24 PM #22084Bike Model = : Aquila Gv125
Really having problems to bleed front brake after disconnecting hose to caliper due to seized pistons
-
Mar 10, 2026 at 9:08 PM #22086
You did not say if it is carb model or EFi,Ā so my reply below will assume it isĀ EFi model.
As it is CBS brakes, the rear cylinder being pumped also should help? Have you tried pumping the rear?Ā – This is to make sure no air from the front has gone to the back or air at the back has gone to the frontĀ (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.Ā Ā Keep doing it with the pads inside , so that all pistons push the pads togetherĀ (don’t attach to brake disc)
Then disconnect itĀ (dont push pistons) ,Ā connect the front and rear brakes together againĀ (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 caliperĀ (front) , you should see air bubbles in the cylinders making a sound or moving.Ā Ā Pump the front again until pistons full extend to touch the pads maximum,Ā push the pistons back to flat,Ā repeat this until you know the front is now good.
The rear should be getting better, push the rear pistons flat , and repeat,Ā then test your brakes.Ā Ā It will be time consuming,Ā 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.Ā Ā (if your pistons seized,Ā your master cylinders where probably tired from fighting to push the pistons out?)
If it is a carb modelĀ = Don’t worry about rearĀ (it uses drum brake) , just focus on the instructions i said about the front only.
-
Mar 11, 2026 at 7:46 AM #22088
`thsnks for your information , sorry not efi model . it’s a 2005 year.
-
Mar 12, 2026 at 4:15 PM #22095
`thsnks for your information , sorry not efi model . itās a 2005 year.
No problem, a 1 man bleed kit should do it following what i said about the front potion where i sometimes do it the old fashioned strange way!
-
Mar 12, 2026 at 5:22 PM #22097
Managed to get the pistons out and used the reverse bleeding syringe to pump the brake fluid from brake bleeding nipple back up to the reservoir. Now all good.
-
Mar 13, 2026 at 11:39 AM #22104
Nice work!!
-
-
AuthorPosts
- You must be logged in to reply to this topic.