Like many others, I have run into the problem of bleeding the Hayes Brake system. Once you remove the brake line from the caliper that's when the problems start.
The key is to compress the pistons before you start the process. If you leave the pistons in a extended position air will get trapped behind them.
You can use what ever filling technique you want at this point and follow basic bleeding technique's, but keep in mind that it's much easier to push air up rather than down. For this reason I like to use a syringe and fill from the bottom up. This method fills the caliper first and pushes the air up through the mc. This is also a good method to change dirty fluid. As you push new fluid into the caliper you can soak up or suck out the dirty fluid with a vacuum pump.
Another tip is to angle the mc so that the piston is above level to the ground (or higher than the brake line). If you fill from the top down, it is necessary to bleed out air from the piston in the mc by flicking the lever not stroking it.
I struggled with bleeding my system earlier this week and I can tell you that the one thing that made was difference was compressing the pistons first. Once I did that the system primed and I was done in about 3 min.
Disclaimer: I cannot take credit for knowing that there is air trapped behind the pistons. I called Hayes and talked to an engineer. This was his suggestion.
Good luck to all!
The key is to compress the pistons before you start the process. If you leave the pistons in a extended position air will get trapped behind them.
You can use what ever filling technique you want at this point and follow basic bleeding technique's, but keep in mind that it's much easier to push air up rather than down. For this reason I like to use a syringe and fill from the bottom up. This method fills the caliper first and pushes the air up through the mc. This is also a good method to change dirty fluid. As you push new fluid into the caliper you can soak up or suck out the dirty fluid with a vacuum pump.
Another tip is to angle the mc so that the piston is above level to the ground (or higher than the brake line). If you fill from the top down, it is necessary to bleed out air from the piston in the mc by flicking the lever not stroking it.
I struggled with bleeding my system earlier this week and I can tell you that the one thing that made was difference was compressing the pistons first. Once I did that the system primed and I was done in about 3 min.
Disclaimer: I cannot take credit for knowing that there is air trapped behind the pistons. I called Hayes and talked to an engineer. This was his suggestion.
Good luck to all!

DMCTurbo
VIP Member
- Joined
- Nov 12, 2005
- Messages
- 2,823
- Reaction score
- 2,572
- Points
- 1,623
- Location
- Val Caron, Ontario
- Country
- Canada
- Snowmobile
- 2017 Sidewinder XTX LE 137
Thanks for the tips! I'll be tackling this soon.Like many others, I have run into the problem of bleeding the Hayes Brake system. Once you remove the brake line from the caliper that's when the problems start.
The key is to compress the pistons before you start the process. If you leave the pistons in a extended position air will get trapped behind them.
You can use what ever filling technique you want at this point and follow basic bleeding technique's, but keep in mind that it's much easier to push air up rather than down. For this reason I like to use a syringe and fill from the bottom up. This method fills the caliper first and pushes the air up through the mc. This is also a good method to change dirty fluid. As you push new fluid into the caliper you can soak up or suck out the dirty fluid with a vacuum pump.
Another tip is to angle the mc so that the piston is above level to the ground (or higher than the brake line). If you fill from the top down, it is necessary to bleed out air from the piston in the mc by flicking the lever not stroking it.
I struggled with bleeding my system earlier this week and I can tell you that the one thing that made was difference was compressing the pistons first. Once I did that the system primed and I was done in about 3 min.
Disclaimer: I cannot take credit for knowing that there is air trapped behind the pistons. I called Hayes and talked to an engineer. This was his suggestion.
Good luck to all!