This past weekend I was working on two separate friends’ motorcycles trying to prepare them for a track day. In the past month or so all three of us had undertaken the task of rebuilding our brake calipers, along with installing new stainless steel braided brake lines. Once the calipers were rebuilt and the new lines were installed on the bikes, we all realized the fun was just beginning. We were now to the point of no return, and we were faced with the task of filling the new system with brake fluid. But first, we would have to bleed the entire system of all the air that was trapped inside.
First, we decided to try the “traditional” method of pump the lever up where you have one person hold the lever while the other works the bleeder valve at the caliper. While this did start to work after about an hour it was not getting us to that peak performance we were looking for in the amount of time we wanted to get there.
Next, we decided to try a small vacuum pump that you pump by hand. This method had worked well for us in the past on other occasions but, just seemed to be taking a lot longer because of the volume of air in the “new” system. This is when a light bulb flipped to the “on” position in my head and I thought, “ Why not use an E-Vac Generator in place of this little hand pump and get this job done a lot faster and maybe easier?“
So, that’s when the engineering began, we created a compressed air driven brake bleeding system. Seeing that the hand pump was generating at most 30” of Hg when sealed off and approximately 15” of Hg when bleeding the brakes, we decided to try the model #800003. This E-Vac will provide up to 21” of Hg, so we thought it would be a good starting point. With the E-Vac in place, we all three took our positions and began bleeding our brakes utilizing the new bleeding system we created.
A picture of our E-Vac brake bleeding unit is below. I realize it is not an ideal condition but it proved our theory.
After implementing the new bleeding system we realized you can bleed an entire dry brake system with one person faster than if you were using the traditional or hand pump system. The nice thing about this system is that it is simple to use, and you can bleed the brakes all by yourself.
While we used a small E-Vac from the EXAIR catalog, it would be rather easy to size and implement a larger E-Vac to be used on virtually any hydraulic system that needs to be bled.