Replacing Front Brake Hoses: Preparations to Bleed Brakes

Video Transcript

"In this segment we're going to cover bleeding the brakes. Basically I want to walk you though here and just take a minute or two and give you a brief over view and explain to you what we're going to do and how we're going to do it. As you've noted earlier, the start of this training video this is where you're going to need your second person at. To bleed the brakes what we're doing is removing any air in the system that may have gotten in while we removed that brake line. So, anytime you open the braking system, I don't mean the reservoir on the cap to add fluid, I mean remove a line or crack a line loose below the master cylinder you have to go through the brake bleeding procedure to get that air out of there so that you're vehicle will operate correctly. If there is air in the system hydraulic fluid or fluid will not compress. The brake fluid will not compress, by you stomping on the pedal it forces brake fluid under pressure down through the lines and that collapses the pistons causing brake pressure and the vehicle will slow down. If there's air in there that air will compress and thus absorbing some of the energy not transferring into the calipers and applying pressure here. So, we need to remove that air out of there, so we have no give in the system. It's completely hydraulic and that will alleviate any fade and ensure that all braking pressure applied is getting directly applied to our brake pads and thus slowing the vehicle. The procedure used to do that. You get your second person and walk through this with him or her, whoever you're using, and what you want him to do is pump the brake pedal slowly three times and hold his foot down. Where ever it may stop. At that time you'll open this bleeder valve and his pressure will go down then at that time and the fluid will come out of the valve and any air in the system. You'll see bubbles popping out mixed in with the fluid. Once the brake pedal goes down to the floor he must stop his foot movement at that time. Holding the brake pedal to the floor and you tighten the fitting back down. If he doesn't; if you don't follow that procedure when they release the brake pedal back pedal up it sucks air back in and then when you've closed the line you've pulled more air back into the system. So, the object is three pumps, that builds up pressure, open the valve that lets out the fluid and the air in the system, of brake fluid; brake pedal goes to the floor, he holds it there until you give him the command to release, you tighten the valve, he releases. So, essentially I'll say pump, the individual inside will give me three pumps and tell me "OK." I open the valve and release out the fluid in there. The second it comes down to the floor the fluid starts coming; stops coming out which indicates to me he's gotten to the floor. The person will tell you "floor." You'll see it stop. Lock the bleeder valve down and you can say release. Then give them the command pump. You'll want to do the procedure at least three times roughly as a minimum for good guidelines and then check the fluid if you need to go any further. But, what you are looking for and I'll show you in a procedure, is air bubbles coming out. That will conclude part one of bleeding the brakes, please watch our next segment. We'll cover part two of bleeding the brakes."