I got air in my brake system because I let the master cylinder go dry. Wouldn't it make sense to bleed the front brakes first since they are the closest to the ABS module rather than pushing that air all the way to the rear brake bleeders? Just wondering if that makes sense.thanks

 

if i remember right the reason you do the back first is because they apply before front brakes and is why they are bleed first . my self just start at witch ever wheel im closest too as the vac bleeder i use dose not care. ..probably not right way to do thoo.

 

Just FYI, I use DOT4 brake fluid vs. DOT3, since it has a higher boiling point and is a pretty economical fluid choice. Before starting, make sure that you bench bleed the master cylinder before installing it on the truck (if you're working with a new master cylinder) and connecting the metal brake lines to it. When I bleed my brakes, I open the bleeder screw on the wheel that's farthest away from the master cylinder (passenger side rear) and let it gravity bleed, if I have time, as it can be slow. If I'm in a hurry, I'll use a MityVac vacuum pump to pull the brake fluid through the line to bleed that line (or have a friend pump the brake pedal without using a vacuum pump, if available), then go to the next wheel (driver's side rear) to do the same procedure. Repeat the process with the next two wheels (passenger side front, then driver's side front). All the while during the process, checking the master cylinder to insure it stays full of brake fluid. Once done, check the firmness of the brake pedal. If good, take it for a test drive. If bad, repeat the entire wheel bleeding process.

 

If you let master go dry there’s a good chance you’ll need to bench bleed the master, then bleed the 4 wheels

and I work on vehicles for a living…

correct order to bleed is furthest from master first….so in this order, Right Rear, Left Rear, Right front, left front.

 

That is how I do it, I already did it twice and still a spongy pedal. I was told I have to bleed the ABS module, and if there's air in it I thought it would make sense to get it out of the front bleeders since they are the closest to the module. I would be using the mityvac, not pumping the pedal, sothe rear brakes circuit would not come into play. This is just my idea, I really don't know the internal workings of the ABS module maybe somebody can enlighten me on this.

 

Go to a gravel road and stomp on the brakes, the ABS system has to engage. Do that after times then rebled them

 

If you've already bench bled the master you can try placing a vacuum on each wheel and then pump the pedal as you otherwise would for bleeding. This can often bleed the ABS module

 

In my experience, sometimes the MityVac bleeding method still doesn't get all of the air out of the system. If that process doesn't work and leaves you with a spongy brake pedal, get a second person to help you bleed the brakes with pumping the brake pedal (with the engine off) to build pressure up then bleed the brakes at the passenger side rear (farthest away from the master cylinder) and repeat the process with each of the other wheels (driver's side rear, passenger side front, then driver's side front), all while ensuring the brake master cylinder stays full of brake fluid.

 

This is very interesting. So I put my mityvac on the right rear bleeder, crack it open, draw a vacuum, then pump the brake pedal forcing air and fluid hopefully out the bleeder. Also being careful not to let the master cylinder go dry, and just keep repeating this until the pedal is firm. And if I put the bleeder hose into a container of clean brake fluid so that I don't draw air back in to the line when I ease up on the pedal for the second pump, it sounds like it might work.

 

So I just did my complete brake system on my 96. As it was mentioned, if the master went dry, take it off and bench bleed it. Then reattach and start the bleeding from the furthest away. I did allow for gravity bleed then had my son assist with the rest of the bleeding system. Brakes feel like new and work great.