I had her just pump the pedal until I got fluid, but since I never got fluid she I didn't feel there was a need to hold the pedal down. Are you saying just pumping the pedal won't get the fluid to the bleeders? I've bled brakes before but never had an issue with no fluids squirting out.

 

For 2-person bleeding, the process is:

Person A at the caliper
Person B operating the brake pedal

A opens the bleeder screw
A tells B to step AND hold down the brake pedal
B tells A "down" or whatever
A closes bleeder screw
A tells B to release brake pedal

lather, rinse, repeat.

somewhere in there, you periodically check/fill master cylinder.

But if you got NO fluid out of any of the bleeders at any time during this process, even just opening the bleeders and pumping a bunch of times, something else is wrong or the system somehow got pumped full of air.

Given your test of the MC by releasing the brake lines and brake fluid comes out of the MC there when you press the pedal, it sounds like the MC is working well enough.

Go downstream to the ABS controller and see what's happening there [basically do the same there as you did at the MC].

 

I had her pump the pedal several times but never got any fluids to squirt out so I didn't feel there was any reason to just hold the pedal down. Are you saying fluid wont make it to the bleeders unless you hold the pedal down? I've always said pump five times and hold, and repeat until no air was coming out, and yes making sure the fluid in the MC doesn't empty. Now going to the ABS controller and do the same thing? I don't even know where the ABS is or what it looks like...

 

As you press the brake pedal, the MC pumps brake fluid into the brake lines.
When you hold the brake pedal, it keeps the system static, so no fluid goes in or out of the MC into the brake lines
When you release the brake pedal, it releases pressure [and actually vacuums] brake fluid from the brake lines.

When bleeding brakes, you want to make sure the bleeder screws are closed when you release the brake pedal. If it is open, then air will be sucked in as the MC returns to it's 'released' position. When the bleeder screw is closed when you release the brake pedal, the MC will draw some fluid from the lines and/or allow more fluid from the reservoir to enter the MC.

 

Ill give another try tomorrow and post back with results....thanks to all for helping out!

 

What I would do is get some caps and block off the MC..see if you have a good pedal..that would eliminate the MC and point to the antilock brake assembly...
Also check all four calipers make sure all looks well with pads etc.

 

I had a similar problem while bleeding the brakes on my truck and eventually figured out that the idiot woman in the cab was pressing the gas pedal instead of the brake pedal because she got "confused". Any chance of that?

 

Would you happen to know what thread size they might be?

 

Ok went back tried bleeding brakes again as mentioned and still no fluids. Next Ill disconnect the two lines at the MC and screw in a couple of brass plugs at the two holes and check if I have resistant's on the brake pedal. Anyone know what size thread for those two lines at the MC?

 

if you had the bleeders open as she was applying and removing pressure from the brake pedal(up and down) than you definitely have air in the brake system.
we always pumped until we felt pressure and then held the pedal and shouted pressure so the guy at the calipers knew to open the bleeder
then he would close the bleeder and shout, ok pump it again. then repeat at each corner.


you should try gravity bleeding them,
get 4- 12 oz clear plastic water bottles and about 6-8" 1/4 vacuum hose for each bottle,
put holes in the water bottle lids for the hose to go through and put zip ties on the hose inside of the cap so the hose wont pull through,
make some wire hangers for the bottle to hang on the caliper.


attach each hose to the bleeders on all 4 calipers and open all 4 bleeders
fill the brake fluid reservoir to the top and leave the lid off before opening the bleeders. have extra fluid ready to add. you can do this alone but it's better with 2 people. one person watching the fluid/adding fluid making sure it doesn't run dry and another person checking all 4 corners for air and closing them off from farthest to closest.
after you gravity bleed you can pressure bleed to be sure.


gravity bleeding is also a great way to flush out old fluid

 

careful of what thread pitch your plugs are. I forget if they're 1/4" np or 3/8's

 

I don't know the size, but they are a tapered thread. You don't really need to plug them though. If you remove each fitting, on at a time, a simple press on the brake pedal will let you know if the master cylinder piston is pushing any fluid. It will jet out of the hole, so you'll want a rag to catch the fluid and keep it from spraying everything under the hood. Brake fluid will eat paint.

If you are set on plugging the outlets on the master cylinder, simply purchase a short steel brake line at Auto Zone or similar, cut the line so it's about an inch or two long then crimp it closed. Now you have a plug.

 

Master Cylinder replaced......problem solved. Thanks to all that helped out.

 

excellent news.

I'm not sure if this applies to your truck, but if you have an ABS controller, you MAY need to get the dealer or use a special ODB tool to properly bleed it, and then you can bleed the lines to each wheel.

 

I first bench bleed the MC and then installed bleeding just the MC lines after installing, then I was able to bleed all lines with the fluid squirting out properly... stops on a dime but I will keep an eye out. thanks again!