Can't get brakes to bleed (78 Chevy K10)

Check if the calipers are switched side to side.

What method of bleeding are you performing? Are you getting a steady stream of solid fluid at all 4 corners or are there still bubble present? Did you let the master cylinder go dry and not bleed it leveled out so trapped air can be expelled? Are the rear brake shoes adjusted out properly? Internal leak in the master cylinder?

Halfway thru the second quart of fluid and no pedal is when you need to back track and find the problem.

Three things come to mind.

First as mentioned, are the calipers on the correct sides so the bleeders are at the top?

Second is a dry MC. If the MC went dry, it likely needs a bench bleed to get the air out of it. This can be almost impossible on some to do while in the vehicle. The MC must be level and on some, you must push the plunger in farther than the brake pedal can push it so the MC needs to be on the bench.

Third is a the lockout pin on the combination/proportioning valve that is used to get the air out of it.

On some combo valves, there is a rubber boot on one end covering a pin. This pin must be held from moving to get the air out. Some push out, some pull in. I use a helper with 'channel lock' pliers or vise grips to hold it or a hose clamp holding a penny over the pin.

Mike

When I had this problem on my race car, I found a pinhole leak on one of the hard lines that was preventing me from getting all the air out.

It sounds like you're doing the right thing, but I suggest taking a "step back" and starting over - assume the whole system has to be bled, check for leaks everywhere, make sure you're getting a good solid stream of fluid from each wheel before moving on.

Ray

Thanks for all the help.

I had the calipers on the wrong sides. I didn't know you could install them on the wrong side. Once I switched them I was able to bleed them in about 30 seconds.

Thanks again.

Just FYI, there is also a right and left on the rear brake adjusters. If you get them mixed, the emergency brake will fast go slack and the pedal height will fast drop down.

Mike

In addition to what's been said, it is sometimes useful to fill the master cylinder, leave the top off or loose, and open a bleeder and let it sit for awhile. Eventually, (usually), fluid will come through, and some of the air will make its way through.

Dave

stuff happens. :)

FWIW, I learned to always do one side of the car at a time for brakes. It prevents mixing parts up, and it gives you a handy reference for when you're wondering how this spring or that clip goes on.

Ray

Good idea, but if he was putting on rebuild calipers the same mistake could be made.

Just remember, bleeder will be on TOP (air rises!)...

--Ken

ah... but if you did one side at a time and had two rebuilt calipers, you'd notice that one way would be "right" and the other would be "upside down"

Ray