Brake problem

2011 extra cab 4x4 v6 auto 210,000
six months back seems like I lost some brake pedal, but still stopped ok, except I noticed on gravel or dirt, it would slide front wheels.
Replaced front pads, they were paper thin but not into the metal.
Rear shoes looked almost perfect, at 196,000 mi.
brake pedal seems to be worse now, fluid has never been low.
Left rear wheel bearing got noisy, replaced it, hook up brake line and bleed with a one man bleeder. has about two ounce bottle, then bleed right side, no bubbles. Both sides only put about 1/4 bottle of fluid in it after each bleed. And I pumped it multiple times with very little if any pedal. Bleed right front brake, then left front and both of them after three pumps would almost fill the bottle. And there was about a quarter of what I would expect of brake pedal. Brake fluid never got low, checking it after each bleed. I now have very low pedal and front brakes seem to be the only ones working. I am thinking master cylinder, but thought I would check in here first.
Any help is appreciated
thanks
Oscar

 

The rear shoes probably need to be adjusted.

 

Agreed. The shoes don't move all that much and the majority of your stopping power is up front anyway, so if the shoes aren't properly adjusted, it can seem like you have little to no brakes.

Also, have you followed the brake lines just to make sure there were no wet spots? I know you said the fluid was never low, but still.

 

yes, the rear brakes did need a lot of adjustment, but did not change anything

 

I have not followed the brake lines, but I will check, I mentally eliminated that since I was never low on fluid, but who knows?

 

Did you adjust them so the brakes lock up then back off a couple clicks?

You could have a bad master cylinder but I suspect something with the rear drums.

 

No I didn’t adjust them up that tight
Guess I will give that a try this afternoon
Thanks

 

Yeah, drum brakes can be kind of weird. What you think is adjusted enough isn't enough resistance.

 

Update on the brake issue
Adjusted rear brakes to the point of significant amount of drag, couldn’t tell if it changed any
Bleed all brakes again and got more air out of left rear, well that seems to have done the job, brakes working normally now
Thanks for all the suggestions!

 

I hope you didn’t leave it with a significant amount of drag.

 

You should have them right enough that when you spin the hub, it shouldn't spin freely more than 180*.

 

Take a look at that left rear brake line - that it had air on the second check is curious since you certainly sound like you know how to bleed brakes- could indicate a leak in that branch.

 

You don't think they will self clearance pretty quickly?