Just changed my pads + rotors and drums + shoes today only to find my brake pedal soft and sinking to the floor : I didn't have this problem before but changed the pads and rotors as the previous owner installed smaller rotors and was wearing out the pads unevenly. The rear for preventative maintenance. I lubed the guide pins for the pads and changed the hardware. As for the rear, I changed out the drum springs hardware and self adjuster repair kit.

​​​​​​The wheel cylinders looked ok so I didn't change them. I also don't remember adjusting the adjuster on the bottom of both brakes, not sure if that would cause a soft brake pedal but i read they should automatically adjust anyways. I did bleed the brakes to the best of my ability lol it was getting dark out and I lack experience.
I didn't see any leaks anywhere and the brake fluid is at Max.

I'll look more into it tomorrow so some insight would be appreciated!

Edit: the brake is also soft when the truck is off but builds up a little pressure when I repeatedly press the brakes. It doesn't get as hard as it should though.

 

A. Drums absolutely must be adjusted when replacing the shoes. They do self adjust but only in extremely small increments over long periods of time. Also if the self adjusters are fully closed they will never adjust. Start by adjusting the drums. They should be adjusted until the shoes just start to drag on the drum.

B. You have air in the lines. You need to re-bleed all 4 wheels. Starting at the right rear, left rear, right front, left front. I don't know what procedure you used so I cant say what you did wrong but I suggest watching some videos on proper bleeding procedures.

C. The smaller rotor thing has me extremely confused and worried. Got any pics of the old pads and rotors vs the new?

Also I hope you don't take this the wrong way but you seem pretty inexperienced with brakes and I'm a stickler for safety, if you can, take pics of everything so we can check your work for any other issues. There's lots of things that even experienced mechanics can mess up like putting the shoes on backwards, adjusters on backwards, caliper pins greased with petroleum grease, etc etc.

 

A. Right. I'll have to look up on YouTube for a 'How To' I'm not sure. I have changed pads and rotors before but only on fwd cars. The whole rotor assembly with wheel bearings and oil seal plus the drum brakes was all new to me lol

B. Yeah that's the same procedure I did. Only, I probably only pumped the brakes once or twice all the way to the floor. I only bleed them after I noticed my brake pedal was soft. I was thinking maybe air got introduced into the system when I took off the pins on the wheel cylinder that pushes against the shoes to clean them with sand paper.
C.
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This is the rotor

As for the new ones, I believe this is the passenger side


And driver side

 

And the drums brakes

Passenger side
Passenger side
Driver side
Driver side
I found some (not a lot) brake fluid on the drum when I took it off this morning so it looks like the cylinder is leaking on the driver's side.

 

Here's one of many videos on how to blead the brakes by yourself, but I never could get this method to work, no matter how little I cracked the bleed nipple.

Air was inevitably sucked past the threads _ ALWAYS.
Not only that, if the pedal stroke doesn't fill the line into his pop bottle with fluid when the pedal is released, it will suck air in the line back into the system.
In the video it doesn't show this happening _ it doesn't make sense at all.


I always had to have someone close off the bleed nipple when I released the pedal.
Putting heavy wheel bearing grease on the nipple threads keeps air from getting sucked into the system.

 

Everything looks good as far as installation but that wheel cylinder definitely looks like its leaking. They arent expensive at all so I would just replace both and then do a full bleed.

One little criticism, put a tiny dab of RTV over the screw driver hole in the spindle cap so water cant find its way into the wheel bearings.

 

Good idea Jeff on putting grease on the threads IIll have to give that a try

Apex, I ordered the parts online last night I don't know why I didn't just change them when everything was off to make installation easier
Haha yeah that cap was a pain to get off for whatever reason and accidentally poked a hole while gently hammering a flat head to pry it out. Good thing I have some RTV laying around.
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Alright so I pressed the rubber end of the wheel cylinder and brake fluid comes out. This pretty much confirms a shot cylinder and the soft spongy brake I'm getting? I took it out for a test drive earlier and although it brakes fine, it's not as responsive as I'd like and I have to press the brake in further to the floor to come to a complete stop

 

Yup, definitely a dead wheel cylinder. They are usually only 15 bucks or so.

 

Alright I'll see if I can do it this weekend

 

Alright so I changed out the wheel cylinders and bled the brakes and my pedal isn't as soft but it's not as firm as I would want it to. And I hear a hiss every time I depress the brake, don't know if that's normal or not. Could I still have air in the system? I pumped the brake pedal and held it down with a pipe jammed against the seat and pedal and cracked the bleeder valve open. Did that 3 times for both sides

 

I'm still gonna say you need to bleed it more. Sometimes you need to open - pump - close - release a bunch of times. You need to physically watch for air bubbles coming out. I highly recommend finding a buddy to help out so you can work the bleeders. And remember you may still have air in the front brakes too. Bleed all 4 wheels!

 

You're right man! Bled the brakes and now the pedal is solid and firm. It stops better than I remember. Thanks for the help