Brake Pedal goes to floor after shoe and cylinder change

Changed the shoes, springs, and turned the rotors on the rear brakes. I also went ahead and replaced the wheel cylinders too since the truck is old and I didn't know when they were last done. Upon test driving the truck wouldn't stop unless you put your foot to the floor. After bleeding all the wheels again, same problem.

I found out there is a "fifth" bleeder located on the BPV Brake Proportioning Valve Assembly. On my truck this was located directly over the driver rear tire. (All the rear brake lines run to it) After bleeding this out after bleeding all the wheels, since it is higher, the is improvement but it still isn't what it used to be, lots of spongy pedal travel.

I guess the next step is the master cylinder. I have bled all four wheels and the BPV until only fluid is coming out. If anyone knows what do do please let me know, I do not want to buy a new master cylinder and especially do not want to pay someone to install it.

I'm sure this is a repeat of previous threads, but hopefully someone looking to do their brakes will see this and realize there is a fifth bleeder valve to worry about. I will post a picture of it soon.

 

Can't tell from your description if you changed (or even just messed with) the calipers on the front. If you did, were you sure to re-install them on the correct sides (so the bleeder is on the top of the caliper). Some folks get them installed with the bleeder on the bottom, and then you can't get the air out. If you have a photo of the calipers as installed, that should be easy to determine.

Also - when bleeding, did you follow the "correct order"? Passenger Rear, Driver Rear, BPV, Passenger Front, Driver Front

 

I did do the correct order, and all I did to the fronts was bleed them when everything else went sour. I did adjust the rear brakes properly using the star wheel as well.

I just drove it after bleeding the master and the wheels again. It seemed to be almost back to normal, then I heard a pop when braking hard and it went back to squishy. I do not see any evidence of leaks even after that.

 

I’d be willing to bet you’ve got your adjusters installed incorrectly. Especially based on the “pop”. It probably slipped down further into the groove. I don’t think you’re dealing with a hydraulic issue.

 

The drum adjusters? They're set to where they scrape a bit while driving. (I did that to make sure they weren't causing the pedal problem) I should've mentioned the pop sound seemed to come from the front passenger tire but I did not see any leaks.

 

What do you mean “scrape a bit”?

 

The shoes are adjusted to where you cannot easily turn the drum.

 

Did you top off the brake fluid after bleeding?

 

Ok gotcha. But have you looked to verify the adjusters themselves are properly seated in their grooves in the shoes? Have you pulled the wheels and drums off since hearing the pop?

 

I did.

I have not since hearing the pop. I will try to later today though I imagine it would make a lot more noise than a single pop

 

Are you losing any brake fluid?

 

Nope. No leaks and only needing to fill the master cylinder after bleeding.

 

Bleed em again.

 

Probably will have no choice if everything else still checks out. I will say that the last time I bled there was almost no air whatsoever. Barely enough to mention and only at the very beginning then it was pure fluid.

 

first thing... how many clicks do you get when pulling the e brake lever out... this gives an indication of the adjustment of the rear shoes. I think 22 clicks is normal until it gets harder to pull.
take the e brake off. with the motor off, press on the brake pedal a few times to bleed the any vacuum off the booster. Wait a minute then slowly press the pedal, if it is firm immediately this is a good sign that the hydraulic aspect is ok. If it goes to the floor there is either air or the rear shoes are out of adjustment.
pull the e brake cable as far as you can then step on the brake. if it gets firm the rear shoes need adjusting, if it goes to the floor press the brake a few times quickly and hold it. let off just a little and see if the pedal slowly drops to the floor or holds. If it drops, the master cylinder is no good.
let the brake pedal up, push down on it lightly and start the motor, the brake pedal should drop a small amount, this tells you the booster is working. hold that pedal position and shut the motor off. if the pedal rises the booster doesn't hold vacuum long enough. When bleeding do the master first. if the master is installed wrap a rag around the lines one at a time that exit the master crack the line and have someone step on the pedal and hold it while you tighten the line, repeat on the other line then bleed the farther from the master cylinder first, then the next and so on.

 

About 16 clicks until it gets harder. I can get to about 25 clicks. The first thing you told me to try, it is pretty firm with the e brake off after pumping then waiting a minute. I tried that twice. Pedal is immediately firm but not rock hard.

Pulled the e brake and the brake pedal is firm. I also pressed down more and the pedal did not sink without me pushing it.

Did the hold pedal lightly and started the car idea. It held, did not let up until I did. The pedal did not rise until I let go.

Basically, everything feels great until I start the car. Yesterday the pedal went to the floor. Today after doing these things, it feels better, but still not as it was before. There's just more travel until the brakes engage. I'd estimate about an inch more of travel. I was advised to just drive the car and maybe the computers will adjust. It will stop as I said just more pedal travel than I can put up with. But these steps seem to have improved something. Should I adjust the rear shoes outward more?
And thanks for your help @Glamisman

 

I would think that adjusting the rear brakes until the wheels are hard to turn, as you have written, is too much. I have been adjusting mine until the wheels just begin to scrape, and have been doing it that way since 1960 without any problems.

Just saying. In any event, I don't think the rear adjustment has anything to do with your problem. Have a look at Timmah's brake adjustment video just to verify that you did everything right. https://www.youtube.com/watch?v=IJkVEBYSecs

 

Looks like I did everything right. I did not grease the inside of the self adjusters but they turn easily so I don't think that's what's causing my problem. My drums are obviously done a bit tighter, but I did so to ensure they were not the problem. Plus, shoes adjusted to be too tight wouldn't cause the brake pedal to go to the floor.

 

Okay. If you reassembled everything according to the video, then I think that the only thing left that fits the description in your original post is the master cylinder. Maybe when you replaced the wheel cylinders enough fluid drained out of the MC to cause something in it to not reset correctly. Dunno, but if it were I, I would rebuild the MC.

 

Yup, I was there. Replaced shoes and drums, adjust rear e-brake and then rebleed the rear cylinders and then the bpv. Feels solid