Brake pedal slowly sinks to floor

Are you a manual or auto trans?
My 08 2.7 uses the same master and resivor for both brakes and clutch.
Unsure if it has anything to do with your issue but I do as much of my own wrenching as possible and the 2 using the same stuff may be a maybe.

 

We are waiting to hear the solution.........

 

^

 

Master Cylinder is leaking, this is a test they taught us back in school. If the pedal slowly keeps going down, the MC is going out. Get that thing replaced ASAP before you fly into a wall at 60 mph

 

Spit balling here but I had a similar situation on my old Toyota pickup when I blew a rear brake line.
It might be a proportioning valve problem. After I had the line replaced, my pedal was doing the same thing and it was not losing any fluid. I heard and tried....stomp the brake pedal several times, real fast. You don't have to be moving when you do this. Just stomp it several times really fast and maybe it will allow the valve to shift back to where it belongs. I know it sounds crazy but mine was fine after doing this a couple of times.

 

Totally thread jacking while we wait for a solution but I’ve seen you in all the brake threads, Bill.

I did some SS lines and bleed today. I never once got pure fluid out of the bleeder valves it was always bubbly. After about 16 oz of fluid I Decided my method was dead wrong and went to take it to a mechanic. So I slowly back out.. check the brakes. Best The truck has ever felt.

What’s going on here?

I was using a harbor freight vac bleeder btw.

 

Nah. Not really. I've just done enough of my own that I have a bit of experience to offer.

I can't really say. I've never used a vac bleeder of any kind. I know they are all the rage, but I've always been successful with 2 person pedal pumping. Or on a car I did a lot more fluid changes, using speed bleeders.

It's always good to include your year truck and such in your profile, or in your post, when asking for tips. It might matter in getting the best answers.

Did you bleed the whole system? And if yes, starting at the furthest point? Any chance the ABS got drained some? As in will the truck stop well with a good pedal, but the pedal fall at idle, under pressure, as if the master were bad?

 

Remember with the vacuum bleeder when you loosen the bleeder screw it can/will pull air bubbles from the threads around the outside of the bleeder screw. So you might actually have all the air out of the system hence the better then ever feel.

 

That has been my experience with vacuum bleeders. But, I've always got a good bleed with them.

 

It is a 2011 Toyota Tacoma
2 wheel drive
Automatic
And has a little over 76000 Miles on it
My son just texted today to say the brakes were slipping AGAIN
Aarrrggghhhhh

 

Ok. No fluid loss?

I'm going with air in the ABS system.

Likely to require someone with a Techstream device to successfully bleed.

 

Hi Clearwater
No fluid loss that we could see
We have replaced pretty much everything now
Had all the fluid flushed and replaced
It worked for a week and then we got the text today that it isn’t
Making arrangements to get it back from our son to start working on it again
We will check about the air in the ABS

 

ModestMods
That’s how I feel too lol

 

Okay so the problem continues
The brakes are grabbing so bad when you go forward
We went in reverse and at first it seemed to unlock it but now that isn’t working
It sounds horrible


Edit:
Possible fix: the mechanic didn’t tighten the caliper bolt

 

Pull the rear drums off look for any fluid on brake shoes.

 

Hey @KIMZJOI, did you ever figure out what the issue was?

 

This may seem silly, but the bleeder valve is at the TOP of the caliper and the feed line is in the midpoint right? Could the calipers be mounted upside down on the wrong sides of the truck? That would trap air in the caliper that would never come out no matter how much bleeding you did...
(Just read the entire thread because I just did my brakes and hate the spongy travel on the pressing of the 2nd gen brakes)

 

No flipping way that is normal... as many suggested master cylinder

 

I would approach this by replacing all four stock bleeders with speed bleeders. Bleed each one after install then take the truck to a sand/gravel road and stomp on the brakes a few times to activate the ABS system. Return to shop and bleed each corner again. parts are: rear = sb1010, front = sb7100.