Suddenly No brakes question

I have a 2000 Tacoma. It was down for a few weeks due to replacing a front bearing and all ball joints. Get it all put back together and take it for a test and all brakes are gone. Goes to the floor like nothing is there. Reservoir is full, no visible leaks. Tried bleeding it. Fluid to 3 wheels for sure. No luck. Any reason it would just suddenly lose all brakes while sitting? Thought about the master cylinder but hate to keep buying parts I don't need

 

I’d bleed them again with a power bleeder. They’re fairly cheap and easy to use. Here’s a thread from this page, if you aren’t already familiar with them.

https://www.tacomaworld.com/threads/motive-power-brake-bleeder.685032/

 

Can you build pressure at all by pumping the brakes?
Like when bleeding them? Does pressure build?

Does the pressure drop as soon as you start the truck?

 

No. I can't get any pressure at all. That's what I'm not understanding. Nothing at all. All pressure disappeared while sitting. Zero resistance on the pedal. It's like it's not building pressure any

 

Either you have air in your lines, or your master cylinder isn’t holding pressure or has a little air pocket in it. I’d bench bleed the master cylinder as well as the lines again. I’d suggest the power bleeder again because you’ll be changing those brakes again and the cost will be worth it.

 

not tht you did this
but
kid neighbor knocked on my door one time....did similar work FE work.....same problem...asked me to take a look
i saw his front pads on the tool bench....he forgot to re-install pads

 

Have you looked in the cab for brake fluid?

 

Till you get fluid to all 4 wheels it'll never build pressure, IMHO

 

You should be able to crack open a bleeder valve at one of the cylinders.....
pump the pedal and should shout out....

If not then rebleed the master using a master bleed kit......or use a couple your own hoses....
that is your last chance.

You bleed that throughly and still get no pressure at a bleed point.....
then your master is shot....

Plenty on line vids on how to bleed in place ,or bench bleed a master...


90% of time its air in the master.....

 

There's fluid pouring out of the calipers when I loosen the bleeder or the line on the calipers. I don't think it's building pressure. Can't seem to get any burps of air. Guess I'll get a master cylinder and see if it helps. Never dealt with brake problems much so not sure how to narrow it down

 

I did compress one caliper with a clamp to get it over the rotor. Could that damage the master cylinder? I've done it multiple times on multiple vehicles and never damaged anything

 

I did it when I replaced the brakes in mine... it shouldn't fry the master cylinder, though. Is it good for it? Probably not. But what you're saying definitely shouldn't happen. I would follow this guy:

My only other guess (which its 99% chance it's not), is your brake booster blew out the master cylinder when you started your truck, but I would listen to @O'Silver_Taco

 

Yeah I think my brake booster just failed, or at least in the process.

Sometimes the truck wont start unless I pull and plug that vac line.

It is going to a PIA to swap all that out........so I dang sure want to make sure thats the no start.

Its only because of the threads here I knew to check that 28 yrs old original booster...

it was the last easy, stupid thing you can check....without tearing into major stuff...


I figure that check valve is not closing at startup, or there is a leak in backside booster diaphragm..

That leak is causing -5 FT at idle, jumping to +10 at cruise....

Must be flooding more air at start than the ecm can compensate for....

Reason any major vac leaks.....equals start and idle problems...