Brakes almost hit the floor and wont stop truck

the brakes on 95 toyota tocoma are soft and almost hit the floor and wont stop the truck , my first thought was the master cylinder was going bad so we changed it and bleed all the lines and back with the same problems . im leaning to a bad caliper but every thing looks good so far no leaks every moves good as far as i can tell . truck has 200 plus on her pads seem to be in good shape , just dont want to pay a shop and no i can do it myself if i no what part to change and dont want to throw parts at it as ive already did with the master cylinder please help

You might check the load compensating valve on the rear axle.


Did you bench bleed the master before installing it?

Did you bleed the brakes with a diaphragm brake bleeder and the appropriate adapter?

Even if you had one bad caliper, that wouldn’t cause these symptoms. The other 3 calipers would stop the car and the brake pedal wouldn’t go to the floor.

Usually this is a master cylinder with bad seals.

so yes i did bench bleed the master and pretty sure thats all good , what would be the diaphragm brake bleeder and what is the rite adapter

so i did change the master already and thought that was the problem, and i’m back where i started, but 50$ in the hole. ugh lol. should i continue to bleed the brakes which i believe i’ve done properly? i don’t believe it’s a caliper, but what else could be my problem?


The two man brake bleeding method is not as effective as using a diaphragm brake bleeder.

I believe this is the right adapter.

BA10 or BA11 is the one for you

I personally own the master set and use the adapters all the time at work. Much easier to use the adapters versus finding a buddy and coordinating the two man effort (pumping, holding, release, etc.)

what is the load compensating valve and how do i do that does it have a bleeder on it cause i did bleed that also if were talking bout the same thing , it located over the rear axel and a part of the rear break lines correct …?

so ur thinking i still have air in the lines and that was the problem before from a leaky master


What I am saying is that there MIGHT still be air and old nasty brake fluid in the lines

ok thank you im pretty sure the lines are clrear of air but well not 100% other than that i dont knows whats wrong with the soft brakes besides calling the new master is bad and get another one

@o4dodgediesel That is why I suggested you do the brake flush again, using the pressure brake bleeder and the adapter.

It’s a lot less work than removing the master, putting it back in the box, returning to the store for an exchange, driving back home, bench bleeding the new master, etc.

Maybe you do have a bad new master, but I’d want to be absolutely sure there’s no more air or old brake fluid in the lines before heading back to the store

I think @db4690 is on the money. With this symptom, if you’ve already tried the manual bleeding method, and there are no visible leaks, the next thing to do is a pressure bleed. In some cases that is the only reliable way to get the air out of all the nooks and crannies, without damaging something else in the process. If that doesn’t work, then return the new master cylinder as defective, and get a new one. The caliper’s seals can leak too, but in the kind of calipers I have experience w/at least, that would almost always cause a visible leak of brake fluid dripping down the tire. Did you get under the car and look at the inside surface of all 4 tires and brake backing plates, checking for signs of brake fluid? The master cylinder generally leaks internally and produces no visible dripping of brake fluid when it fails. This is frustrating, I understand, but it has to be done right for safety.

ok, george, i’m in the sc mountains, so i’m guessing we are close by. the brakes seem to have no leaks, but if i’ve replaced the master and have the same problems. doesn’t that say it’s not the master and a leak that i’m missing or some other problem, as i’ve done nothing but spend 60$, and nothing has changed. my reservoir is not new. could that be my problem? but there are no leaks from that, that i’m sure of.

the brakes on 95 toyota tacoma are soft and almost hit the floor and won’t stop the truck. my first thought was the master cylinder was going bad so we changed it and bled all the lines and back with the same problems . i’m leaning to a bad caliper but everything looks good so far, no leaks, even moves good as far as i can tell . truck has 200 plus on her pads, seem to be in good shape , just don’t want to pay a shop and know i can do it myself if i know what part to change and don’t want to throw parts at it as i’ve already done with the master cylinder. please help

It is also posible to have a bad flexible line at one of the wheels.


Here’s some more ideas:

Put the truck on 4 jackstands
Remove all of the tires
Remove the rear drums and carefully inspect the wheel cylinders for any signs of leakage
Carefully inspect the caliper piston seals for signs of leakage (especially in the folds)

Have you inspected the rear shoes and adjusted them?

Not necessarily o4dodge. I doubt there is anything wrong with the plastic reservoir as long as there are no visible leaks there. Provided you had a normal pedal before, and all the slack has already been adjusted out of the drum brakes (if your car has rear drums), here’s what I think is most likely happening to you:

  • The new master you purchased and installed is defective; or
  • The new master you purchased was fine when you installed it, but you’ve subsequently damaged it; or, more likely,
  • The new master is fine, but you introduced air into the lines when installing it, the air has found some nooks and crannies somewhere in the system to hide, and you haven’t been able to eliminate it yet.

If I had this problem and didn’t want to take the car to the shop for a pressure bleed, and didn’t want to invest in the pressure bleeding adapter, what I’d do is simply bleed the brakes manually a few more times, making sure to use freshly purchased brake fluid of the type the manufacturer of the car recommends (usually “Dot 3”, but check your owner’s manual to verify, or phone up a dealership and ask them). When doing a manual bleed, I get best results by having a helper open the bleeder valve for the wheel I’m doing, then I very gently (with my hand) press the brake pedal about 3/4 of the way to the floor, but stopping before I reach all the way to the floor. Then the helper closes the valve, and I very carefully and slowly allow the pedal to rise. It’s important not to allow the pedal to rise too fast. Then I wait a full 30 seconds for any air to equilibrate before repeating the opening of the valve and pressing of the pedal. There is a theory that you should press hard on the pedal during this process to force the air to the end of the line. For me this doesn’t work and make the process harder to get the air out. Definitely do not pump the brake pedal.

Make sure you start with the longest brake line, and work your way to the shortest. Every make/model/year is different. The shop manual for the car will usually recommend the wheel order to do this. If I take my time and do it sort of scientifically like this, it has always worked. But sometimes I have to go through the process several times, after waiting a day or more in-between. For me manual bleeding it has always eventually worked, but takes quite a bit of persistance.

One other thing. Some vehicles are more difficult than others. My Ford truck with drum brakes all-round for example is simple to bleed. But I had a 70’s VW Rabbit one time, and the way the front disc brake calipers were situtated when they were bolted on their mounting, it was virtually impossible to get all the air out w/manual bleeding. The only way I could get the remaining air stuck in the caliper out was to remove the caliper from its mounts, and tilt it this and and that so the air would go to where the bleeder valve was. Situtations like that is where the pressure bleeding can make things easier, as the pressure bleeding can get the air out in most cases without going through this kind of gyration. Best of luck.