CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Brakes very soft - go to floor - nobody can fix

Brake travel is ridiculous and barely brakes at all until I get almost to the floor and then they seem fine. 2007 Ford Taurus 110k miles, bought a couple months ago.

  1. After buying took to mechanic and they flushed, new brake fluid, bled it, did nothing. They remarked the fluid was black. They couldn’t figure out what was wrong with it and I had some other problems with them and so that was the end of that.

  2. I replaced master cylinder out of fear, bench bled and it changed nothing. The seals on the old one seemed perfect as well.

  3. No visible leaks, have looked 3 times and two mechanics haven’t found any.

  4. The driver rear drum brakes fell apart a couple days after the original mechanic worked on it. The adjuster thing came loose along with a couple other small parts and I didn’t realize until I pulled the hub off the parts were resting in the drum. The drum is badly scored and the parts are ruined so I took them out and have left it since then. This also has not changed brake function whatsoever. I haven’t fixed this yet as I’m short on money and am more concerned about the pedal travel problem. I’m not sure if redoing the rear brakes would fix this as there is no adjuster at all in the one and I don’t know about the other.

  5. Brake fluid level has not dropped whatsoever after driving it maybe 50 times after replacing master cylinder and topping it off.

  6. Did brake booster test. If I pump brakes up with engine off it travels to the floor the first pump and then pumps up very hard and quick with second and third pump. I pushed as hard as I can and the pedal doesn’t budge at all. I started the engine and it depressed and went to the floor. It doesn’t pump up with the engine on it just goes to the floor over and over.

  7. When I brake very hard it pulls to the left a little at the end.

  8. The ABS seems to work just fine in ice the pedal shakes and it stops fine.

  9. I just took it to Les Schwab to have it aligned because I got new tires and the old ones wore funny. I talked to the mechanic and told him everything and I thought he said I needed to “bleed the brake booster” but after researching this doesn’t appear to be a thing? It’s possible I misunderstood him and he said it could “be the brake booster”. But after reading about that in general that doesn’t seem to match up with the symptoms I’ve read about. I also did the brake booster test as described earlier and it seems to be working fine. About 1 out of 12 websites I’ve looked at say a bad brake booster can cause the pedal to go to the floor but with my understanding of how it works that doesn’t make sense.

  10. I’m going to be taking it back to Les Schwab on Tuesday for the alignment appointment. I will also ask them to inspect the brakes and see what they say again… I was hoping to get help on here because nobody seems to know what the hell is going on with this car. I also would like to fix the problem myself if possible as I’m short on money and really need to get this done so I don’t die on the way to work.

Really appreciate any help, this has been a nightmare.

That’s because when the drum brake failed, your pressure problems started. And merely removing the parts from the drum did not fix the problem. :wink:

Service your drum brakes, both sides, and I bet you’ll be good to go assuming you don’t have a brake line leak somewhere, but you didn’t mention fluid loss so I’m guessing that’s not the case.

4 Likes

Are you absolutely sure you got all the air out of the master cylinder when you bench bled it? I’ve had to cycle those things for what seems like forever to get all the air out… If you still had air in the master cylinder when you installed It, its almost impossible to get all the air out of the system with a regular brake bleed at the wheel cylinders and calipers. BTW you don’t bleed a brake booster. and typically the symptoms of a bad booster are a hard pedal not a soft one. It sounds like you still have air in the system. I think you need to look for a better mechanic.

1 Like

Not sure if I understand you correctly, I probably didn’t make this clear but the pedal going to the floor has been a problem since I bought the car. The mechanic tinkered with it, I’m not sure if they actually took the drum off and looked at it, but a couple days after I heard various spring sounds and things clunking around. My guess was that he screwed with it and didn’t get a clip properly seated and it popped off when I hit the brakes.

Though if you think this could create the pressure problems then I’ll definitely look into doing the drums when I get the chance.

I also agree with shadowfax…You need to get the rear drums sorted out. Missing springs and things aren’t helping you out. The scoring of the drum isn’t really that big of a deal but if all the parts aren’t in there that is.

1 Like

I’m fairly sure it’s been bled properly. When I first bought the car the mechanic flushed and bled it, it was absolutely no different. Now I suspect they might also be incompetent so this is still a possibility.

However when I replaced the master cylinder I bench bled the hell out of it. It was maybe a half hour of pumping it until only a tiny, tiny stream of very small bubbles was circulating around. Once again it had absolutely no effect. I haven’t tried bleeding it otherwise at the tires though.

I’ve experienced air in a system before and the pedal was very springy and had some resistance before going down enough to engage the brakes. This one is not like that, it just travels to the floor with almost no resistance and then I get fairly firm brakes at the end.

If you trap the wheel cylinder pistons with C-clamps then bleed them the pedal should be high and hard if the problem is in the drum hardware. Give that a try.

2 Likes

Make absolutely sure the rear drum brakes have not had the adjusters installed BACKwards! That would give you a long pedal and it would get worse with each apply.

3 Likes

That’s a good idea, I think I can figure out how to do that.

A friend of mine had a similar problem with a Ford Tempo years ago. He had had a brake job done at the dealer and it worked fine for a while but the pedal kept getting lower and lower. He returned to the dealer twice, both times they adjusted the rear brakes and it was fine for a while then kept sinking closer to the floor.

The problem was easy to find as soon as I took off the drums, the left side looked normal but the right side had a shiny new brake adjuster in it. Unfortunately it was the wrong adjuster. The car had 2 left side adjuster, both clearly had L stamped in them, so every time he backed up the right brake unadjusted itself.

We forget because most cars have 4 wheel disc brakes how critical brake adjustment on the drums is to pedal height.

I don’t understand how you can drive around with the adjuster off without the wheel cylinder poping out and losing your brake fluid.

4 Likes

That’s a clever test… You could do that with the drums off and inspect visually for any leaks at the same time!
I’m putting that one in my back pocket in case I ever work on drum brakes again.
Its kinda hard to believe Ford would put drums on a car in 2007.
On a side note…I do know Ford used something called RABS or Rear Anti Lock Brakes on some models with drum brakes in the late 90’s… ( i seriously doubt if the OP’s car has this) but if it does, “RABS” had a separate master cylinder “of sorts” for the back brakes… mounted on the frame somewhere. It might be worth it to check and see if your car has this feature.

No way!!!

I just went and grabbed the parts that were loose in the hub, guess what is stamped on the driver rear adjuster, “R”…

You guys are sharp.

Good call by @oldtimer_11 above about the possibility the adjusters have been switched right/left. Sounds like that may be it provided the pedal is good at first, then after driving for a couple days the pedal starts to drop lower and lower. The physics of the way brakes work says the brake pedal can’t drop unless there is extra play somewhere in the brake system.

  • air bubble somewhere
  • rubber hoses are flexing too much
  • one or more of the movable parts of the system is not butting up against each other correctly somewhere

B/c everything is connected all together sometimes it is hard to figure out where the problem is. The suggestion above to clamp off some of the rubber brake hoses to isolate the parts can indeed narrow it down, and is the way many shops would figure something like this out. From there a visual inspection will usually sus out the exact problem. There is some possibility the clamping force may damage the hose though; you can’t make an omelet without breaking some eggs I guess.

Experienced diy’ers wouldn’t usually ever swap the right and left parts b/c they only work on one wheel at a time. But shop techs probably just work on brakes however they want, no particular order, b/c they do brake work all the time and know where the parts go. Except when they get a phone call and forget where they left off. Calipers can be reversed right/left too, which is often a difficult problem to spot. When that happens the bleed nipple points down instead of up, and makes it impossible to bleed the air out.

I’d guess even in 2019 there are quite a few cars, especially econoboxes, sporting drum brakes on the rear. Anybody here know?

Yep and @oldtimer_11 That was my first thought after having bled the brakes and replacing the master. Those rear drum brakes are not adjusted, but in your case they need new parts and adjusting. My 86 Buick Park was the last car I worked on with drums in the rear but on that one you had to adjust the shoes with a large caliper instead of the old method using a screwdriver. With the new ones they self-adjust when you back up and hit the brakes. Not in your case though.

That brake design looks very similar to the one used on my Corolla, which adjusts every time the parking brake is applied and released. My truck on the other hand uses a different configuration and self-adjusts when backing up.

These are the parts on the 2007 Taurus design that seem to have right/left configurations.

  • backing plate
  • parking brake lever
  • adjusting screw
  • adjusting lever

Yeah I really don’t know how they adjust, but I think his aren’t adjusting due to broken/missing parts.

The rear brake shoes are going to be way out of adjustment if the adjuster in in your hand and not installed in the brakes.

1 Like

I would say NEVER let that ‘mechanic ‘ touch your car again. Was the diameter of the drums checked? Until the rear brakes are fixed correctly and adjusted correctly you will not solve this problem.[quote=“veraxodium_146601, post:1, topic:132003”]

  • The driver rear drum brakes fell apart a couple days after the original mechanic worked on it
    [/quote]
1 Like

Just to clarify, on the Ford Tempo I cited, the parts were not swapped side to side, both sides had left hand adjusting screws, one original on the left side and a brand new one on the right. It is not unusual in our climate to have to replace these because once they rust so badly as to be unmovable, freeing them up would be only a temporary fix, the rust is too deep into the metal and they have to be replaced.

Mistakes like this are made by someone who has learned to replace parts buthas no clear understanding of how they work together.

Three things i would look into right off the bat… First I would be sure the new Master was PROPERLY bench bled and has no issues in that arena…

The next place to look is into the rear drums… Be sure they are adjusted correctly the self adjusters often don’t work as they should so you need to dial in the adjustment manually at least for the testing phase.

Another thing to check into would be the RUBBER brake lines… Make sure they are not “Ballooning” this is more common than you might think… But the Master cyl being bled is very very important…the next would be the rear drum adjustment and then the rubber brake lines.

I bet the solution lies somewhere among these 3 items.