What's wrong with the brakes on my 1999 Lincoln Navigator?

My Navigator’s brakes were subtly pulsing when I stepped on the pedal, sort of like a slightly worn brake pad, but just barely noticable. I changed the pads and checked the rotors and all seemed fine, but the slight pulse when I slowed persisted. Then I noticed my ABS light on in the instrument panel, and a couple of days later while turning around at a gas station, my brake pedal went to the floor with next to no resistance. The brakes engaged only slightly and I was able to limp it home at about 5 mph. There is no fluid leak and nothing appears worn. Do I need a new master cylinder or ABS components? I’m a little lost. Thanks for any help.

You need to take it to someone who knows how brakes work. A worn pad does not cause pulsation. I suspect that your first problem was warped rotor(s). The other problems could very well have been caused by any mistakes made while changing the pads.

Have the vehicle carried to a mechanic on a flat bed truck. It’s not safe to drive. The mechanic will figure out what’s wrong. If the ABS light is on the mechanic will scan the computer for trouble codes.

Please don’t drive this vehicle until it’s been repaired.

No mistakes were made changing the pads; it’s a simple 2 bolt process that I’ve done a dozen or more times in the 26 years I’ve been driving and working on cars. None of the rotors are warped.

I would never continue driving a car without adequate brakes. The gas station where they failed was very close or I would have had it towed even then. My problem is a financial one; If I could afford to have it towed to and seen by a mechanic, I most likely wouldn’t have attempted to solve the problem on my own. Without further suggestions, I suppose I’ll just change out the master cylinder and hope that solves the problem. I just didn’t want to spen the money on a new or re-built one, put it on, and then the problem persists. That’s why I asked for advice. Thanks.

Throwing parts at a problem when you have no clue what is wrong makes little sense. The ABS system and failure light compounds the problem… Lots of moving parts, many of them failure prone, all of them expensive. And somewhere on that vehicle you DO have a slightly warped rotor or bad wheel bearing…

Then surely you don’t need our help.

Surely I do. I assumed the advice I would get would be from someone who has experienced or repaired a similar or exact problem. Not simply, “take it to a mechanic.” Unless that is my only option, it’s not particularly helpful. If it is my only option and no one has ever repaired a similar problem on their own, then thanks.

“My problem is a financial one;”

Let me get this straight. You’re driving a Lincoln Navigator, but you have financial problems? Is that correct?

A Navigator is a huge, thirsty vehicle that sucks gasoline as if its free. And now that your Navigator is not working correctly you want us to pity you. What’s wrong with this picture?

You don’t know what’s wrong with it, and neither do we. That’s why we suggest you take the vehicle to a mechanic. You can keep spending money, and throwing parts at the vehicle, or you can take it to someone who knows what he or she is doing.

If this were my vehicle I’d take it to a mechanic. I learned a long time ago that I was not an expert, and I was often wasting money fixing things that didn’t need fixing. I know my limits. When those limits are exceeded I gladly pay a professional mechanic to fix my vehicles.

Take the vehicle to a mechanic. You’re unlikely to fix this yourself.

You have received some good professional advice. It is always cheaper (and in this case a lot safer) to find out what is wrong before trying to fix it.

You certainly have a problem with rotor (or maybe a wheel bearing). My guess is you have at least two problems, maybe three. I can’t see hear feel or otherwise test from here. Since the various problems may or may not be related and may be sending confusing (mixed) messages, you need someone who really knows what they are doing put hands on your car to determine what the problem(s) are.

Often we can offer advice that you may be able to test and repair yourself. Usually the symptoms are not so confusing and complex. That along with a very real safety issue, is why we are all saying you need to have it taken to a local pro.

I’m not sure what business it is of anyone’s or how it’s relevent to a car repair forum, but the Navigator used to belong to my mother who gave it to me last year for christmas. I DID NOT ask for pity in any sense of the word, I asked for advice on fixing my brakes. I assume most people who post on forums such as this are attempting to fix their own car’s problems on their own. If you are comfortable speaking for every other contributor to this forum, “You don’t know what’s wrong with it, and neither do we,” that’s your prerogative. However I’ve posted several questions in the past to other forums and gotten answers from people (some mechanics) who tackled the exact problem I’ve inquired about and given me spot on repair instructions, so I thought I’d try again here. If you do not know, do not reply to the question. If you know, but realize it’s too complex to fix on one’s own, suggest a mechanic. But to just shrug and say take it to a mechanic is not helpful.

I do not know, and I will not reply again.

Best of luck to you.

Thank you, you answer was very helpful.