Brake Problems on a 91 Ford Thunderbird

This thing should't be on the road.

The only advice I'll give you is to have it towed to a garage and let a mechanic fix it.

What are the chances of the brakes failing or not coming to a stop at all? Also what should I tell a mechanic to look for to fix?

What are you willing to risk? 10:1? 100:1? 1,000:1?

What if it's a kid that runs in front of you on a "bad brake day"?

Tell the mechanic that sometimes it won't stop well and the warning lights come on.

Beyond that, I can't help you. Don't drive it, is it worth the risk?

Good luck.

This is a highly complex and expensive system...not a DIY project.. Here is some info you might read to assist you in your efforts...

http://www.albeedigital.com/supercoupe/articles/abs-system.html

replace the rubber hoses that run from the chassic to the brake cylinders. i think the cords in a rubber line are broken. the brake line will expand "bubble" at the faulty hose and cause erratic braking. in some instances the brakes wont release because of the standing pressure in bubble. you will need a second man to observe the hoses as you apple pressure to the brakes. pump the brakes to make the broken hose expand.

That's always a good place to start, as well as flushing out lines and replacing brake fluid. Master cylinders typically either work, or they don't. On a 91, regardless of what the problem turns out to be, those flex lines should be replaced.

I don't think a spongy brake line will make the pedal hard to push. "the brake pedal gets really hard to push"

I agree that it would be a good idea to replace the rubber lines, but I don't think that's the root cause of the problem. Only the mechanic will know for sure.

i disagree lynn. if the flex hoses are expanding as the brakes are applied, the brake resovoir might be pumping all the fluid into the expanding hoses to the point where the vacuum booster is no longer effective.

That would run the master cylinder rod to full extension (with possible utilization of all fluid in reservoir) leading to flooring the pedal, not making the pedal harder to depress.

Anyway...expanding steel flex hoses? Under what amount of pressure and over what distance is this going to cause a noticeable loss of pressure in the braking system of a '91 Ford Thunderbird?

It's fine to disagree, even when you are wrong.

I hope you are not the same AP#1 who is infecting the bullet thread.

This may be the right track, given the vintage of the car..

I worked on a '73 VW Beetle years ago with similar braking symptoms (not ABS of course). The hydraulic fluid had apparently never been replaced, causing some reaction with the rubber...

Long story short, the hoses had swelled closed internally only, without showing any symptoms externally . Since the system was not power-assisted, I could literally stand on the pedal without any braking ocurring.

Moral of the story: drain and replace the brake fluid every ten years, taking that opportunity to remove and inspect the hoses.

Your caliper(s) isn'(aren't) working consistently.

The best thing to do is to replace the front rotors, calipers and pads. Probably cost < $100 per side.

Here's a Google search to get you started:

http://www.google.com/#hl=en&sugexp=ppwl&cp=22&gs_id=2e&xhr=t&q='91+ford+t-bird+brakes&pf=p&sclient=psy-ab&source=hp&pbx=1&oq='91+ford+t-bird+brakes&aq=f&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=943216f5c5580e8f&biw=1676&bih=826

Getting this taken care of will be of much greater value than the < $200 out of your wallet. Trust me!

Good luck!

Thanks for all the hint/ tips, really helpful. I'm not a mechanic that's why I've asked all these questions, I really did not know the extent of how serious it was. I'll call my mechanic and get it over there as soon as possible and will tell him what you all have told me.

Good luck, man

If your mechanic needs a few hints ask them to look at the ABS pump, pump actuator, and pump relay. Since you have warning lights, you will also have codes that need to be taken into account (that should be your first step).

I agree with most of what is written here, but I have worked on many of these units over the last few years and here to say - DO NOT DRIVE THE THING. You are endangering everyone on the road including yourself. Get it towed to a repair shop who does brakes. as you have several issues that will need to be addressed. Given the age of the unit and depending on where you are located, I might consider getting the 200-300 a scrap dealer might give you for the unit. Before putting 1000 into it. Your call!

GA

Best reply when reading from the top. (Only one showing some good accurate knowledge and common sense!!)

Good answer from you. Based on the information given, and the vehicle in question, I would also suggest that the OP check for dried oil accumulation in the pipe that feeds the vacuum hose leading to the booster. Oil breakdown was common in the 80s, and would clog the larger vacuum ports as the stuff would accumulate. Good luck.

Looks like you have gathered lots of suggestions. I would say many if not all have the possibility of being correct. Let's look at this in pieces.

Symptoms you mentioned:

1-Poor stopping with.hard pedal

2-ABS solid light

3-Brake light flashes

4-Brake light solid

5-age of most components

6- not mentioned but probably bad parking/emergency brake.

I will suggest that you consider 6 problems exist until proven not.

The ABS can cause some of the other symptoms such as the hard pedal so I would fix it first since that light is always on solid and would be easily detected as fixed. After that corrective action, recheck (in a safe place) your other symptoms.

Are there any other common conditions when the hard pedal and or the brake light is lit? Example would be when first starting to drive after setting for hours/overnight verses only after driven for 10 minutes or ten stops? Only when temperature is cold or hot? Has this only happened in the last week or has it gradually become worse over six months?

If you are not frequently working on brakes expect to replace any and all parts with functionality affected by wear, age, loss of lubrication or road hazard issues.

Your goal is to make the brakes work better than when the car was new, If you have any hesitation in doing the work yourself go ahead to a dealer or trusted repair shop. Try to tell them as many of the symptoms and related conditional observation.

My experience says for that vintage they will replace by whole unit swapping things like ABS unit, master cylinder, all hoses, flush brake fluid system and then go after pads, rotors, drums, shoes, wheel hardware and maybe some wheel cylinders.

You should first look up the prices for all those parts on the internet and have the list with prices in your pocket so you can judge that the cost quoted is reasonable.

ABS units can be tricky to do a whole unit swap because some cars need very specific steps to get them ready for street use. Read everything you can about the specific process for your year, make, model. New ones should come with directions but even then if the unit is used in other years and models, yours could be different than the memo-ed 6 language in box instructions.

Think ahead about the time to complete repairs by you and how long the car will need to be out of service for normal use.

Test that parking/emergency brake. Most will be non functioning from that cars vintage unless you have had it repaired recently or use it 2- 10 times a day.

Does the car have Rear Anti-Lock brakes only????? If it does I can probably send you in the right direction to get it fixed.

I think it might have four disc brake drums, I think that sounds right, but i brought it to a tire shop and they did a brake inspection, they told me my pads and routers or however you spell it where in good shape. Also there is no noise when I go to brake, no grinding or loud screeching noises, so im sure thats not the problem.

They are not called drums, they are called "disks", though some cars have a park brake in a small drum as part of the disk itself, in my experience usually on the rear wheels.

The disk is also called a "Rotor" by some shops in the USA.

You most probably have an air or vacuum hose problem for the servo (20 year old rubber), or the servo has a leak and or the master cylinder (sometimes the master cylinder and the servo are one unit, sometimes not).

Some years ago I had the same problem on a brand new VW (2001), it came and went!! 3 new servos did not fix the problem, but a new master cylinder eventually did!!! Almost 6 months of agro....

REALLY DANGEROUS.....the servo only failed when I drove well over 120MPH......legally here!!

I'm bringing it to a mechanic today, I've written down all what everyone has said and I will tell him what to look for. Hopefully I can get it fixed and if i can't it might be time to say goodbye to it. Thanks again for all the help.

Hello, Any update for us after being at the shop?

First be sure you know how the brakes on this car work. Several people have mentioned the power unit and I agree. But, is it vacuum or hydraulic. More and more cars are using hydra boost, which is powered off the power steering pump.

My '84 T'bird had a steady red brake warning light from time to time caused by a rubber silencer on the e-brake pedal being worn and not activating the switch. A few wraps of electrical tape solved that.

Like many others, I caution you to be very careful about driving the car until definite problems are found and corrected. -- JHF