1990 cadillac fleetwood
Contents
Question
Hi it is me again regarding the 1990 Cadillac Fleetwood. You said not to touch the round container next to the master cylinder that it was for the abs system(i think). We need to find information on how to change the hydro boost and master cylinder because everything is connected together with the black round container. I bought a book but it sucks. Is there any place on line that can help us. Thanks again for all your help.
We believe it is the hydro boost because half way down the line we get fluid to the rear breaks but then it stops and we can't get it out of the rear breaks. Plus when the car is turned on the book says you should hear the hydro boost kick on for about 2 minutes but there is no noise from the boost.
Answer
Hello,
Hydraulics for the braking system and hydraulics for the hydro boost are 2 separate issues. The booster is only for brake assist and not for fluid to get to the rear. The metering valve controls fluid to front and rear brakes.
From what I remember, you had at one time had the master cylinder empty. This could have uncentered the metering valve which controls fluid to front and rear. You also had to fill the power steering fluid for the hydro boost which one has to ask where did it go? In the unit causing it to fail. 2 different issues and you need the service manual to sort it all out.
Did you try the old fashioned way of bleeding the rear brakes instead of gravity? Did you open the bleeder have someone step on the brakes to see if fluid would come out, tighten and repeat? The brake assist has to be fixed first so you can tell if the pedal will go down properly in the first place without effort.
If you fix the brake assist (hydro boost)that only controls the amount of pedal pressure for stopping and has nothing to do with brake fluid pressure. You have a 21 year old car which makes it difficult (not impossible) to obtain decent repair information. If this was a 2005, you could go to http://www.alldata.com and download a service manual for $30. Because of its age you are left with only one other option. Try Ebay or Craigs list to see if you can obtain a factory service manual for the car.
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Question
QUESTION: My brakes were working fine then I turned off my car to replace a fuse for the windshield wipers I started driving again the brakes are working but they are really hard as I press on them. I have to press them with everything I got to make the car stop. I had the fluid checked, the brakes bled but they are still doing it. The car was given to me after sitting for almost 4yrs. The master cylinder was bone dry when I got the car. The brake light is on and also the anti-lock light came on. Hope you can help.
Also my dash lights(trip meter,gas gauge, speedometer) wont work. The radio won't work and neither will the heater. They did work and now they wont. The headlights work, the windows work, dome lights work but all the digital dash lights will not work. Thanks for any information.
ANSWER: Hello,
Wow! Lots of questions for different problems and I can help you, but we need to do these one at a time if that is not a problem. Your brakes-the answer on that is simple. A hard pedal is usually caused by one thing. A bad break booster. I don't remember the style on your Caddy if it is vacuum operated ant the back of the master cylinder. (Huge round disc with a vacuum line going in mounted to the fire wall). If you have this style, you need to make sure the booster is getting vacuum at the line with engine running. Pull the line off and see if there is sufficient suction. If there is, chances are the booster is bad.
There is another style GM used known as "Hydroboost" and it is mounted closer to the left front frame rail. The power steering in essence runs the hydroboost. A loose belt can affect the stopping ability of the car. If equipped with this system, check your power steering fluid level and fill it up if low and if you have this system and if you add fluid, assist should work fine.
As far as the anti lock system, you will need to take it to a service center (not the dealer) and install a hand held scanner to get the diagnostic code for the problem. The light being on is only a symptom and not the problem. The scanner will tell the tech exactly why that light is on.
As for the electrical--You need to consult with the owner's manual first and find out if there is one fuse box or two. Then you need to look for the gauge fuse. If blown, that should take care of your lighting problem.
As for the radio. Again could be a fuse, other wise you will need to pull the applique (wood grained plastic bezel. Look or screws, but I believe just snaps and you grab it evenly and pull outward. Check for screws though). There are only 2 power wires (3 if you count illumination). One for switched (ignition on). Another from the cigarette lighter and dome light for radio memory) After you remove bezel there are 4 9/32 or 7 mm (same size) head screws. Remove and pull stereo straight out. You can use test light at connectors to see if you have switched power on one of those wires on the back of the radio. If not, you may have to run a new wire if the fuse is good. If you do have power, you can check the black ground wire, by grabbing a 12v power source and touching the black ground wire with only a test light. If light comes on, ground is good and you need a new stereo. Go after market. I hear where in Dallas there is a commercial from an electronics store offering an after market stereo installed for $99.
As for the brake light. I wonder where all that fluid went from the master. It should have not been dry from sitting unless you have a wheel cylinder or caliper leaking. I recommend bleeding the brakes. Loosen up the right rear bleeder first and let it squirt the air out of the line. Make sure you keep filling master when doing this. Then the left rear wheel and tighten lightly or you will break off the bleeder screws. Go to front. Loosen caliper bleeder. Tighten, and loosen remaining bleeder and when straight fluid is coming out, tighten. If you do this on a driveway, just rinse with water and the fluid will be gone. Now, the metering valve should be self-setting and brake light should go out when engine is started and brake pedal is pumped a couple of times. Brakes are always a concern and I would recommend after you bleed the brakes, you have all the seals checked out by a professional. You might get a bonus and anti lock might go out as well. Hard to say.
I am also concerned why the wiper use blew.
I don't like cars that sit for years because rodents like mice and squirrels like to make their home in these cars, commonly under the hood to chew up wiring. I have seen that a lot. Didn't know if I could answer all your questions at once, but I guess I did.
You did not say where you live. If you are in one of those rust belt states like Wisconsin, you are going to have a problem with rusty bleeder screws and they will snap off on you and then a tech has to gently try to apply heat to them without burning the rubber in the wheel cylinders and calipers. I got good at it because I lived in Wisconsin for over 50 years, but if in question, don't try yourself. Very dangerous if not done right.
Good luck and please, let me know the outcome. I would really like to know.
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---------- FOLLOW-UP ----------
QUESTION: Thank you so much for your help. My car is a 1990 Cadillac Fleetwood. I live in California. I got the dash lights, and the radio to work. Since you recommended the gauge fuse and it was fine I decided to change them all. It turned out to be the body computer/radio mute module. I noticed however a couple of the fuses don't want to stay in(one of them is the wiper blade fuse).
My question is I don't know what type of brake system I have. Looking up diagrams I came across one that said it is an electric power booster. It does have this black container next to the master cylinder, not finding a round disc mounted to the fire wall. So my question what do I do now?
ANSWER: Hi Connie,
The black container s for the anti locks. Leave that alone! Hydro boost is a large rectangular box with steel hydraulic lines attached that run to the power steering. It is mounted to either the driver's side inner fender. I can take a picture of a hydro boost in my suburban tomorrow and I can take a picture of the round vacuum booster of the Lincoln tomorrow. Chances are if you don't have the round part behind the master, you have hydro boost. At least you will have pics to tell. Did you check the power steering level? If empty or low, you will have no brake assist.
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---------- FOLLOW-UP ----------
QUESTION: I did check the power steering fluid, it was empty when I first got the car so I filled it up and the level of fluid has remained the same. We tried bleeding the breaks as suggested, we are unable to get anything out of the back breaks. Fluid does come out of the front but nothing out of the back. I don't have money to take to the shop right now so I am trying everything I can to do this on my own. I have attached a picture as you can see maybe this will help you with what I am saying. Thanks again for you help.
Answer
Hello,
Pic helped greatly. You have what is known as hydro boot. Not real happy with it because don't know it that good. Worked on them in the 80's on diesels and hated them. My burb has hydro boot assist as well. That is your hard brake issue. The system has to be functioning correctly. You might have some air in the hydraulic lines. Look for a bleeder screw on it. you can find one, crack it open. Put a pan under the car. See what condition fluid is in. should be clear or red. Not black.
Tighten. ill power steering res. Use power steering fluid or dexron III trans fluid.
Start engine after filled and turn wheels right and left. Don't stick your hands in front of engine when running. Booster may possibly be bad.
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