looking for a good WORKING used ABS unit
They are a little hard to find... Sure your's is bad???
Most of the time hard pedal is due to a bad relay, fuse link or even the ign sw.. If the car stops OK but has the amber anti lock light, possibly could be a wheel sensor wiring, or relay....
I have no rear brakes, no fluid getting to the rearend assuming its the abs unit plus a hard pedal
It got to here somewhere? Got to be the one on the left becuase the one on the right says ride control. I also have all four sensors lower in the picture. Have no idea if it bad or not, was on the car and the brakes worked fine (1987 TC). Don't know enough to tell you if this is the problem or not.
What is it worth?
TED
Ted you have the computer(s) and wiring, but he is talking about the actual master cylinder..
88turbo, I'd be checking into the electrical side, before I'd go replacing it. Does the pump run(humming noise from the M/C) when the ign sw is first turned on?? If not nine times out of ten its the front relay(there are two) on the firewall just to the left of the M/C assembly.
I think I checked all of the wires with the key on and I didnt find any power, I'll look into those relays, you said they are on the firewall just to the left of the master cylinder assembly? I'll go look and see if I can find them.
this what your talking about? and is there any way to test these?
Sorry, when he said ABS unit I thought he meant the computer. I may have everything else (master and pump) in a couple of weeks if he still needs it. Have to make sure I can stand the manual brakes.
Your right, when you step on the brakes a couple of times you should here the pump running. Or pump the brakes a couple of times before you turn on the key and you will hear it then. I bet it is the reley. You could jump a wire across it and see if the pump runs then. You can't over pump it, it will turn off when pressure builds up. The pressure switch is built in right at the pump.
Isn't there a valve that turns off and on the rear brakes? Normally it's open but the computer tells it to close when needed. This would be part of the master cylinder.
Where would this board be without you, TurboCoupe50? You have been a great help to me in the past, thanks.
TED
is it possible that my rear brakes are stuck closed? ABS is all new to me I have no idea
Sorry 88Turbo I should quit now, I also have a lack of know how. Is the pump working?
TED
havent bypassed it yet too dark to do anything, do you know wich wires to jump across?
I just went out and looked for you. Mine is pretty open right now.
There are two relays. One has a grey base and one is brown. The brown one controls the brakes. (I have no idea what the other does, maybe fuel pump?)
If you take it loose from the fire wall there will be room for 5 wires i the bottom but only 4 are there. The heavy one on the side by itself comes directly from the battery and should be hot all the time. If it is not it has a fusable link by the starter solinold that might be burnt. This would be my first test, is this wire hot?
On the other half of the bottom are the other three wires. The heavy one goes to the pump. You would jump the two heavy ones to bypass the relay. Do not do this as a permament fix, sure to run down your battery and burn something out. Only a test.
The center wire goes to the key and this is what makes the relay work (this is the short one in the picture that I cut off becuse I thought I did not need it). When you turn on the key this should be hot. In turn it will make the big wire next to it hot also. I not sure what the third wire is, maybe a ground?
I hope this helps. Please ignore the wiring mess, work is in progress.
TED
Ted that sums it up... Good info there....
well I got the pump to run, but I still cant get fluid to the rear... is the pump supposed to run continuosly when you turn on the key?
No it will run till it pumps up. It should also has a 20 minute protection built into it, if it does not pump up by this time it will shut down and will not run again for up to 10 minutes.
Turn it on and wait the two or three minutes and see what happens. If it does shut down, pump the brakes a few times and see if it starts up agian pumps up and shuts down, if it does it working OK and you have other problems.
Make sure your fuild is full.
Good Luck.
TED
I have been reading through the shop manual for you. The section on ABS T-bird is 110 pages long and most of it might as well be in a different lanuage.
Page six says;
Bleeding the rear rakes requires a fully changed accumaulator or they must be pressure bled.
Note: If pump motor is allowed to run continuously for approxmatley 20 minutes, a thermal safety switch (inside motor) will shut off motor. A 2 to 10 minute cool down period is typical befor normal operation can resume.
Once accumulator pressure is available to the system the rear brakes can be bled by opening the rear brake caliper bleed screws for 10 secounds at a time while holding the brake pedal in the applied position with the ignition switch in the RUN position. Repeat until an air-free flow of brake fluid has been observed at each caliper. Pump the brake pedal several times to complete the bleed procedure. Adjust brake fluid level. Warning, care must be used due to the high pressure.
Page 5 says;
Malfunction of the anti-lock brake system will cause the electronic controller to shut off. However, normal power assisted brakeing remains. Malfunctions are indicated by one or two warning lights inside the vehicle.
Front brakes can be bled in the conventional manner, withor without the accumulator being charged.
I hope this helps. I think the bottom line is if you do not have pressure in the accumulator you are not going to have rear brakes.
TED
so if I cant get pressure in the accumulator do I need to replace it?
With my limited knowedge, I would say you are back to the first post.
TED
well thanks anyways.
If the pump runs with the relay jumped, you've basically found your problem...
This system can be a pain in the ass to bleed... I use a small hand vaccum pump to pull the fluid through the system.
it almost seems that if I ground the relay with the key on it makes the pump run. is the pink blue stripe wire the ground? if so I need to run a better ground. what kind of vacuum pump do you use? where can I get one? when we tried to bleed the brakes today all we got was a few drops.
The relay is mandatory for proper operation, need to check with one of the auto parts stores(or dealer) for a replacement...
This is a pump similar to what I have...
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92474
replace the pressure switch.
go to http://www.lincolnsonline.com/article21.html
it says,"the pressure switch is located under the master cylinder,inboard,tilting up at about a 30 degree angle,six inches or so in front of the firewall.
anyways it states at the bottom of the page that the person who wrote this article has owned and operated his own brake shop for 14 years.hopefully this helps.if you cant find this info,just reply and let me know.i would be willing to type in the whole article,if i had to,to help someone out.
also check out http://www.lincolnsonline.com/article119.html
I have a complete assembly out of a 87 turbo coupe. worked when I pulled it out.
can you get these at any part store or is ford the only place that has them?
Did 87-Turbo get you the part you need? If not I have mine out now.
Now I know why they are fairly rare, they are a bitch to get out. The manual makes it sound so easy.
TED
I guess the only part that I am needing is the pressure switch. mine will run if I jump the relay. or maybe it just needs a relay :dunno: