more brakes

capsfan88

Registered User
Hi guys, brakes seem to be the hot subject right now so here's my problem. I noticed a noise coming from behind the dash when I was in the car. It turns out it is something in the accumulator area. If I just turn the key on the accumulator/resevoir is buzzing/vibrating. If I start the car the niose cycles on and off. If I tap the pedal the noise stays away. The fuse is VERY hot. If I take the fuse out the noise stops. This brake system is about the only thing I haven't worked on yet. Any suggestions?
 
hi Capsfan, Your gonna need to be a little more specific. Are your brakes working fine? Are you getting the antlock or brake lights coming on? Flashing lights with a touch of the peddle? Just a guess from what you have said, I think you may need a new accumulator. If your pump stays on all the time then it may be something else. Just let us know and we can awnser almost all your problems.
 
If you go and touch your accumulator when you hear it buzzing, you will probably feel it vibrating. This happened to me and I never did find out exactly what it was. I theorized at the time that it might be a sticking valve, so I went out and found a gravel road and did a few quick stops to cycle the ABS. After doing this a few times, (about 10), the buzzing finally went away.
Worth a shot.
 
Brakes are working fine(I haven't tried a panic stop yet for fear of the ABS not kicking in). No lights on the dash during braking. I'll find a place tonight and try some hard braking.
 
Well, the brakes just quit! I didn't get a chance to test them any further. I applied the brakes while pulling out of the parking lot and the pedal wouldn't move. She's goin' up on the rollback any minute now. :mad:
 
Sounds like either the pump motor, or the pump motor relay has gone out. The relay is a low cost part, the motor is not. I'd try the relay first. Someone will post the part number for you soon, I'm sure.
 
There are 2 relays. One is for the anti-lock computer, the other is for the abs pump motor. I believe the pump motor relay is the brown one.
 
I have that relay out and I get continuity across the coil but nothing across any of the contacts. I will replace it monday and hopefully be done. Thanks for the replies.
 
I replaced the relay and it didn't help. The pedal is still rock hard. How much is a rebuilt unit from Prior(they were closed when I called)?

Any idea what voltage I should see at the motor?
 
I have a brake problem too, I dont know where to look for the relays where on the car do i look to find the relays for the brakes, they worked the other day then just quit, i went out yesterday and i had brakes till i tried to move it so i dont know what to even look for i have a parts car but i dont want to start unbolting inless its nesicary
 
They are mounted on the fire wall on the passenger side. There is one relay for the abs pump and one for the abs control module. The module itself is located on the accesory tray in the trunk. Good luck('cause I'm not havin' any!)
 
capsfan88 said:
I replaced the relay and it didn't help. The pedal is still rock hard. How much is a rebuilt unit from Prior(they were closed when I called)?

Any idea what voltage I should see at the motor?
Hmmm.. You should be getting 12V at the pump motor with the key on. If the relay is working, you'll see it. Did you say the motor continuity was OK? If so, try jumpering the thing to the battery for a second or 2 and see if it does anything.
Prior has the rebuilt HCUs for around $400 I think. Its definitely worth a phone call. If its not the motor, and its not the relay, the only thing left is the pressure switch. They can be found somewhere, start with Ford and see if you have any success with places like Partsamerica.com.
 
What would suggest i check on mine i dont have any brakes i replaced the relay and i dont know what to do now???
 
The pressure switch is on the hydraulic unit. I believe its under the brake fluid reservoir. It has a set of 5 wires connecting it. You can test it for continuity also. Let me see if I can help out..

If you shut the car off and pump the brake pedal a dozen times or so to be sure its depressurized, then you should see continuity between pins 3&5, 1&2, 1&4, 2&4 of the part in the hydraulic unit, not the wire harness itself. In particular, pins 1,4 are the switch for the pump motor relay. If 1->4 is zero ohms, then the relay should engage the moment you turn the key on to the run position, and the pump should run. You don't have to start the car to check this. If you see an open circuit, theres your problem. Try tapping on the unit with a hammer and see if anything changes.
The connector has a Grey, Pink/Liteblue, Tan/Red, and 2 other wires whose colors are blurred on my wiring diagram.

Now, if you turn the key on and leave the connector off, you should see 12V on pin 4 (pink/Ltblue) of the wire harness side and 0V on pin 1 (grey wire). pin1 of the harness goes directly to engine ground, so a continuity check to the negative battery post should be 0 Ohms.

Hope this helps.
 
Brakes

Ok i told you ive replace the relay and the computer, what me and a buddy that owns a shop is we ran a direct feed from the battery and we couldnt get the motor to run that way(incause you were wondering yes i did also ground it out to,) so the motor should have ran but i couldnt get it to run so im going to try to replace the motor not quite sure if it is posible but ill try,
Ill let you know im just trying to give you some hints on how to fix or trouble shoot yours
 
I've done alot of troubleshooting on this thing. Here is where I'm at. With the system depressurized I turn the key on and get no voltage at the motor harness. If I ground pin 4 of the pressure switch harness the motor runs. I put everything back together except for the pressure switch cable and ran a wire from pin 4 to ground and drove the car around the block. Brakes were great. I take it this means the pressure switch is bad? Where can I get one and how hard is it to change that sucker( I had a hell of a time just getting to the connector to unplug it!)?
 
Has anyone changed the pressure switch with the unit still in the car? If so, how tough is it to do? I had a hard time just getting my hand on the connector under there.
 
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