Gotta love the brakes...

While getting ready for shootout, we decided to take all the tires off and check out the brake system thats been giving me issues. Ever since the motor went back in last month, i've been getting a constant hard pedal with steady ABS light AND brake light.

Today we replaced all pads and rotors, greased the studs of the mounting brackets and got all the bleeders to break loose. When starting to break the passenger rear loose, i got NO fluid.

Obviously something wasn't right so we turned the car on accessory and had someone listen for the pump motor to kick on. It turned on and turned off within 5 seconds, but when pressing the pedal down, I can't hear the accumulator ball recharge...Could the accumulator not be sending me enough pressure to get fluid to the rear? Or should I be looking for fuses and sensors. Also, keep in mind that I have a slight leak in the brake line that sends fluid to the rear coming from the proportioning valve but we plan on replacing the fitting tomorrow.

Ps. this is not my first time dealing with these teves systems and I think i've driven my car with bad brakes more time that I had with properly working ones...I try to keep them maintained but its very hard. I appreciate any input, thanks

A good accumulator will take more than 1 press of the brake pedal to recharge....

Press the brake pedal 5 or 6 times, then listen for the accumulator to recharge...

Do you have brake fluid coming from the drivers side rear bleeder....

That system also has only 1 line to the rear. This means if you don't get fluid on one side, it has to be the line going across from the drivers to the passenger side at the back. It could be a collapsed soft line at the caliper. Work your way backwards from the caliper until you get fluid. Also, first make sure your bleeder isn't stopped up though.

Ed- I will listen for the accumulator again today. We had the cap off the master last night and we were getting massive bubbles out from the back side of the resevoir with all the bleeders closed. When bleeding the system, the MC should be closed up correct?

Dave- When we were compressing the rear pistons in the calipers, we were getting fluid thru the bleeders but when we began to bleed the lines, nothing was coming out. I belive the last time we had issues, most of my lines were checked/replaced and there should be no damage that could've taken place to that rear line...

I'm thinking that our first step would be to fix the coupling on the line that goes from the distribution block to the rear...?

I don't ever remember getting bubbles in a reservoir. Sounds like something is goofy up front if you are getting air in the reservoir.

Again, there is only one line going to the rear of the car so if you get fluid on one side but not the other, then you have a problem in the rear of the car.

But none of this points to a hard pedal. If the accumulator is charging (signaled by the pump which slows down as pressure builds and then shuts off just before the point where you might think it's getting ready to stall out), then you should have a normal pedal feel and good clamping at least on the front, even if the rears are screwed up somehow.

I'm starting to think you have a bad master cylinder....

SCchick3 said:

Ed- I will listen for the accumulator again today. We had the cap off the master last night and we were getting massive bubbles out from the back side of the resevoir with all the bleeders closed. When bleeding the system, the MC should be closed up correct?

Dave- When we were compressing the rear pistons in the calipers, we were getting fluid thru the bleeders but when we began to bleed the lines, nothing was coming out. I belive the last time we had issues, most of my lines were checked/replaced and there should be no damage that could've taken place to that rear line...

I'm thinking that our first step would be to fix the coupling on the line that goes from the distribution block to the rear...?

Click to expand...

I've always bleed the system with the cap on the reservoir....

Was planning to drive my 91 to work today, but after firing it up I got out to disconnect the battery tender and close the hood while it was idling. About a minute later when I got back in the car I noticed the amber antilock and the red brake light were both still on. Backed the car out of the garage and drove it down the street...pedal was hard and I had very little braking ability. Prior to this morning the brakes have always worked fine and the brake and antilock lights always went out within a few seconds.

I read the ABS trouble shooting guide that Duffy put together (see link below), and it looks like the first thing I need to check is if the motor/pump is running. If it is running, can I assume it's a bad accumulator ? If it's not running, should I start by checking the ABS relay on the passenger side firewall ? Anyone have a picture of that relay ?

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

Thanks, David

David Neibert said:

Was planning to drive my 91 to work today, but after firing it up I got out to disconnect the battery tender and close the hood while it was idling. About a minute later when I got back in the car I noticed the amber antilock and the red brake light were both still on. Backed the car out of the garage and drove it down the street...pedal was hard and I had very little braking ability. Prior to this morning the brakes have always worked fine and the brake and antilock lights always went out within a few seconds.

I read the ABS trouble shooting guide that Duffy put together (see link below), and it looks like the first thing I need to check is if the motor/pump is running. If it is running, can I assume it's a bad accumulator ? If it's not running, should I start by checking the ABS relay on the passenger side firewall ? Anyone have a picture of that relay ?

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

Thanks, David

Click to expand...

David,

If the accumulator is bad, the pressure switch should pick up on that and make the pump motor run every time you step on the pedal, or even constantly. So I think there would be at least some braking assist. I don't think a bad accumulator would lead to a 100% hard pedal, all the time.

The relay is mounted on the firewall, below the BAP sensor, just to the right of the EEC self-test connector. You will probably need to unplug the gray fuel injection harness connector to get at it. If it is the original relay, it will be brown. In my 1990, it is the right-most of 2 relays.

David Neibert said:

Was planning to drive my 91 to work today, but after firing it up I got out to disconnect the battery tender and close the hood while it was idling. About a minute later when I got back in the car I noticed the amber antilock and the red brake light were both still on. Backed the car out of the garage and drove it down the street...pedal was hard and I had very little braking ability. Prior to this morning the brakes have always worked fine and the brake and antilock lights always went out within a few seconds.

I read the ABS trouble shooting guide that Duffy put together (see link below), and it looks like the first thing I need to check is if the motor/pump is running. If it is running, can I assume it's a bad accumulator ? If it's not running, should I start by checking the ABS relay on the passenger side firewall ? Anyone have a picture of that relay ?

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

Thanks, David

Click to expand...

If the motor is running but there is no pressure being pumped up, check the feed line to the pump,Sally's reservoir outlet was clogged with something--we had to take it off and blow air back through it ....the relay is the black relay with the brown base located near the firewall behind the passenger side front spring tower.....If you have a voltmeter, you can check the voltage being applied to the motor if it's not running....Dan

We also found that Sally's pump wasnt working as it should. The motor was fine but the pump was shot. Must have been from the lack of fluid getting to it due to the clogged line. After switching motors and pumps around and cleaning out the resivoir the abs light and brake light still came on. We switched out the accumulator and the lights went out. The only issue is that accumulator is on its way out due to the motor cycling after each press on the pedal.... Victor has new accumulators for 139.00... It could also just be your relay on the firewall and that is around 12-13 bucks.

Thanks guys...I'll see if the motor is running when I get home, and go from there.

David

Yeh the relay has a black top and brown base as Dan said. There should be a bracket on the passenger side firewall that they slide into. Not sure if you have two or three of them... If it isnt hanging there then it will be laying down in that area.

S_Mazza said:

David,

If the accumulator is bad, the pressure switch should pick up on that and make the pump motor run every time you step on the pedal, or even constantly. So I think there would be at least some braking assist. I don't think a bad accumulator would lead to a 100% hard pedal, all the time.

The relay is mounted on the firewall, below the BAP sensor, just to the right of the EEC self-test connector. You will probably need to unplug the gray fuel injection harness connector to get at it. If it is the original relay, it will be brown. In my 1990, it is the right-most of 2 relays.

Click to expand...

I'm getting some braking and a little pedal movement, just isn't anything close to how they usually work and pedal is noticably harder. I only drove it about a 100 yards and used the brakes 3 or 4 times after leaving the driveway. Felt about like using power brakes without the car's motor running.

David

If it turns out to be the relay, is that something I can pick up at Autozone or will I need to get it from a Ford dealer ?

David

ScrapSC said:

Yeh the relay has a black top and brown base as Dan said. There should be a bracket on the passenger side firewall that they slide into. Not sure if you have two or three of them... If it isnt hanging there then it will be laying down in that area.

Click to expand...

Anthony,

Is this black and brown one with the red arrow the ABS relay ?

David

Yes, that is the ABS pump motor relay.....

Check for power at the pump motor connection first...

A bad accumulator can cause a hard brake pedal condition....

As the accumulator wears out, the pump motor runs more often....

Over time, the pump motor gives up and results in a hard brake pedal.....

Is this the pump motor connection ?

David

Yes, that is the ABS pump motor connection.....

Red / grey wires are positive and grey wires are negative...

Tried listening to the pump to see if it was running and it's difficult to hear because of my transmission cooler fan and the remote mounted fuel pressure regulator. I went ahead and disconnected the pump connecter and it shows 11.7 volts, so the relay isn't the problem.

Plugged it back in and had my wife turn the key off and on numerous times while I held a screwdriver against what I thought was the pump motor with the handle against my ear. I can hear a click and feel a little vibration when the key it first turned on but can't say 100% the pump stays running, but I think it is.

I guess I'll try switching the accumulator and see if that fixes it.

David

Pull the accumulator off, then have your wife turn the key on for just a few seconds......

If the pump motor is good, you will get a 1" to 1½" geyser of brake fluid out of the top of the pump....

It will make a mess, but it will tell you if the motor is good or bad....