ABS/Brake indicators flashes w/ braking...not the accumulator...I need help please!

metalman

Registered User
So, I read that when the ABS and brake indicator lights flash under normal driving conditions, it means that the accum. is bad. My pump motor also turns on with every step.

So, I replaced today with a spare that I know works, cause I just took it out two weeks ago.
Yesterday I replaced my whole brake unit and bled the brakes. The brakes feel fine under normal braking conditions, but when I slam on my brakes I feel like I'm fighting against the unit a bit, the tires will lock up (ABS doesn't work) and sometimes I pull to the left.

Any other thoughts as to why my pump motor kicks on with every step of the pedal and indicator lights on?

It would be most appreciated!

Metalman
 
metalman said:
So, I read that when the ABS and brake indicator lights flash under normal driving conditions, it means that the accum. is bad. My pump motor also turns on with every step.
Sounds correct.
metalman said:
So, I replaced today with a spare that I know works, cause I just took it out two weeks ago.
How did you conclude that it was good? With accumulators, age is the wear factor, not mileage. If the spare accum was used, it should be replaced, especailly if its more than 8 years old.
metalman said:
The brakes feel fine under normal braking conditions, but when I slam on my brakes I feel like I'm fighting against the unit a bit, the tires will lock up (ABS doesn't work) and sometimes I pull to the left.
Yup.. points to a worn accumulator still. Your accum does 2 things: Give you power assist to the brakes and power reserve to cycle the ABS valves. When they get tired, you can still have brakes that work fine but not enough reserve for the ABS. When they keep aging, eventually you loose power assist.
Best thing is to get a brand new one either from Ford or prior. Check the supplier links out. :)
 
The Accumulator is responsible for storing hydraulic pressure generated by the hydraulic pump in the ABS master cylinder. (Assuming a 1989-1992 SC car, 1993+ are different)

The accumulator fails when the nitrogen gas inside it leaks out (which it will do as the rubber bladder containing it ages) it's ability to store hydraulic pressure is reduced. As it's ability is reduced, this requires the hydraulic pump to run more often.

This accumulator was needed in this system to provide brake assist during sudden panic type stops. The hydraulic pump is unable to respond fast enough to maintain assist by itself.

So as this fails you will typically see the ABS light come on and a loss of assist immediately during a panic stop type event. If the Hydraulic pump is working properly, and the system is full of fluid, the ABS light and assist should come back on quickly after it went away as the pump catches up to what your foot is trying to do.

That is the typical failure mode of the ABS Accumulator. If it doesn't recover quickly, or the brakes pull to one side or another, you may have a bad accumulator, but that is not likely the only problem you have.
 
Not to say anybody is wrong here as it sounds right to me,
BUT.... what if the lights are flashing a code?? Lets just say the right rear ABS ring is damaged, or the ABS Comp not getting the correct info, or some other malfunction. Could this cause the ABS to lockup the tires??

...you "fighting the ABS during panic stops" is what it feels like when the ABS is "Purging" the pressure to keep the rears from locking up. Fix whatever is wrong before you burn up the ABS Pump. Trust me.....this is not fun. :(
 
Usually, like the Firm light on the ARC, the ABS will flash the antilock light after the startup self test and anytime after if it detects a problem. The brake light would stay off in that case as it is controlled soley by the pressure switch and fluid level switch. The ABS system doesn't even know that the brake light exists and vice versa :) So, if you see both lights cycling after the initial startup period, then that would point to a common element in both the main hydraulics and the ABS which is usually the accum.
 
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Thanks for the tips guys!

Anthony.

I now found one more problem :mad: It's now leaking fluid around the pump motor housing. I took it apart before installing it becuase of a clog in the housing that the pump motor screw onto/the accum screws to/the pressure switch screws onto. I am thinking I need to get on the pump motor screws a bit more but at this point...who knows! Factory torque must be extremely tight.

Do you know the torque required from the pump motor screws or the pressure switch? The torque needed seems to be "tight as hell"

...or maybe I should just change to the 93+ ABS system!?!?! :confused:

Thanks again guys
 
Might not be pump seal

metalman said:
...It's now leaking fluid around the pump motor housing. ..........Do you know the torque required from the pump motor screws or the pressure switch?
Make sure it is not the pressure switch as that's what I thought too until I got it out of the car. A leaking pressure switch drips onto the pump motor and dribbles down around where it seals. GM has a pressure switch for like $80.00. Tell them you have a 1988 Buick Reatta WITH ABS (Teaves Mark II). Same switch @ 1/2 the cost IF Ford still carried it.

Someone correct me...like you wouldn't anyways :p .... but I didn't tighten mine up that much as I think I read somewhere that it isn't much torque on those...like maybe 25 or 30 Ft-lbs.

Aren't these fun brake systems??? :D
 
Well, I broke down today....

and bought a freakin' $50 pressure switch socket :eek: I figured, if I'm have consistent problems with my unit, I will do what it takes to fix it correctly. I called ROTUNDA, the company that makes the specialty tools for FORD.

Ya know all those special tool numbers in the Ford manuel.
The number is 1-800-ROTUNDA if anyone needs it.

I'm also gonna buy a new accumulator too. Hopefully this will fix my problems.

Metalman
 
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