i bought my car about 1 year ago and previous owner deleted the ABS.
so during the last few months I sourced all the parts to re-install it; abs pump, ecu, 4 sensors and brake lines that run along the firewall.

i had everything installed but the abs light on dash came on. the front drivers side sensor didn't work that well on the voltmeter when i spun the wheel. so i got a new used one and just installed it and now the abs light is no longer on the dash. i am very happy about that. it gets good numbers when i spin the wheel too.

test drive:
i still lock up the wheels. i just beat the crap out of the car. still locking them up. i'm not even sure if i felt the abs pump on the brake pedal. why would the abs not work and no dash light go off? the fuse is good (the ac light still goes on if i push it). could the abs pump be bad?

thanks.

 

Are you sure you properly bleed the brake lines? Air in the lines will affect the response of the ABS.

On another front, do you have factory rubber hoses on the lines coming off the fire wall (i.e., the brake booster)? There are important check valves in the factory hoses.

 

keeping in mind that the ABS pump was completed removed and re-installed, do i have to bleed the ABS pump separately? will air in the pump make the abs not work, or just make the brakes feel spongy?

but to answer your question, the brake lines were bled (just not the abs pump).
not quite sure what you mean in your second sentence though. pics?

 

you know those two relays on the pump. one is called a motor relay and the other is called a valve relay. ray at malloy quoted me $36.38 for the motor relay and the valve relay is $68.19. which is way cheaper than my local dealer. but why are these two relays so expensive? anyone know where to get the specs on these so i can get them from a non-mazda source?
i just wanna make sure they aren't the cause of my issues.

 

I've read, you must bleed the brakes with the ignition ON, so the pump is open...I've never removed or installed and ABS pump, so I can't stand behind that statement.

 

i wonder if normal relays with same post configuration would work instead of the OE ones

 

Some brake specialist may be able to tell you how to bench bleed the ABS controller, but when I swapped my original controller after the seals began to leak, I do not recall doing anything special to bleed the controller separately. I may have turned the ignition on as Dubulup suggests to be sure the controller was flowing fluid through the unit.

 

I hit someone cause the ABS system SUCKs REMOVE it!

 

KBS, what did you do with the system you removed? hook me up with those two relays on the abs unit.

i'm gonna search on bleeding with the abs...

 

Hey guys... ABS system should work if your wheels are locking. If you have air in the system, its trivial for now. Also, if there is air locked within the module's secondaries, it wont escape until the first actuation. Low tech way is bleed brakes as normal, actuate ABS a few times, rebleed. Thats if you can actuate the ABS.

Since there are no ABS lights, then that means that the ECU is seeing all sensors... now I am doubting the module is being seen since its not working... are you sure you hooked up the module power OK? Im confused why this wouldnt throw an ABS light though if you didn't. The only other thing is that the ECU isn't correctly connected to the HCU (vehicle is talking to the ECU, but ECU actuations to the pump/HCU arent being executed).

The other possibility is that you have really fooled the ABS calibrations w/ different wheel/tire combos.... Most ABS systems do a startup routine on keyon (havent confirmed the rx's)... if it does this(abs module vibrates during keyup), then you know the ECU is talking to the HCU/pump.

 

well i just checked the two relays on the abs unit and both worked fine when powered up as per the manual.
since i no longer have the abs light on in my dash (since replacing drivers front wheel sensor), i'm just gonna give it a good bleeding with key on. thanks and will keep ya posted...

 

i just did another test drive.
brakes still lock up.
no abs light on dash.
i unplug one sensor and the abs light on dash lights up.
i plug it back in and light goes off.
i tested both relays; both are good.
one of those relays (one closest to firewall) has a loose cover; i lift up the loose cover and push down on the copper thingy and i hear the pump work.
this makes no sense to me.

 

means your conrol device isn't communicating with the pump. Does the accumulator in the pump/mod assembly build system pressure when you turn the car on? You may want to check the signal wire between the comp and mod. Also, the comp output circuitry could be bad even though it isn't throwing a code for the wheel speed sensors.