[tennykimble]

95' sable, 3.0 engine, automatic 4 wheel abs & 4wheel disc brakes.

im pretty sure i need to replace the master cylinder on my 95 sable because sometimes when i stop the pedal goes kinda far down and it almost sounds like the abs motor is running for a VERY short amount of time. but it is not every time i stop -- BUT it is quickly becoming more frequent.

so my question is if i replace the master cylinder, do i need to bleed my abs system? i plan on bench bleeding the m/c before installation. i have a mac tools scan tool, but ive heard that i need a SPECIFIC scan tool to operate the abs motor for bleeding purposes??

 

[tennykimble]

bump

 

[Jeff K]

HCU only needs to be bled if the HCU itself is replaced. Just bench bleed the MC, and bleed the brake system as you would normally, and it will be fine.

 

[tennykimble]

thanks!

 

[tennykimble]

well... i put a new master cylinder on. and it didnt solve the problem. but it was pretty easy, i bench bled the master and put it on, and i didnt even need to bleed the brakes! the pedal was right on... better than its ever been. but it still tries to activate the abs sometimes when i apply the brakes... im wondering if i have a dirty ( or bad ) wheel sensor? i dont have any lights on the dash .. abs or service eng light. im gonna ohm each of them tomorrow to see if i have one out of wack?? what would happen if i unplug the abs motor -- i KNOW the abs wont work but it's kinda pissing me off that it keeps doing it!

any ideas??? thanks !!

 

[Jeff K]

Also check sensor to tone ring gaps to be sure they are in spec, and check the tone rings for rust / corrosion, missing pieces, plugged up with debris, etc.

I would suggest a full brake bleed even if the pedal feels better than it did. I cant believe zero air got into the system during the MC change.

 

[Stu Hadley]

how did this turn out? DId you have to do something special due to ABS?