Cycling ABS Module During Brake Bleeding
here's a thought about bleeding the ABS...
How about disconnecting one of the ABS wheel sensors and then while the car is on jack stands with the wheels turning, apply the brakes. This should in theory cause the ABS to freakout and start cycling the pump thinking there is excessive wheel spin. Might cause a CEL as well, but that can be cleared.
thoughts?
How about disconnecting one of the ABS wheel sensors and then while the car is on jack stands with the wheels turning, apply the brakes. This should in theory cause the ABS to freakout and start cycling the pump thinking there is excessive wheel spin. Might cause a CEL as well, but that can be cleared.
thoughts?
Having the same exact issue as the OP and others. Have bleed and rebleed the system over and over.Followed the how-to on here and referenced the FSM making sure the bleed order was correct. At this point I'm at my wits end with it. I'm so sick of putting the car on stands and removing the wheels I dunno what to do.
Same results every time with maybe a slight improvement in pedal feel. Like the OP, on stands I get great pedal then once back on the ground and moving it goes away. I must have pushed more than a gallon of fluid through it so far.
I guess my question is this: Has anyone came up with a definite way of getting the air out of the abs system, my positive this is the issue just not surre how to resolve it. Any input is appreciated.
Thanks,
Jason
Same results every time with maybe a slight improvement in pedal feel. Like the OP, on stands I get great pedal then once back on the ground and moving it goes away. I must have pushed more than a gallon of fluid through it so far.
I guess my question is this: Has anyone came up with a definite way of getting the air out of the abs system, my positive this is the issue just not surre how to resolve it. Any input is appreciated.
Thanks,
Jason
At one point I thought I did too and was considering removing the ABS module lines, then I talked to a few people and they had never heard of ever needing to perform that service. As soon as I bled the clutch it got rid of the mushy pedal I was dealing with.
Not saying you don't have air in your lines, but just want to make sure you've done the clutch before you start that messy side project...
Last edited by golgo13; Aug 22, 2012 at 12:55 PM.
How do you know you have air in your ABS system?
At one point I thought I did too and was considering removing the ABS module lines, then I talked to a few people and they had never heard of ever needed to perform that service. As soon as I bled the clutch it got rid of the mushy pedal I was dealing with.
Not saying you don't have air in your lines, but just want to make sure you've done the clutch before you start that messy side project...
At one point I thought I did too and was considering removing the ABS module lines, then I talked to a few people and they had never heard of ever needed to perform that service. As soon as I bled the clutch it got rid of the mushy pedal I was dealing with.
Not saying you don't have air in your lines, but just want to make sure you've done the clutch before you start that messy side project...

Air in the clutch line or old fluid can cause the brakes to be mushy, since it's part of the same system. Is that what your asking?
When I said messy, I was talking about disconnecting the lines to the ABS module in order to cycle fluid through it in an attempt to get air out of the system.
how would air in the clutch line cause the brakes to be messy?
The reason I think its air in the ABS block is because of this thread and several others just like it with people having the same problem. I honestly dont what else it could be as everything else is fine. No leaks, no piston binding etc..
And yes, disconnecting the line from the ABS module would be very messy, but at this point it may be my only option. Maybe just crack them open enough to let some fluid seep out. Hopefully that will be enough to get the air pocket moving.
Just a FYI, Montu on here had the same issue as OP. Long story short it was the brake pads that were causing it. Brand new pads must have had some defect. As soon as he put in the old pads his pedal was firm. I would re trace steps and put back the old pads and what not and see if that changes anything.
Air in the clutch system should not affect brakes. They share the same reservoir only.
A defect in the pad or rotor can cause squishy brakes, as the pistons can be pushed back into the calipers, requiring more pedal travel to make up theextra clearance.
Most likely the air is in the ABS, like mine was. You need a constant pressure of fluid (Motive bleeder) and open every fitting on the unit, and let it pour!
A defect in the pad or rotor can cause squishy brakes, as the pistons can be pushed back into the calipers, requiring more pedal travel to make up theextra clearance.
Most likely the air is in the ABS, like mine was. You need a constant pressure of fluid (Motive bleeder) and open every fitting on the unit, and let it pour!
I guess I'm one of the lucky ones too. I had all 4 of my calipers off for a month and did new rotors and hawk hps pads. I got the motive power bleeder, blead in order once, started the car, pumped the brakes for a min till it was solid, left the car running and performed the bleeding again, pumped the brakes one more time before I shut the car off, then blead one last time with the car off. Brake pedal is solid.
Also didn't know that the clutch fluid in the brake reservoir will stay there even though all brake fluid is drained and the clutch stayed solid even pumping it when all brake fluid was out. I didn't even need to bleed my clutch.
Also didn't know that the clutch fluid in the brake reservoir will stay there even though all brake fluid is drained and the clutch stayed solid even pumping it when all brake fluid was out. I didn't even need to bleed my clutch.
...it's all in the service manual.
step 1: bleed the MC
Step 2: bleed the lines/calipers with the engine running.
the ABS is self bleeding and is isolated from the system when not engaged so even if there was air in the abs pump you wouldn't know it until it engaged.
step 1: bleed the MC
Step 2: bleed the lines/calipers with the engine running.
the ABS is self bleeding and is isolated from the system when not engaged so even if there was air in the abs pump you wouldn't know it until it engaged.






