chrisw

iTrader: (2)

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?

sr20det91

iTrader: (59)

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

golgo13

iTrader: (134)

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 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...

teribble

iTrader: (31)

how would air in the clutch line cause the brakes to be messy?

golgo13

iTrader: (134)

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.

sr20det91

iTrader: (59)

I dont think it would either because its a completly different chamber in the MC. Besides that I have bleed the clutch as well and its solid as a rock.

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..

sr20det91

iTrader: (59)

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.

teribble

iTrader: (31)

Sorry auto correct owned me. I meant to say mushy.

TommiM

iTrader: (19)

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.

blknblubkrdude

iTrader: (16)

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!

golgo13

iTrader: (134)

It must have just been old fluid, since that was the only variable that changed in my particular case.

sr20det91

iTrader: (59)

Good suggestions on the pads and rotors, however in my case they are the same ones I had been using previously with no issues.

blackgsx01

iTrader: (17)

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.

sr20det91

iTrader: (59)

You just mentioned something I havent tried yet and that is bleeding with the car running. Dont really know what difference it would make, but I'm gonna try that next.

griceiv

iTrader: (2)

...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.