Brake Problem

[Bill Liebbe 2]

I am having an issue with my 2003 Sport Trac. When apply brakes there is a moment of "give" just before you stop. I have changed the pads and rotters and bled the system. ANy ideas on what might be the problem would be appreciated.





Bill

 

[EddieS'04]

Did you loosen the bleeders? When pushing the caliper pistons in. Dont want to push the old fluid back into the ABS system.

 

[Richard L]

Bill,

Like Eddie said. Also, when was the last time you flushed the brake fluid? I mean, completely replaced the fluid. If you push the pistons back into the calipers without opening the the bleed valve, you pushed the old contaminated fluid back into the brake system and ABS. Even if you bleed the brakes, you are only taking out any air, and there may not be any, but the brake fluid also has attracted moisture and that moisture is still in the line. The heat from the brakes turns the moisture to steam which is a compressable gas.



I think what you are feeling is the moisture in your brake fluid converting to steam as you apply the brakes and then you are compressing that steam which gives you the soft pedal at the end. I would recommend flushing all of the old brake fluid out and replacing it with fresh fluid. This is done just like bleeding brakes except you will constantly have to keep refilling the brake fluid reservoir as you flush out the old fluid. Never let the fluid in the master cylinder reservoir run empty or you will get air into your master cylinder and that can be hard to get out...You sometimes have to remove the master cylinder and bench bleed it.



...Rich

 

[Scott Tanner]

+1 on Rich... :supercool:

 

[scott degroot]

Can you describe this "moment of give" any better. For some reason I think that you are trying to describe the abs activating when it isn't supposed to.



Do the brakes feel normal up to that "moment of give"??

 

[Scott Tanner]

Good catch I1tech... I get a little ABS momentary pulse on mine only when I brake and turn... Could give a feeling as the OP describes..

 

[Brad Schultz 2]

My ABS started to activate at almost a stop when turning, but now has progressed to wheels straight as well. Any suggestions on that one? Sorta feels like no brakes which Bill calls "moment of give".

 

[Jeff Ingram]

I had a simlar problem with one of my cars. I would hit the brakes and would start to slow, then it felt likes the brakes released a bit before finally grabbing again. Turned out to be the wheel bearings. They were getting loose enough that it was throwing off the ABS sensors that were built into them. Same type of setup that our Trac's have I believe so might be worth looking into.