Strange brake behavior
#1
Strange brake behavior
Hi all,
I just replaced the front rotors on my '01 V70 T5 (80K miles). Everything seemed to go well - saw no leaks,etc. But after reassembly, I now have this behavior:
Engine running but car stopped: brake pedal sinks nearly to floor, but can be pumped up with 3-4 strokes. Releasing the pedal for just a second and this behavior is repeated.
Engine stopped: brake pedal sinks nearly to floor (as above), but only takes 1 stroke to pump up. Contrary to above, however, releasing the pedal and then reapplying the brakes after a delay does not show softness.
Its almost as if the power assist is causing then system to lose pressure.
Anyone have an idea what's going on?
Thanks in advance.
...Derek
I just replaced the front rotors on my '01 V70 T5 (80K miles). Everything seemed to go well - saw no leaks,etc. But after reassembly, I now have this behavior:
Engine running but car stopped: brake pedal sinks nearly to floor, but can be pumped up with 3-4 strokes. Releasing the pedal for just a second and this behavior is repeated.
Engine stopped: brake pedal sinks nearly to floor (as above), but only takes 1 stroke to pump up. Contrary to above, however, releasing the pedal and then reapplying the brakes after a delay does not show softness.
Its almost as if the power assist is causing then system to lose pressure.
Anyone have an idea what's going on?
Thanks in advance.
...Derek
#3
Could be caliper springs, yes...
But you didn't say if the pads were replaced as well; were they? New pads will seem a bit spongy until they seat in.
You also didn't say if it was braking OK? Have you driven it (carefully)?
Did you break open the brake hydraulics at all? If not, and the pedal was hard before then doubt it's a problem with the hydraulics. You've got mechanical play in the caliper(s) somewhere; double ck your install. Have you done brakes before?
But you didn't say if the pads were replaced as well; were they? New pads will seem a bit spongy until they seat in.
You also didn't say if it was braking OK? Have you driven it (carefully)?
Did you break open the brake hydraulics at all? If not, and the pedal was hard before then doubt it's a problem with the hydraulics. You've got mechanical play in the caliper(s) somewhere; double ck your install. Have you done brakes before?
#4
Hey, thanks for the responses so far.
Will check the springs tomorrow - any suggestions for finding a photo that clearly shows proper installation? My Haynes doesn't cut it.
Pads were quite new so I did not replace. I DID drive it around the block - braking was super mushy until 3rd/4th pump.
Nope, didn't crack the hydraulics at all - only levered back the pads to get the caliper off. That makes me nervous that somehow hydraulic fluid back-flow could have hosed something up.
I have done brakes once before, albeit on my Explorer.
I just find it strange to have this behavior at stand-still (which suggests this is not only a "seating in" issue).
Will check the springs tomorrow - any suggestions for finding a photo that clearly shows proper installation? My Haynes doesn't cut it.
Pads were quite new so I did not replace. I DID drive it around the block - braking was super mushy until 3rd/4th pump.
Nope, didn't crack the hydraulics at all - only levered back the pads to get the caliper off. That makes me nervous that somehow hydraulic fluid back-flow could have hosed something up.
I have done brakes once before, albeit on my Explorer.
I just find it strange to have this behavior at stand-still (which suggests this is not only a "seating in" issue).
#7
Whoa! Didn't think it was possible to put them on like that. Yep, definitely incorrect. Thank goodness you asked for help and didn't leave them like that. Now you know for next time...
#8
#9
#11
Ok. Thanks. I checked my brakes and the spring was installed correctly, yet I still have mushy brakes. I did notice that while the car is off I can pump the brakes a few times and they are solid and not mushy and stay that way while the car is off. When I turn it on it better, but still somewhat mushy. I did use a power bleeder to bleed the brakes last weekend and saw no air, maybe I should have just done it the old way and pumped the brakes. Boy, I am just at a loss here!
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mphilleo
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09-28-2013 05:59 AM