Guys, I purchased a set of used stoptech BBK st60 and st45 from a fellow member about a month ago. The car stops great when the road its dry, but tonight when I drove my car in the rain (it was pouring), I almost crashed into the car if front of me on freeway. What happened was when I tried to hit my brake, the peddal seems very soft (never happened when the road it's dry), and it took 2 to 3 seconds before the car starts to slow down. Can anyone tell me what could cause this, I'm afraid to drive my car now, and the raining season just started.

 

Tires?
Hydroplaning?

 

Tire only had 10,000 miles, and its still in great condition.

 

Sounds like tires

 

Is the pedal not "soft" when it's dry?

 

Is it a soft pedal or your just not getting any brake bite. It sounds like no pad bite, pedal don't just get soft in the rain.

My bet is pad compound, same problem with my bbk in the rain.

 

ZPHILE, my pedal is hard when it's dry.

Terrasmak, I felt like my brake pedal is floating on something and the car doesn't want to slow down for couple second, then my brake pad start to bite down to the rotor. It felt like there's something in between the pad and rotors. What did you do in the end to fix this?

 

That would be your pad compound causing that. Change to a more street friendly compound.

I don't care on my car, i just brake early and smooth in the rain.

 

Normally the pads will be close enough to the rotor to keep water from getting in the contact area. You may have excessive knockback, and that's letting more water in. That would account for the soft feel and delay in braking.

Check the runout and unevenness on the rotor, and check the bearings for excessive play while you're there.

 

My brakes are soft if it's pouring out and I haven't used the brakes for a while.

 

What pads are you using OP? Not sure I ever experienced this one before..

 

I'm not sure what brand was the pad, it already came with it when I got the kit. The seller told me it was the original stop tech pad that came with it when he brought it.

Now I did put some anti squeal sticky silicon compound on the back of the pad, that might pull the pad away from the rotor when I release my brake pedal, which might let excessive water got in between them. I will take them apart this weekend, and try to remove the compound. Thanks guys

BTW, how do I check my bearing while I have my wheel off my car?

 

Yes remove the anti squeal crap.

Check the pad compound, but this is a common problem with running large cast iron rotors. Any time i also wash the car it takes a few for the brakes to work properly, because the pads transfer layer on the rotor affected.

 

From the '07 service manual:

WHEEL BEARING INSPECTION
Move wheel hub in the axial direction by hand. Make sure there is no looseness of wheel bearing.
Axial end play : 0.05 mm (0.002 in) or less
Rotate wheel hub and make sure there is no unusual noise or other irregular conditions. If there are any
irregular conditions, replace wheel hub and bearing assembly.