Wet weather braking issue

**tesmith66** · 04-29-2011

Hi all, long time lurker, first time poster.

I have a 97 GP with the 04-up 12" brake conversion. I am experiencing the (apparently common) wet weather braking problem. I have to lean into the pedal for a few seconds at highway speeds before the rotors dry off enough to let the pads bite. I have been searching here and all over the internet trying to find a solution to this.

Is there a fix? My car has the flat 5 spoke wheels, btw. I am planning to give this car to my son when he turns 16, but want this problem fixed first.

Thanks.

**cerick08GP** · 04-29-2011

Yup, there is a fix for that, slotted rotors. This site bashes all day long on ppl spending a couple extra bucks on them, but the truth is they’re worth it. In fact my #1 reason for running slotted rotors was to fix the exact issue you have noticed. Both my GPs had a little issue with wet weather braking, and I had an Accord that was horrible. Nothing quite like the feeling of stomping on the brakes, and then have them actually start working 2 seconds later. Gives me a rush!!

Anyway, like I said slotted rotors are the only fix I know of. Just be warned there are “cheap” rotors out there, generally speaking you get what you pay for with rotors. I’m running Power Slot rotors, they are a high quality product FWIW.

**Bio248** · 04-29-2011

why would slotted rotors make this any different besides that they have a slightly better 'bite' on the pad due to the slots? the rotor itself would still be glazed over.

to me it sounds like your calipers are sticking a little and/or your pads are heavily worn. normally your pads graze over the surface of the rotor at a resting position so they should always be hot and ready to work.

**tesmith66** · 04-29-2011

I switched from ceramic pads to semi-metallic and it helped slightly. The pads and rotors are only a couple thousand miles old, so that isn't an issue. I was thinking that new calipers might help (pistons could be sticking a bit), but don't want to waste money. I have heard lots of naysayers putting down slotted/drilled rotors, but cerick08GP is actually running them and says they work. Pontiac used drilled rotors on the GXP, so they must have some faith in them.

Could excessive pad clearance, as in a sticking piston, cause this? I have replaced and cleaned and greased all of the hardware, pins, etc., but the calipers are original. Guess I'll rebuild those next.

**RyanL** · 05-05-2011

Originally Posted by Bio248

why would slotted rotors make this any different besides that they have a slightly better 'bite' on the pad due to the slots? the rotor itself would still be glazed over.

to me it sounds like your calipers are sticking a little and/or your pads are heavily worn. normally your pads graze over the surface of the rotor at a resting position so they should always be hot and ready to work.

if he says it has made an improvement then im gonna give it a try but with drilled not slotted cuz they look ugly lol. but alot of people have this problem like i do and my pads are not heavily woarn and the caliper piston moves just fine. so im doing the 12'' upgrade and gonna put some drilled rotors on them n see how it works.

**tcman49** · 05-06-2011

Originally Posted by Bio248

why would slotted rotors make this any different besides that they have a slightly better 'bite' on the pad due to the slots? the rotor itself would still be glazed over.

to me it sounds like your calipers are sticking a little and/or your pads are heavily worn. normally your pads graze over the surface of the rotor at a resting position so they should always be hot and ready to work.

The slots on a slotted rotor among other things, allows water to wash of the rotors quicker, ie via the slots which improves brake performance in wet conditions.

**Bio248** · 05-06-2011

but if the pads are not glazed over to begin with why would it be a problem with the rotor being mildly wet? it'll burn through it immediately when they come in contact with the rotor.

however, i've always been a big fan of semi-metallic pads because they just stop better. so what that they aren't as quiet and that they dust like crazy, they stop the car like they are supposed to. i've never been able to grasp why people would want ceramic pads unless they plan to run them for 100k miles and never touch the car.

**tcman49** · 05-06-2011

agreed

ceramic pads - long life, little brake dust but hard on rotors and sometimes emit noise.

semi-metallic pads - medium life, lots of brake dust, soft on rotors and certain types very quiet.

carbon metallic or premium semi-metallic pads - better than medium life, less brake dust than regular semi-metallic, soft on rotors, certain types very quiet.