01 XJR, 140k miles. Time for my first brake job and I've come to notice that the brakes are REALLY bad when its raining out, especially on the freeway. Obviously they're getting wet and the pads and rotors are definitely in need of replacement, but I'm wondering if there's also something else at play here. I beleive I saw that the XJR (maybe the XJ8 to) has air channels built into the front end to cool the front brakes, which is a nice design touch, but I'm wondering if there might be something missing from mine that is supposed to keep water out of those channels or something, or if its normal and I'm just really noticing it lately because my pads are just worn that far down.

I do know that I'm missing the plastic cover that is suposed to cover the bottom of the radiator, the front bumper cover has a bunch of the tabs that it would screw to broken off, so I don't think I could get one to stay on securely without swapping out the front bumper cover, does this possibly answer my question or should there be something I might be missing in the air channels that would help prevent water intrusion?

Along the subject of brakes, I have the standard 325mm rotors in the front, wondering if its worth my while to purchase Brembo products...not the R1 brakes, but Brembo brand factory sized rotors and pads. Any sense in spending extra for slotted rotors? Would that help my wet brake issue or maybe it'll just go away with the new hardware? Costs seem comparable to the cheap stuff at Advance and Autozone, so I don't really see much of a downside here...is there? Maybe a beter question, is there an upside?

Thanks!

 

Hi to my fellow New Yorker.

I have an identical spec car as your . I used to run EBC pads and upgraded goodridge steel brake lines on my non Brembo set up. the result is noticeable and very comparable to R1 performance.

regarding the rotors, I will leave to some one to discuss.

 

My first question would be which tires you’re running on - and at what pressure - and what condition they’re in…

 

I have never heard bad brake power when wet with disc brakes. Drums in otherhand are completely different story. I've driven with disc brakes with very very cheap pads(on a different car), pads that fade from one hard braking and still had no issues with water and even with slush.
My x308 had some whatever pads all around and those were good. Without any issues in the rain, heavy rain allso. I replaced disc and pads and selected ebc greenstuff pads. Way better brake feel and grip and still no issues with water.
Is there any friction material left in pads ? How much greenstuff pads with repaired calipers increased brake feel and grip I don't think you have need for Brembo option from 325mm discs that you have when driving in the streets or better roads.

 

Thanks Vincent! I'll have a look @ EBC.

Currently on my snow tires, they're in excellent condition, lots of tread. Pressure is 32-34psi. Car tracks straight and true and I am 100% not hydroplaning or anything of the sort. When I'm driving on the highway in the rain I have no issues following the road, changing lanes, etc. What happens is I need to hit the brakes and while the pedal feels normal, I have little to no braking performance for a very brief period of time...during which time I'm assuming the pads are boiling off the thin coating of water between them and the rotor. The left front grabs an instant before the right front, but apart from that little intial pull to the left I have full control of the car's direction and I quickly learned to keep a longer distance when its raining.

ABS, stability and traction control never activate when any of this is happening, so I don't beleive this is a loss of grip but rather a moment of significantly decreased friction between the pads and rotors. Hopefully its just worn pads and rotors, but wondering if there is something else at play which is directing water onto my brakes that I need to correct while I'm pulling things apart.

 

I've had that on a bike in the past. Seemed to be a mix of discs & pads that didn't play nicely together when wet as fitting new pads sorted it. Neither pads or disks were particularly worn & indeed they did it from when fitted, but I put up with it for a bit to see if it'd improve. I've also had similar when using 'fast road' pads as they got too cold when wet, so needed to warm up before they bite which took 100yrds or so at times.

If you don't know what pads are in it currently, I'd try some new ones to see what happens. It's a cheap enough option before getting too involved in fancy ideas to resolve it.

 

EBC doesn't seem to offer greenstuff pads for the XJR, or at least not the 325mm front rotors, so its either redstuff or brembo pads, brembos were far less expensive so I opted for the cheaper option today. Just to clarify because when we say "brembo", we all usually think Brembo upgrade R1 package...I'm buying Brembo branded pads that are OE replacements for the standard brakes on the XJR. I'll probably grab some brembo OE rotors as well down the road, but I don't think I need them at the moment...pads are more time sensitive.

Thanks all!

 

Look forward to hearing that that gets things back to running - and stopping - the way that they should!

 

Yes they do offer. Pad is the same with 305 and 325 discs. I had to fiqure this out too.
I bought
DP2689/2
DP21198
And I do have 325 discs.

 

Thanks Vauxi, good to know!