Hi everyone,


My 2004 Supercharged XJR has been having some problems I hope you all can help me solve. First, I have a loud grinding brake noise when I come to a stop. It does it more when I come to a slow stop. I have changed the front rotors and pads already. Second, there is a moaning/groaning sound while driving. The car drive fine but the sound is very noticeable. I think maybe it's the supercharger and I plan to change the fluid this weekend. Third, The radio changes stations, or should I say bands (AM to FM,) on its own. Has anyone had any of these problems? Some insight would be much appreciated. Thanks in advance.

 

Hi joeleerj,

From your description, I assume the grinding sound is coming from the front?

How recently did you replace the rotors and pads? If you did the work recently, I would suggest double checking to ensure that everything was reassembled properly.

A caliper that is not releasing properly can wear out a pad much more quickly than you might expect, so if it's been a few months since you replaced the rotors and pads, it's possible that one pad has been worn down to metal.


Moaning and groaning are terms often used to describe the power steering system when the fluid is low, so it would be worth checking your P/S fluid.


Sorry I can't help with this one, but mhamilton has been inside his X350 radio and may be able to offer some ideas.

Cheers,

Don

 

The rear brakes wear can quickly on on these owing to sticking calipers; particularly the standard ( non Brembo) ones, and the noise can travel the length of the car making it difficult to establish whether it's from the front or rear, without visual inspection. Usually the caliper pins can be eased back to life, and sparingly lubricated with cv point grease to help prevent recurrence.

 

Thanks for replying Don B,
yes the grinding sound is coming from the front, and it only happens if I come to a slow stop. I've checked and re-checked my assembly of the rotors and pads and they are correct. I think I may have to repair the pistons, as I think you may be correct in stating that the calipers are nor releasing properly.


I used a 60cc syringe and suctioned all of the PAS fluid from the tank and replaced it with fresh fluid, I also purchased and installed some PAS fluid additive today, but I have not performed the procedure described in the Tech bulletin as of yet. I'm praying that fixes my problem.


Have not Idea about the radio problem.


Thanks

 

Thanks for the response Etypephil,


I have Brembo brakes and I'm 100% positive that the front brakes are the culprits. I stood outside the car while my wife applied the brakes and the front sounded like metal on metal, but the rotors and pads are only a week old.

 

So from what I can discern, you replaced the brakes a week ago and now get a grind when you apply the brakes. You stood outside the car while your wife applied the brakes and you confirm it happens only when the brakes are applied and not when the car is just rolling forward/ backward?

If the answer to these is yes, do a quick fingernail check on the rotors. I assume you also isolated which side, but in any event run your fingernails from the hub outward to the end of the rotor. Do this on both side of the rotor. If the Caliper is locked and you're grinding as described, you're likely cutting into the rotor and a quick fingernail check will isolate, which caliper is locking up. You will be cutting grooves into the rotor, much like a vinyl album but (hopefully) no grooves at all.

Also recommend you jack one wheel up at a time and just spin the tire and listen and also brake while spinning.

Here a TSB regarding light creaking but that doesn't appear to be what you're describing.

If it were me, I would disassemble and reassemble the brakes, but not sure if you're a DIYer.

With regard to power steering, You can drain and replace your fluid with ATF fluid and your P/S moan should go away. The additive should work, but if it doesn't, ATF fluid if cheap and there's nothing special about the P/S rack. Others may weigh in.

 

Thanks Sean W,
I've checked the rotors and they are not grooved, additionally, I have brembo brakes and the TSB doesn't appear to apply. However I did apply grease to the pin on the brembos'.

 

Here's another thought: If I recall correctly, the original pads installed in the Brembo calpers on our XJR had arrows on their back surfaces indicating the direction of forward rotation of the rotor. I believe the OE pads were made by Ferodo. The replacement Mintex pads I used did not have arrows and seemed perfectly symmetrical, so I installed them without worrying about the direction. Is it possible the brand of pads you installed were supposed to be installed in a particular direction?

Yet another thought: I can't remember, but if either the inner or outer pads have bent steel noise-making "wear indicator" tabs, is it possible that those tabs are supposed to be installed the opposite way of how you installed them, either at the upper or lower end of the inner or outer pad when it is installed?

Please keep us informed. This is very intriguing!

Cheers,

Don

 

Thanks, I'll check that out this afternoon.

 

I will also inform when I find the solution

 

Don is correct about the directional pads as the arrow points toward rotation. If slotted rotors were used, they are also directional, as are the calipers FYI. I assume by your comments you checked these though.

If there is a cricket, aka squealer, aka wear indicator, it's attached to the outer pad and on the bottom, so if you have it on the inner pad, that could be your problem. I'm fairly certain the OEM Brembo's didn't have a wear indicator on them but if yours do, you know how to apply now if you didn't already. Sorry, I no longer have the car or I'd check and confirm.

 

I have had a scraping sound when braking and turning and coming to a slow stop.

The noise was due to corrosion on the edge of the rotor touching the caliper.

Because it only happened when I was breaking AND turning, I assumed that under

those conditions there was some flexing going on.


Removing the corrosion from the edge solved the problem but

the edge of a new rotor must be very near the caliper.

 

Yes I have checked and they don't have directional indicators or squealers. Thanks

 

Thanks for the input meriion1,


I have brand new rotors and pads and I thoroughly cleaned the calipers before assembly. I think I may have to rebuild the caliper to solve this problem. I have already ordered a rebuild kit and new pistons.

 

[QUOTE=joeleerj;1558354]Hi everyone,


" My 2004 Supercharged XJR has been having some problems "

Regarding the front brakes , was the noise there before you replaced them ?

 

It was twice as bad before I changed them. Plus, the rotor was warped and I changed them as well.

 

Hey Joe, sounds like you bought aftermarket pads? Brembos have directional markers. If you don't mind, share the brand and part number and I'll be happy to research them (directional or not) for you.

 

Thanks Sean W,
the pads are Wagner #MX938, and the rotors are PAGID #355123092.

 

Still looking for Disc info. Nothing on PAGID's Website even list the part number.

Here is the break in formation on the Wagners

Tech Tips | Expert Automotive Repair | Wagner Brake

I see no reference to them being directional. Sorry

 

Thanks for the info. I bought the rotors from Rockauto.com