2008 xj8l front brake light rattle. Goes away when brake pressure applied

 

My apologies on the spelling, first attempt on this forum. Experiencing a low speed slight rattle. Dealer mentioned in could be the front disc pad retainer clips. I replaced but still experiencing. When I apply a light brake pressure the rattle is gone. Pads appear 50% life left. Thinking of replacing rotors and pads.

 

It used to be possible to fit sticky "anti-rattle" pads to the back of the brake pads to cure this problem.Did you inspect the assembly for looseness anywhere when you replaced the retainer clips ?

 

It's could be the rotors warped or uneven wear.

 

+1 on this.

Swapping parts is not my idea of problem solving. Remove the rotors and take them to a tire shop to ensure they're true. You should confirm looseness and Fraser suggests.

 

Sorry for the delay in response. Thanks all.

Sean seems to have been on the wrong track.

The rotors had been turned a couple of times. I replaced rotors, new pads and hardware, cleaned and problem completely solved. Back to silent, smooth and improved braking. The deep rattle that is now disappeared seemed so much like a suspension issue.

Whew.

 

Glad you got it resolved. It would have helped to know the rotors had already been turned in your original post.

 

I am also having an issue that sounds/feels very much like suspension or steering - annoying clattering sounds when passing over a tiny bump or pothole, ripple, etc. Reminds me of driving over a dip while towing a trailer. I noted in another thread that the noise was occurring both before AND after replacing the front struts with Arnotts.

I also noted that it may have started shortly after I replaced the pads and disks on both sides - but that just seemed so unlikely, having done dozens of those in my lifetime, doesn't appear to be much that could go wrong there.

But, now seeing your post... makes me wonder. I can also make the noise disappear if I put a tiny bit of pressure on the brakes while gliding over the bump. Same bump with no brake pressure will get the noise every time. Coasting or under acceleration makes no difference.

Any idea why that might be? Not talking enough brake pressure to really slow the car or compress the suspension... just enough to lightly drag the discs.

Pads and discs I ordered from rockauto - don't remember the brand, but it was under their selections for "premium"... i can find out if anyone thinks it matters.

 

The rattle is caused by one or more of three things assuming you didn't have the rattle before changing rotors and pads.

The anti rattle clips aren't doing their job.
More likely, the pads are true or the rotors aren't true.

If it were me and I've had this problem. I would pull the rotors and have them turned. It'll cost you $10 a wheel if you pull them yourself. Didn't solve the problem? Try a set of cheap organic pads. Didn't solve the problem? Replace the anti rattle springs.

Back in the day, rotors didn't always come turned properly. Even though they're sold that way now, they can still be off. Same can be said about pads.

Let us know what you do.

 

It could always be suspension bushes but the timing is suspicious as you note.

 

Come to think of it, not sure the new pads came with anti-rattle springs. I don't remember. Are those something i can just buy, or do I need to find a brand of pads that come with them. Disappointed because both were supposed to be on the higher-end. Bendix brake pads and Pagid rotors...

I'll see if i have time to check those things tomorrow, that would be great. Thanks Sean!

 

The anti rattle springs are mounted to the caliper and should have been reused. They last many years and rarely fail. I think you need to check the electronic parts catalogue. My Brembo's had them but i don't know what the base set up is and whether they even have springs. I suspect they do but don't know for certain.

 

Hello all,

Sorry for the delay in response. I am still dealing with similar lingering issues. While changing rotors, pads, springs and thoroughly cleaning and lubricating, problem is still there, however slight.

It is only apparent at speeds of 15 plus, particularly if I hit a cats eye in the center of the road, left front area. If I apply event the slightest pressure to the brakes, sound completely dissappears.No noticeable suspension or alignment issues.....drives great, but the nose is bothersome.

I know a trip to the dealer will get into a whirlwind of case.

Frustrated.

 

Suspension noises are a royal pain to isolate.

 

Yes - exactly this! I have a new data point -

Didn't have time to work on it today yet, but starting with the idea that dragging the brakes makes the problem go away I tried this:

After I started the engine, I sat there parked and pumped the brake pedal - as far to the floor and as much pressure as I could. After a few rounds of that, I proceeded as normal and for almost the whole trip home there were NO RATTLES. Eventually I started to be able to detect it again so at the stop signs I gave it a few more pumps then no noises all the way home.

So I think I am going to start there - the pads I ordered from RockAuto have a 1 year warranty, and I don't htink they came with anti-rattle springs - so I might order some new ones and get my money back on these.

But I'm comfortable its not the new Arnotts, will report back as soon as I am able!

adam

 

Since there are so many similar threads, I've also been trying to update them with my experiences down the same road - so forgive me if anyone has seen this, but for the OP if you haven't narrowed this down yet - here is something I found after I had replaced the sway bar bushings and end links -

Looks like I may have been right to suspect the brakes all along, particularly the lack of hardware - https://www.dropbox.com/s/vskku03h1v..._0030.MOV?dl=0

I plan to address that this week and will report back.

 

Yep the clips are clearly missing.