Hcloud13

Hi everyone. I actually have a 04 Cadillac XLR. but the brake system is exactly the same set up, and not many people turn there own wrench over at the XLR forums lol. So I thought maybe someone over here might be able to help.

I'm totally stumped.

So about a week ago my front LH/ Drivers side caliper started making a horrible grinding/clicking sound whenever I hit my .. Doesn't matter how fast or slow I'm going, or forward or reverse.
Had someone move the car so I could take a look and every time the is applied the entire caliper moves up about a quarter inch! Same but down in reverse .

I jacked up the XLR, Removed the caliper and rotor for inspection and found nothing visually wrong, then with the caliper off I noticed one of the Caliper pistons is not even with the other one, So I compressed the pistons and had someone hit the brakes, the lower piston was barely moving and not lining up with the other one.

So I thought that was the problem and ordered a brand new Caliper. Installed it, bled the brakes, ect.. Took it for a test drive and it is still doing the same exact thing! What the hell!? Anyone ever have this problem? At this point I have no idea what it could be!

My only other guess it it's not getting enough pressure to that caliper to fully compress?

EVRose

Is the caliper bracket moving with it? If so you may have a bolt missing on the bracket.

Hcloud13

The caliper bracket it's self is not moving, only the caliper. When I was checking everything out I checked all the bolts and everything was tight.

Landru

On a chance you've not visited this place: http://www.cadillacforums.com/

While caliper/brakes may be same as C6, this problem might be specific to XLR & Cads employing similar set-up. If so it'll stump everyone here, too. Salient point being entire brake assembly, on any vehicle, should never move a'tall.
Obviously, something's different here from XLR to C6.

IF you haven't already, try link, lots of informed Cad enthusiasts.
Been much help to me over the years for my CTS4 ID'g an issue before taking it to our wrench.

Hcloud13

Yeah, I checked there, but the XLR board is not very active. Last post was early November. I could take it to a mechanic.. but that just burns my britches as I usually do my own work lol. I can rebuild an engine, but I can't figure this out haha

Landru

When this kind of crap happens, it's helped I set whatever it is aside & think about what I'm missing. When pissed I get tunnel vision, bad.

Whatever's happening here is probably in plain sight, problem is not knowing what 'right' looks like.
Given you sound like a seasoned wrench, you're light years ahead of any insight I have.

Try posting this in C6 Tech, Hc.
Only challenge is getting issue in front of those who'd have some valid idea(s). Better odds in C6 Tech.

Hcloud13

Will do! Thanks. Sorry.. I thought I was posting in the right area. I won't lie, I'm terrible with forums lol.

jdvann

Did the caliper come with new guide pins? I would think these need refreshed as well.https://www.partsgeek.com/xgxl54x-ch...ad=11620898036

Of course these are for an 06 Corvette maybe not your fitment.

CMY SIX

did you look at the other side and compare?

SteveDoten

The bracket and/or guide pins are worn or your missing the pad slides.

Are the pins freshly greased?

I've seen this on 80k plus cars.

FatsWaller

The caliper is bolted (two bolts, one top and one bottom) to the steering knuckle. So, all of the rotational braking force gets transferred to the knuckle. Since the knuckle is held in place top and bottom between the A-arms by the upper and lower ball joints, it can't rotate. I think the brake caliper on those cars sits at the rear of the rotor, not at the front, so braking forward motion would tend to force the knuckle upwards (since it can't rotate), and downwards when braking reverse motion. If the caliper was moving up and down, to me, the only way that could happen would be if the knuckle was also moving up and down. I suppose this could happen if the ball joints were worn, or are loose, allowing the knuckle to move up and down between the A-arms. If this is the case, you really don't want the knuckle to come completely loose from between the A-arms - you can imaging the result, especially at speed.

mikeCsix

Like CMY mentioned, I’d compare what I was seeing on the drivers side to the passengers side. I would the put the front end on jack stands, Pull the wheels, rotate the steering wheel untilI could see the backside of the calipers, then using a long lever arm, attempt to move the caliper to see what else is moving. There has to be something obvious in the mounting system.

Hcloud13

Thanks everyone for all the help and advice on where to look/check.
New slide/guide pins and rubber pads came with the new caliper. I'll jack up the car tomorrow as I have the day off and jack up the entire front and compare both sides.
I'll also take pictures and videos so you guys can look with me . Maybe you will see something i'm missing

ruxvette

As Fats said...look for play in the ball joints, etc.

SteveDoten

Then I'd swap out a new bracket, about 45-50 each new GM.

Hcloud13

Well damn lol. I was going to take a video and it stopped doing it -_- . I was trying to make it do it and nothing. I have to take a quick trip up to my mom's today, So I'll see how it goes.
I was all up in there and couldn't find anything visually wrong. I know problems don't just "go" away. So I'll see what happens today on this trip.

buckmeister2

Good luck on your trip. Not sure I would go anywhere with a brake caliper that is moving when brakes applied.

Buy a Corvette...nothing ever goes wrong, and we have a truly superior forum.....

Hcloud13

Started doing it again. Just went by Ed Morris Cadillac and placed an order for a new Caliper Bracket. only 50$. Hope that fixes it. All together that will be a new caliper, Pads,Clips,Slider Pins & soon the bracket.

Hcloud13

The XLR is kinda a Corvettte... kinda lol. Just wish I had your engine. It's like a fancy dressed vette without all the up n go.

Hcloud13

FOUND THE PROBLEM!! It's the damn Hub assembly! never thought to grab it and move it around, but there is some minor play in it..and it's enough to throw everything else out of wack.