Loose Caliper / Caliper Play

**anyadang** · 10-11-2011, 06:06 PM

I just bought my 2003 XC70 on Saturday from a public auto auction. 156,000. I think I got a decent deal at $5,495- despite these issues...

Day 1 – check engine light – I checked the code, and it was vacuum related. I found a disconnected sensor under the hood (behind the driver-side headlight on a vacuum hose) I hooked that up, cleared the code and no CEL for ~150miles

Day 3 – rattle from front end – Researched online and determined this was probably the sway bar links, so I ordered some on ebay (BUT! I was wrong – read on!)

Day 4 – Brakes star grinding, or so I think – looking through wheel spokes, rotors look brand new – plenty of width on the pads.. So, I jack up the car for the first time. I reach in to check the sway links, and they feel really solid … hmmmm.. I do find something loose though – front passenger brake caliper!!!

The lower ?? slide bolt ?? was not screwed in at all on that side. After pulling the wheel, I could rotate the caliper on the upper slide bolt… yikes! I pulled both bolts out and they looked the same. I put them back in ALL THE WAY, and the caliper felt secure.

I GUESS THIS IS MY QUESTION: I can rock the caliper a little bit – just enough to notice – if I grasp it. Do I just need to bleed the brakes?

I put the wheel back on and no more rattle – excellent! What’s even more excellent is that the caliper didn’t come off on the highway and lock up my wheel at 80mph!

I swear I still hear a little grind as I come to a stop, but I'm listening very carefully after the above mentioned.

So obviously the last mechanic or owner that worked on the car screwed up big-time. (I forgot to put a nut on a ball-joint once, so I won't rag on them too much) Is it just me, or are these slide bolts pathetic?; there are 4 or 5 rows of threads, and they’re pretty course. Any other brakes I’ve worked on have 10 or more threads and they’re usually pretty tight. The bolt-and-slide-in-one design seems the most secure.

But aside from it possibly nearly killing me on the highway there, I really like the car. Very comfortable seats. I would have died comfortably.

**sjonnie** · 10-11-2011, 06:13 PM

Sounds like your MAF was disconnected, expect problems there in the future. Maybe give it a clean now? Check the cleanliness of the air filter.

Get new caliper bolts and consider a dollop of locktite to keep them in.

**anyadang** · 10-11-2011, 06:21 PM

Actually, I looked it up and it's the "vacuum booster" sensor...

I'll check on the caliper bolts - thanks. I'm glad to see such reasonable prices on parts - - - my first Volvo.

Originally Posted by sjonnie

Sounds like your MAF was disconnected, expect problems there in the future. Maybe give it a clean now? Check the cleanliness of the air filter.

Get new caliper bolts and consider a dollop of locktite to keep them in.

**sjonnie** · 10-11-2011, 06:35 PM

The manifold/boost pressure sensor? Odd that would be unplugged, but it would give you a code for sure.

**Ocean Racer** · 10-11-2011, 07:47 PM

Have a read of the thread "Changing XC brakes to R Brembos"
Those 2x 15mm nuts should be in TIGHT !

**Xilikon** · 10-12-2011, 06:28 AM

And do you see a caliper spring installed ?

**anyadang** · 10-12-2011, 07:03 PM

Originally Posted by Xilikon

And do you see a caliper spring installed ?

I'll have to check again on that to be sure - thanks.

**anyadang** · 10-12-2011, 07:05 PM

Originally Posted by Ocean Racer

Have a read of the thread "Changing XC brakes to R Brembos"
Those 2x 15mm nuts should be in TIGHT !

Wow - that's a cool thread / mod. I don't need brakes like that for my commute though

I think the 15mm nuts you mention are on the caliper bracket. The one that was loose was the lower slide fastener - it take an allen wrench, and has a plastic cap.

**anyadang** · 10-14-2011, 09:23 AM

Is the drum inside the front rotor part of the emergency brake system?
I'm thinking that might be the grinding I somtimes hear, because the rotor surface looks great and the pads are plenty thick.