98 V70 Brake squeaks - don't understand the cause

Post by **98v70dad** » 09 Oct 2016, 15:35

I took the 98 V70 camping up in the north georgia mountains this weekend and suddenly the brakes have started squealing/squeaking. I had to drive 13 miles on a US Forest Service road which is essentially a very curvy improved dirt road. They are extremely dusty even though the top course of the road is usually small gravel. All of my brake pads are new. The front pads are volvo pads have only been on the car about 6 months. The back pads are Textar and are about 18 months old. I don't put on enough miles on in a year to have worn out any of the pads this quickly. I probably need new rotors all around because they are all getting a lip of about 2 mm. All of the squealing seems to be coming from the front.

I went backpacking yesterday and was standing on top of Springer mountain, the Southern end of the Appalachian Trail, this morning. Although my knees hurt and my thighs are burning, I had a good time. Unfortunately the Volvo didn't.

So, does anyone have any idea what might cause the squealing.and what might need attention?
.

JeffHicks · Post by **JeffHicks** » 09 Oct 2016, 17:29

It's just about impossible to diagnose without looking at them.

It is possible that you have a caliper not releasing as it should. Or the pins could be dirty or rusty. It's possible (though not likely) that you have a small stone or something up in there. It is also possible that a fleck of the "metalic" part of the pad is squealing. It's a guessing game.

Does it squeal only when you're applying the brakes, or does it squeal all the time?

Post by **98v70dad** » 09 Oct 2016, 18:06

JeffHicks wrote:It's just about impossible to diagnose without looking at them.

It is possible that you have a caliper not releasing as it should. Or the pins could be dirty or rusty. It's possible (though not likely) that you have a small stone or something up in there. It is also possible that a fleck of the "metalic" part of the pad is squealing. It's a guessing game.

Does it squeal only when you're applying the brakes, or does it squeal all the time?

The pins looked ok when I put the front pads on 6 months ago.

Squeals when I first apply the brakes and stops as pressure is applied. There is a lot of brake use on a forest service road because of frequent hairpin turns and the roads are nearly not wide enough for two cars to pass so you have to slow down. Max speed is about 20 mph. I noticed a much heavier film of black dust on the front rims than usual.

I will take a look tomorrow.

beigg · Post by **beigg** » 09 Oct 2016, 18:52

bum wheel bearing?

Post by **erikv11** » 09 Oct 2016, 22:42

98v70dad wrote:... I went backpacking yesterday and was standing on top of Springer mountain, the Southern end of the Appalachian Trail, this morning. Although my knees hurt and my thighs are burning, I had a good time. ....

Not much help but: I am green with envy!

I wonder if it is the dust. Maybe they will quiet down this week, please keep us posted on that if nothing else.

Cees Klumper · Post by **Cees Klumper** » 10 Oct 2016, 00:16

My guess it it's a small stone caught somewhere, either between the disk and dust shield or in a brake pad or somewhere's else causing this.

Post by **misha** » 10 Oct 2016, 04:58

It could be that you overheated rotors with calipers which don't release properly because of accumulated dust and dirt...or like others allready said that something stuck between rotor and pad.

Or....you overheated rotors and that made a burnt layer on their surface.That burnt layer can cause the brakes to squeel like train on light braking.

When you look at rotors...are they shiny or they have some violet/blueish colour on braking surface?

Post by **rspi** » 10 Oct 2016, 07:57

Does the rear pads have the squeal shims installed?

Post by **misha** » 10 Oct 2016, 08:59

rspi wrote:Does the rear pads have the squeal shims installed?

98v70dad wrote:...All of the squealing seems to be coming from the front...

Post by **theWIFES_S70** » 10 Oct 2016, 10:50

I second the stuck caliper issue... Ever since I had two stuck calipers last winter. They wouldn't always stick! Now, after longish drives, I always put my hand on the rim gently and feel for heat, to make my sure my brakes aren't sticking. I'm convinced stuck brake calipers are what lead to premature bearing failure in these P80s.