Brakes: Warped discs ?

[steve70v]

Hi everyone.
I am new to this forum and a new Volvo owner
I have a mint V70 Auto D5 2005 model which runs like a dream, no real issues with it apart from parking sensors not working.

I was driving down a long incline at the weekend, had to keep my foot lightly on the brakes for quite a while, no problem there at all, but later when I came off the motorway and braked a bit harder than normal, I felt what appeared to be a sign that the brake discs had become warped. it felt like the brakes were kind of grabbing.

Strange thing is, later when I applied the brakes the slow down was smooth and no noticeable sign of the previous issue which lead me to think it might have something to do with the Auto gear box.

I have noticed occasionally when starting from cold, the first time I use the brakes, I feel this grabbing issue, but it disappears by the next time I use the brakes, so again, I am wondering if it an issue with the auto gear box

The car has done 126,000 miles, just recently serviced at a Volvo specialist who told me the disks and pads were ok, I checked the auto gear box oil both when hot and cold and the level is spot on, the color of the oil is a reddish brown as well.

Anyone know what the problem might be ?

Thanks in advance.

[Spike56]

Perhaps the ABS kicking in??

[360beast]

The gearbox oil needs changing if it has a brown tinge, should be bright red.

[Sphinx2000]

Sounds to me possibly caliper issue. Any garage can check the disks are warped by using a dial gauge. Could be the caliper pin is sticking.

Other than that, check the pads or get the brake fluid checked and changed.

I don't think It's a gearbox issue, from what you have said so far.

[P156KWJ]

When I had warped discs on the front of my S40, it was a distinctive rumble and steering wheel shake, but also as you slowed down below about 10mph you could feel that if you held the brake lightly and steady, with the rotation of the wheels, sometimes it would grab a bit and sometimes roll free, in a pattern.

Sticky caliper could be the case if it feels like an intermittent fault, might not be releasing all the way.

[green van man]

What pads are in it?
Long use of the brakes however lightly will heat them considerably, this heat can cause varnish to form on the pads and this affects their coefficient of friction, hence the grabbing. Once cooled to normal tempretuses the brakes worked as expected.

If the problem persists I would look at a pad change, otherwise don't worry about it.
If the pads are new this could just be them bedding in. Back when I biult rally cars as a hobby new pads were bedded in by bolloking the brakes untill they faded, then drive gently untill they cooled, there after they were wonderful and worked in all conditions, even with the disks glowing orange.

Bare in mind it's almost 2 ton of car, draging the brakes to control speed will generate a lot of heat, if this was the first time the pads have got this hot they are now cured and should give no problem provided they are decent quality.

Paul.

[Clan]

Originally Posted by steve70v

Hi everyone.
I am new to this forum and a new Volvo owner
I have a mint V70 Auto D5 2005 model which runs like a dream, no real issues with it apart from parking sensors not working.

I was driving down a long incline at the weekend, had to keep my foot lightly on the brakes for quite a while, no problem there at all, but later when I came off the motorway and braked a bit harder than normal, I felt what appeared to be a sign that the brake discs had become warped. it felt like the brakes were kind of grabbing.

Strange thing is, later when I applied the brakes the slow down was smooth and no noticeable sign of the previous issue which lead me to think it might have something to do with the Auto gear box.

I have noticed occasionally when starting from cold, the first time I use the brakes, I feel this grabbing issue, but it disappears by the next time I use the brakes, so again, I am wondering if it an issue with the auto gear box

The car has done 126,000 miles, just recently serviced at a Volvo specialist who told me the disks and pads were ok, I checked the auto gear box oil both when hot and cold and the level is spot on, the color of the oil is a reddish brown as well.

Anyone know what the problem might be ?

Thanks in advance.

Probably one of the brake pads seized in it's holder ....

[capt jack]

I'd be tempted to take the pads out, give everything a good clean with brake cleaner, re-grease the pad backs and pins with brake grease, and then put it all back together. Cheap and easy and can't do any harm.

Jack

[steve70v]

Originally Posted by capt jack

I'd be tempted to take the pads out, give everything a good clean with brake cleaner, re-grease the pad backs and pins with brake grease, and then put it all back together. Cheap and easy and can't do any harm.

Jack

Thanks everyone for the replies.Had the discs checked for warping by an experienced ex Volvo mechanic employee of Doves in Preston. No issues on the discs but one of the calipers was sticking, it was removed and greased / cleaned and is ok now.