No brakes when first used (parking lot speeds) '04 V70 R

Post by **matthew1** » 23 Feb 2011, 14:45

My wife just called and reported the V70 R had no brakes when pulling out of a parking space. Second time in the last 3 months. She said both times there is typical pedal feel, just no stopping.

I had the brake fluid changed in the summer at a good shop. One pad might need changing, but it's just beginning its scratching/whining sounds.

Any ideas on what's going on?

Post by **jimmy57** » 23 Feb 2011, 14:55

Can you give more info?
My suspicion is the electric vacuum pump. Dual CVVT motors make almost no vacuum on a cold start (even worse at 5000 + feet) and have to have the electric vac pump functioning in the first couple of minutes or the pedal is as responsive as pressing on the floor. The first quick test of pump is key on, engine off brake pedal pumping to see if the pump comes on as vacuum drops.
The switch on the vacuum line is giving more problems these days but the system uses a relay too and we all know those can wear out or crack solder joints internally. The pumps can fail too and problems with check valves can occur.
Once the car runs for 2 minutes or less the cam timing and ignition timing is returned to normal control and the engine produces adequate vacuum for brake booster.

IS the problem a hard pedal or pedal dropping to floor or ?????

Post by **matthew1** » 23 Feb 2011, 16:03

Thanks Jimmy. She said the pedal feels normal. I'll be able to get my hands on the car in 2 days, I'm away right now.

Post by **JRL** » 23 Feb 2011, 16:11

Also what pads are on?
Ceramic pads feel like no pads until they hit a couple of times
Same with high performance metallic pads

Post by **jimmy57** » 23 Feb 2011, 16:41

I thought about the pad compound too but it should be a consistent problem every morning and evening when it's first driven if it's pad morning sickness.
The complaint most people state when the engine is cold and the vacuum pump isn't operating is "I push on the pedal and it just doesn't stop" . Volvo put several of those pumps on 99-01 S80 T6 models in high altitude areas and when the dual CVVT engines came out in 2002 they went widespread with them from factory.
The times I've jumped in one of the t6's with no vac pump and it was cold and I started engine and backed up, I was surprised by the lack of braking. When the high idle period is over it is normal again.

genuine · Post by **genuine** » 23 Feb 2011, 23:47

is this ure 2nd brake pad set?

if it is then please try to genuine ones again, word of mouth in parts dealers accounts for nothing as they dont know what they are talking about..
just because of their word of mouth u will ruin your cars quite quite expensive discs.

if it is not your 2nd set then probrably there is something wrong in your brake assembly. get a reliable mechanic with you and do some hard braking btw I recomended wagner brake pads so try to analyze what is the problem. maybe your brake line is clogged or maybe your master valve isnt proportioning properly. check all options before making an expensive upgrade to the jdm brake kit.

RaymanSean · Post by **RaymanSean** » 24 Feb 2011, 05:15

I would look for excessive brake dust from the parking brakes. You may have to remove the disk to see it.Here is why I think that it could be the parking brake: I had a BMW (I know not a Volvo but the brake systems are both made by ATE) that every now and then the parking brake shoes would remain engaged with the drum even though I had released the lever. It was never enough for me to feel in in the acceleration or in the gas mileage but enough to generate a crap ton of heat, enough to boil the brake fluid in the caliper. The symptoms I had was that after several hours on the highway I would have to pump the brakes once before getting stopping power (the pedal felt fine) and after long drives when I went to start the car again I would have to pump the brakes to get stopping power (again the pedal felt fine) while maneuvering in the parking lot. Since I had to pump the brakes to fix the problem I assumed it was vapor in the lines so I bled the brakes and sure enough there was vapor in one of brakes. When the problem presented again I bled the same brake again and there was vapour again. Believing that vapor does not just enter the system through the brake caliper I assumed the caliper was sticking so I pulled the caliper all seemed good and then I pulled the disk and dumped a small handful of dust from the parking brake drum. I forget what I did to fix the parking brake but I think all it needed was a little adjustment or a new spring.

Post by **matthew1** » 24 Feb 2011, 10:00

Jimmy, I think you got it. After my posts yesterday I got to speak with my wife again on the phone about it, and when I asked if it happens when she's in a hurry she said yes... the correlating piece is that both times she turned the car on and backed up, no waiting.

About the pedal, I don't know that what she said about the pedal feel was accurate. She was very flustered and when your adrenaline is going in panic situation, memory of the event suffers. And she was panicked -- she tapped the car behind her yesterday. No damage to either vehicle, luckily.

I told her to give the car 30-60 seconds of idle before D or R.

Genuine: I'm not sure which brake pad set this is. We bought the car with 89k, so it could be 3x on front, 2x on rear, at the very least. I have the maint. records... here's my big reason to go over them and make notes.

Rayman: Nope, not the parking brake sticking. She doesn't use it

despite my pleas. She's from Iowa. For those who haven't seen Iowa, here's a representation of the landscape -> __________________________.

Thanks all, I'll report back when I see the car.

Post by **jimmy57** » 24 Feb 2011, 10:12

LOL about the topographical map of Iowa!!!!
I am OCD about parking brake use and my spousal unit has hurled things at me a few times over my dogged insistence on HARD parking brake application before the lever goes to P.
I have seen the size of the parts in transmission used for holding car still and they are not sized or shaped to give me easy rest.
Then you get around the use of plastic parts on end of the shifter cable and their ability to withstand the MUCH higher stress when gear lever has to get trans out of P on a hill........

RaymanSean · Post by **RaymanSean** » 24 Feb 2011, 20:19

JImmy, I have only seen the insides of ZF transmissions for traditionally mounted engines and I was pretty impressed with their setup. Hopefully, I will not have to see the inside of a AW transmission anytime soon.

Mathew, when I travel to the colder parts of the country during winter and there is precip on the ground I try not to use the parking brake if I can help it (my daily driver has a manual tranny, my wife drives the volvo). I have had my pads freeze to the drum before. So your wife may have a slight point, provided she does not park on a hill which may be hard to do in CO. In regards to the topology of Iowa I think you need to extend those lines a little further. I am looking forward to learning what the cause was. Perhaps you may suggest to your wife to listen to some calming music for a few mins before putting the car in drive when she is flustered.