Brakes Not Working When Turning On My S60 2007

[ddevinatea]

Hi there!

I have a 2007 Volvo S60 2.0T and I have the following problem;

When I turn it on and the car has been turned off for a couple of hours or early in the morning the brakes do not work properly, I mean you can break but you have to apply a lot of force. After the car heats up, for around a minute or two, the brakes work properly again. This is very dangerous and annoying since I almost crashed in my garage. I am also very concerned about the brakes failing when using the car at high speeds.

Anyone have an idea of what could it be?

Thanks in advance,

David

[ddevinatea]

Pretty common problem unfortunately, the seal on the brake booster is probably compromised, and the brake vacuum pump has worn out. Regardless, the vacuum pump is probably not coming on, perhaps because it isworn out. I'll find you a link.

Here is a thread with full discussion of possibilities from when I had this problem on my car, it has lots of links too. You will also want to check the switch: viewtopic.php?f=9&t=85448

[ddevinatea]

Thank you so much! I will check!

[ddevinatea]

That is a little strange it works once is warmed up. How cold is the weather there? I assume the car was recently purchased?

My first thoughts went with a frozen brake fluid if weather is sub zero, from either water in the fluid or wrong fluid altogether. I've had this experience on two other cars, with contaminated brake fluid, brake pedal getting very stiff in very cold weather until the car would warm up.

But as mentioned above, it's a classic description of a failed brake booster or seal, I'm just surprised it comes back to life by itself. Maybe also look at the pump switch, see how it is here www.youtube.com/watch?v=PRbWD2OGytk

[jimmy57]

VVT setting and timing retard for initial run period from cold for faster warm up diminish vacuum level. This is the 95% of the reason for the pump. Once engine has run a short time, time dependent on start temp, the cam phasing and ignition timing are back to normal control and intake vacuum is 15 inches or much more. The initial settings require a lot more throttle opening to keep idling speed and the idle speed is increased for that initial period. Higher throttle kills the vacuum. The s40/v40 4 cylinder models needed the vacuum pump once warmed up. Low compression ratio together with auto trans, engine driven power steering pump, and air con compressor was enough load that so that this model needed the aux vacuum pump with normal operating temp engine. Condition is worse as altitude increases too.

[ddevinatea]

That is a little strange it works once is warmed up. ...

I think not unusual, what OP describes was exactly the symptoms when the pump was bad on our S60. Probably not very unusual it actually makes sense. See jimmy57's post for much more insight but basically once the engine warms up and develops vacuum the pump is not needed.

[ddevinatea]

That is a little strange it works once is warmed up. How cold is the weather there? I assume the car was recently purchased?

My first thoughts went with a frozen brake fluid if weather is sub zero, from either water in the fluid or wrong fluid altogether. I've had this experience on two other cars, with contaminated brake fluid, brake pedal getting very stiff in very cold weather until the car would warm up.

But as mentioned above, it's a classic description of a failed brake booster or seal, I'm just surprised it comes back to life by itself. Maybe also look at the pump switch, see how it is here www.youtube.com/watch?v=PRbWD2OGytk

Hi! I live in Lima, Peru. We are currently in the summer with temperatures within 25 and 30 degrees Celcius. I purchased this car in January this year and didnt noticed the problem. It was a bargain though US$ 5000 for a car that sold for much more US$40,000 when new

[ddevinatea]

If you turn ignition on but do not start engine you should be able to push and release brake pedal 2-4 times and then you should hear the vacuum pump run for 3-10 seconds and then go off. Pushing brake twice should make the pump run. The switch is behind left headlight with two wires in a brown connector plugged onto a round switched at a junction of three rubber hoses. The pump is below the air filter housing and is silver and roughly the size of a soup can. One of those from the switch plumbing will lead to the pump.

[abscate]

Altitude might be contributory here. I've spent time in Cusco, most of which in dipilitating altitude sickness.

[ddevinatea]

Altitude might be contributory here. I've spent time in Cusco, most of which in dipilitating altitude sickness.

Cusco is in high altitude around 3000 meters above sea level. I am in Lima that is at sea level