2004 XC70 Brake component in engine compartment

malcolmtent · Post by **malcolmtent** » 11 Oct 2019, 06:01

2004 XC70

I've been chasing a problem with my brake lights. At first my 2 lower brake lights wouldn't come on, but the top light did. But now the top light isn't coming on, either.

I've noticed a buzzing sound coming from the engine compartment while pressing the brake pedal and am wondering what component might be causing the sound. It's coming from lower in the engine compartment than the fusebox.

I'm pretty sure (but not entirely sure) that this is a new sound, and wondering if it's connected to the issue of my top brake light not working.

What would this component be?

Thanks.

Post by **oragex** » 11 Oct 2019, 06:36

The sound is the vacuum pump www.youtube.com/watch?v=PRbWD2OGytk
You can test it see if it works correctly www.youtube.com/watch?v=xwQG7xvXVp8
However the brake lights are not related to the pump.
The two lower lights may be related to the REM
https://www.volvoforums.org.uk/showthread.php?t=289930
viewtopic.php?f=9&t=89032&p=502180#p502180

malcolmtent · Post by **malcolmtent** » 11 Oct 2019, 13:19

thanks, I'll test the vacuum pump. Yes, I'm aware that the rear lights may be the REM. I've eliminated just about everything else at this point, but am curious to know why the top brake light has suddenly decided to not work. I was thinking that the new noise in the engine compartment might be the problem.