2004 Volvo S90 • 130,000 miles

I have been told that the Part Number is 30793669 and there are two Break Pressure Sensors on the breaking system. They should be replaced at the same time. I can't find them on the internet. How do I purchases used or re-build?
December 6, 2011.

According to my info, both are on the master cylinder. I would recommend a new part rather than a used since it is a safety related component.

The main one that usueally fails is the one on the brake booster. It is held down by a snap ring. See picture please. Before you remove the sensor pump the pedal a few times with the key out of the ignition. That way you remove most of the vacuum or you can unplug the vacuum hose. If you dont then when you remove the sensor the vacuum sucks in the oring. If it does it is no big deal but better if it doesnt LOL. What I do is using a pocket screw driver I push agains one of the "C" clips corner to make it bend out and then I oull the sensor out. Lube the new oring with a little bit of grease or some vaseling and to install pry on that clip the same and insert the new sensor. The sensor goes in one way so pay attention to how it came out and where the guide tab is out. When you release the clip that will lock the sensor in position. Doing it like this you do not need to install the new clip since that is the hardest part of the job. Again this sensor is if you have a a reduce engine performance message on with a fault code for a faulty sensor or an anti skid light with a fault code for a faulty sensor.
Good luck to and keep us posted please.

Dec 7, 2011.