2006 V70 brake Vacuum pump/switch 31317445 31265825 Topic is solved

Perry V. · Post by **Perry V.** » 02 Jul 2016, 17:43

I followed your detailed replacement plan for the vacuum pump. As far as I can tell everything went as expected except that the pump still comes on a lot. Every time I step on the brake pedal it comes on and when I turn off the engine as well. The wife thinks that it used to never make the pumping/whining noise but it would have to come on to assist the braking when needed. Would it run too much if there were a vacuum leak? It is a 2002 S 80 T-6 but I don't drive the car very often so just not sure about the cycling of the pump and its frequency/need of operation. What are you thoughts.

Perry V.

Post by **abscate** » 03 Jul 2016, 06:20

Definitely a vacuum leak. Primary suspect the sensor valve in front of the air cleaner box, known to fail.

TonyC52 · Post by **TonyC52** » 24 May 2018, 08:41

Hi, this is a great article but I have a problem at Step 2. I have checked the voltage and it returns zero. I went to fuse 33 and it seemed fine. Took to my local Volvo dealer and they confirmed fuse is fine. Just in case I changed fuse but still get no voltage. User manual confirms fuse 33 is for Vacumn pump only. Does this mean there is a fault in the wiring assembly or the switch connector?

UK 2005 S60 2.0T SE

Many thanks.

Post by **oragex** » 24 May 2018, 09:12

This pumps goes bad when there is a vacuum leak at the brake booster. As the booster vacuum drops below a certain level, the pump kicks in to bring the vacuum back to the level. However, because of the leak, the pump runs way too much and wears out (the brushed wear). Usually, the pump will run after shutting the engine off (will run intermittently for 5-10 times), or when the car is started in the morning, or when the car has just been parked and the brake pedal is depressed. Sometimes the pump can be heard running even while driving the car.

Check first the pump switch, the top plastic can break loose. Make sure the connector is fully engaged as well.

Before suspecting the diaphragm inside the booster, there are two or three places where the leak this happens: under the grey bellow inside the car, at the vacuum hose from the pump where it gets into the booster (a rubber seal), or at the diaphragm position switch seal (the sensor right near the master cylinder).

But the most common is the seal under the grey below, it gets dry then gets torn. It better to lubricate this seal before this happens with the Volvo grease #1161688 only.

The seal https://www.ebay.ie/itm/BRAKE-BOOSTER-S ... Sw14xWIM9o

Here's how to lubricate it (apply the grease on the white cylinder near the seal)

TonyC52 · Post by **TonyC52** » 30 May 2018, 07:55

TonyC52 wrote: ↑24 May 2018, 08:41 Hi, this is a great article but I have a problem at Step 2. I have checked the voltage and it returns zero. I went to fuse 33 and it seemed fine. Took to my local Volvo dealer and they confirmed fuse is fine. Just in case I changed fuse but still get no voltage. User manual confirms fuse 33 is for Vacumn pump only. Does this mean there is a fault in the wiring assembly or the switch connector?

UK 2005 S60 2.0T SE

Many thanks.

Any ideas anyone?

Post by **oragex** » 15 Jul 2018, 04:25

An updated video

franbee · Post by **franbee** » 09 Nov 2018, 12:29

Does a 2004 XC70 have these assist parts because that is exactly the issue I am having. Thanks

Post by **June** » 09 Nov 2018, 14:29

537playing wrote: ↑09 Nov 2013, 15:07 Nope. Not on the S80

My 04 S80 T6 has the same switch as in the OP. What is it there for in the S80? Just curious, my car had the switch go bad a few years back. June

XC70Rider · Post by **XC70Rider** » 09 Nov 2018, 18:17

Correct me if wrong but I've read that only Turbo engines have the brake vacuum pump?

This thread helped me last May. Before purchasing I could see both rear calipers were seized. Had the dealer drop the price down $500. First thing I did when I got her home was install 4 new ATE calipers, 4 new brake hoses, 8 new ceramic pads, 4 new brembo rotors, new rear parking brake shoes, and flushed out old blue brake fluid with SL6. After this the brakes were still soft during startup?

After reading this thread I checked the vacuum pump and it wouldn't turn on. Fuse was fine. Tested the check valve switch and found it was always open. I tackled this within 1 week so I had the used dealer pay for a new pump and switch which I installed within an hour.

Post by **oragex** » 09 Nov 2018, 18:27

Not about being turbo or not, more about the year the car was made.

2006 V70 brake Vacuum pump/switch 31317445 31265825 Topic is solved

Re: No Brakes when cold - Vacuum pump/switch replacement w pics