XC90 Vacuum Pump

luckyfanfan · Post by **luckyfanfan** » 19 May 2011, 19:58

trstjohn wrote:where did you get the valve from?

i got it from dealer here in Toronto, however, you can buy online as well, i think it is like $10 cheaper...i didn't want to burn out the vacuum pump, so i got it from the dealer asap...cost me $84 tax included....

luckyfanfan · Post by **luckyfanfan** » 19 May 2011, 20:52

just some pictures and a quick write up...

trstjohn · Post by **trstjohn** » 20 May 2011, 07:12

fantastic directions!

Maybe my ignorance here, but is there a difference between the brake booster and the check valve?

Since I have a 2003 XC90, should I be getting the following part?

http://www.volvopartswebstore.com/produ ... 45383.html

Post by **jimmy57** » 20 May 2011, 09:08

Yes, the booster is mounted to the firewall and it has a check valve on its hose connection. The hard plastic piping that has the electrical switch for vaccum pump also has check valve in it.

bmoore · Post by **bmoore** » 23 May 2011, 10:13

luckyfanfan wrote:just some pictures and a quick write up...

Nice write-up. I had this problem with my XC90 and had it fixed (finally) under CPO.

Shortly after I bought the car a couple years ago, I noticed that there was very little braking power as soon as I started the car after it had sat for a while. It was annoying. However, I also noticed that when I had the cruise control set at ~60mph for 5-20 minutes, when I'd go to brake, the pedal would be rock-hard. Now I know enough to just push harder, recognizing that it was just a loss of vacuum assist, but it was still unnerving for me. It could be downright dangerous with someone less mechanically knowledgeable.

First time I took it in to the dealer, they replaced the brake vacuum pump. Within a day, the pump was screaming and continually on. I called the dealer, told them that the pump was extremely hot and they told me "well, things under the hood do get hot." Gee, thanks. I just left the car on for about 20 minutes and the problem took care of itself... the pump burned out. As soon as it did, I took a temperature reading of the pump -- over 340*F. Yeah, things under the hood get hot, but not like that.

The second time the dealer took a shot at it, they replaced the pump (again), a hose that had been burned from the first replacement burning out, and the switch. That seems to have solved the problem.

This seems to be a common enough problem that there should be a TSB or recall, since it is potentially very dangerous.

trstjohn · Post by **trstjohn** » 17 Apr 2013, 15:37

As luck with not have it, I have to replace the vacuum pump on my 2007 XC90. Are there any differences in swapping this out as compared to earlier versions? Any tips?

crazyaboutvolvoxc90 · Post by **crazyaboutvolvoxc90** » 21 Oct 2013, 16:31

I have a 08 XC90 3.2L FWD
After scheduled maintenance at the dealership it was discovered that my vacuum pump leaking.
The leakage is the engine oil that somehow getting out of (vacuum pump?) or the seal (O-ring)
While I was shopping for the best price on parts and labor I spoke to one tech at the dealership and he told me that the most likely problem isn't the pump but O-ring ($336.00 vs. $8.00!!!). I am thinking to give it a shot but I'd like to get your opinion if somebody on this forum resolved this issue by replacing O-Ring and may be willing to share with instructions .

crazyaboutvolvoxc90 · Post by **crazyaboutvolvoxc90** » 21 Oct 2013, 16:38

After schedule oil change at the dealership it has being discovered that my 08 XC90 3.2L 6 cyl FWD has a leaking vacuum pump. Apparently, it's bleeding engine oil and I noticed spots in garage.
After shopping for parts and labor I came across on tech at the Volvo dealership and he told me that issue most likely O-ring and not the vacuum pump. ($336.00 vs. $8.00!!!). I am thinking to give it a try.
However, I'd like to know if anybody on the forum has fixed the oil leakage by replacing O-ring only.
The current problem doesn't affect braking at all.

marmotteNZ · Post by **marmotteNZ** » 18 Aug 2014, 18:09

Hi all.

I take the liberty to hack this thread as I have similar issues or concerns with my 04 XC90 2.5t.

The vaccum pump runs for a few seconds as soon as I brake, lightly or firmly...whatever.
More funnily, while parked with parking brake on, if I press the brake pedal and let it pressed-down, of course the vaccum pump runs for a few seconds then stops; but then, when I let the pedal go, it runs for a few seconds as well.
A couple of times I have heard it running continuously before realy knowing what it was. When that had happened, I had parked and stopped the engine then started again which had solved the issue.

I guess the switch needs replacing but is there soemthing else going on ? (leaky vaccum somewhere? If that is the case, woudl I have to replace just all hoses with the pump, or also somethign else more expensive?)

I removed the hose from the pump; when running it "sucks up" as expected but quite lightly (i.e. it pulls lightly on my finger...not painfully). Is it what it is supposed to do?

Thanks a lot for any advice

Post by **jimmy57** » 18 Aug 2014, 22:08

The times your pump is running are when the vacuum brake booster needs vacuum.
The problem is that the electric pump shouldn't have to supply the vacuum unless engine is started in cooler temps when engine is also cold. I suspect there may be a blockage or stuck check valve in the line from engine to brake booster. That line also has the electric vacuum pump attached to it.

XC90 Vacuum Pump

Re: XC90 Vacuum Pump