S/V40 [solved] 2002 Auxiliary Electric Vacuum Pump 'Whirring'.

MaxMax (@Max) Central Coast NSW
edited July 12 in Troubleshooting
The aforementioned auxiliary pump is noisy.
I can get one in a few weeks from China for abart $100. But it'll take a few weeks.
Any hints 'n tips re getting a rebuilt one in Oz? I feel if I get one the mechanic around the corner could install it pretty easy. I am too old too see clearly and do things I used to do.
(It's happened 'Just in Time' for my Sweety's car to be off the road getting and ign barrel issue fixed up and she'd borrowed the S40).
The car now has 308K Kms on syq2xkmsf6cw.jpg
the clock.


  • edited June 10
    They're noisy when they operate.
    If you turn the ignition on it should run for about 30 seconds and switch off until you press the brake pedal, which will switch it on again.
    If it's just running all the time you have a problem with the check valve or a leaking hose.
    I would not replace the pump just because its noisy they all sound like a swarm of bees.
  • MaxMax (@Max) Central Coast NSW
    edited June 25
    Thanks Timbo,

    As attached - a probable leak. What solution do you think?
    New hose and attachments? Or perhaps an 'O' ring?

  • MaxMax (@Max) Central Coast NSW
    edited June 11
    When I turn on the 'ign' the pump loudly whirrs for ~ five seconds and goes quiet.
    When I start the engine it starts whirring loudly and doesn't stop.
    Now, I figger cars use the vacuum from the inlet manifold to boost the brakes. My car is a Turbo and this auxilliary vac pump creates this vacuum. I assume there is a sensor to detect the loss of vacuum.
    The hose that enters the manifold doesn't seem to have any sealing qualities - it just 'sits there in a hole' with hard mating surfaces.
    So, now the pump goes all the time, even at road speeds, it logically seems as if
    a) There's a leak in the plumbing or,
    b) The sensor's a bit dickie or, ...
    My front yard is my workshop.

  • MaxMax (@Max) Central Coast NSW
    Further thoughts - if that pipe doesn't fit neat into my inlet manifold, it's be playing havoc with my mixtures!
    Any thoughts on this?
    I am not as knowledgeable with motor car engines as motor bikes.
  • Are you sure that the whirring noise is the vacuum pump? It sounds more like the fuel pump.The vacuum line that is loose in the manifold is nothing to worry about ,the minute air that is sucked in is not going to affect the mixtures
  • That hose is a push to connect fitting but it looks like it may have failed if you can simply remove it from the manifold. You usually need to push it into the manifold slightly, and push the outer ring (where your yellow arrow is) to release it.

    Its enough of a leak to throw your short and long term fuel trims out.

    Can you take some more photos of the hose routing as there were a few different setups on the s40 and i can point out the vacuum sensor.
  • MaxMax (@Max) Central Coast NSW
    edited June 25
    Thanks Crackers,
    It's definitely the device indicated - I can feel it as well.
    The hose going into the manifold just lifts out. All the hoses look in real good condition. I feel the only flaw in the system is the manifold .
    Here're some more snaps ...

  • carnut222Greg S (@carnut222) Daylesford VIC
    It definitely should not run very often...it’s really more of a back-up pump on the turbos since they don’t have any vacuum under boost (obviously) and if your accelerator got stuck down you’d have no vacuum (oops!) I’m using one of these on my EV conversion as the primary vacuum source. It’s not too noisy so yours may be worn out if the sensor that tells it when to come on is not functioning or if there’s a vacuum leak in the system. I’m sure you could find a good used one at one of the Volvo/European car wreckers as they were on a lot of the Volvos (for example S80T, C30/S40/V50 turbos to name a few) so you have a large pool of wrecks to choose from, as well as go for the newest one you can find. Try Berry Motor Group in Mitcham VIC or your local Volvo specialist.
  • MaxMax (@Max) Central Coast NSW
    Thank you CarNut,
    Pardon my confusion as I've never dealt with anything this technical.
    So normal aspirated cars have a vacuum in the inlet manifold, but turbos have the gases blown into them so there's no vacuum for the power brakes; hence the 'auxiliary vacuum pump'.
    Doesn't this mean it'd be running all the time, as mine is?
    I still am not sure what the answer is.
    Is the Sensor had the Fritz or,
    The loose fitting tube going into manifold confusing the sensor, or,
    Just that the Pump is shagged and not performing it's duty fully?
    It's a beautiful car and been well maintained all of it's 308,000kms. Perhaps the Pump is planning on retiring.
    Any more thoughts or confirmations are appreciated.
  • The pump only needs to run long enough to fill the brake booster to about 15-20hg.
    A turbo engine still produces vacuum just not under all conditions so the pump is an auxiliary source of vacuum rather than the main source.

    If you're not experiencing any issues with the brake booster function ie: hard pedal you can leave it "as is"

    The electrical connector you cleaned is a pressure sensor and check valve assembly so i would suspect that is faulty as the xc70s use a similar valve and it often fails and splits apart.
  • MaxMax (@Max) Central Coast NSW
    Thanks Timbo & Carnut,
    Pretty assuring. We really need the car this week - and my Sweety's C70 is having ign key barrel probs.
    I see UP28 pumps are fairly universal from Holden to Suparu to Volvo etc.
    So, I'll buy another one of these and install. I'll give Berry Motor Group a call.
    Also, we never use Silicone Elastic around petrol/carbies. What're your thoughts on putting an external ring of Silastic around the loose hose-to-manifold to seal it?
  • I think the external silastic would be fine provided you leave it enough time to set before starting the engine
  • MaxMax (@Max) Central Coast NSW
    edited June 12
    Aye Tim, I'll clean the area with contact spray and then seal it and leave it for 1/2 a day.
    Talking with Berry Motor Group now about replacing pump.
  • carnut222Greg S (@carnut222) Daylesford VIC
    Yes, I was going to mention that pump is also used on a lot of cars including the Commodores with I believe the direct-injection V6, and yep, it’s a Hella UP28 vacuum pump - universal for the most part although the wire connector on the end COULD be slightly different - not sure on that. As stated, the pump should DEFINITELY NOT RUN AT ALL TIMES, so if it’s running more than a few seconds at start-up, there is a problem with your wiring, your vacuum sensor or a vacuum leak in the hoses that lead from the pump to the brake booster or brake booster to inlet manifold.
  • MaxMax (@Max) Central Coast NSW
    Thanks all,
    We ( Nicola and me) had to pick her C70 up from Lupica Motors ~ 90kms way today; the C70 key barrel had stopped working.
    We drove the S40 and, as it has a slight oil leak, left it with Joe (Lupica) and when I get it back, will tell you all what was wrong re the UP28. The drive there was fine.
  • MaxMax (@Max) Central Coast NSW
    Aux Vac Pump Update -
    Got car back - Joe found a split in a hose under the manifold. Put new hose in.
    Unfortunately - when I got home (90kms) the pump was positively buzzing. Continuously running.
    So, I figger ti's the sensor. Figger the vac pump doesn't get a mention in the Onboard Diagnosis list.
    Joe had put his 'top o' the range' OBD on and found no faults. ( as I had done the previous week).
    My logic is: the vacuum is there and the sensor doesn't feel it and is telling the pump to go.
    When I turn the ign to 'On' the pump whizzes for about 5 secs. and stops. When I turn the engine on - the pump runs constantly.
    So now I'll be looking for a sensor. Any help would be appreciated.
  • MaxMax (@Max) Central Coast NSW
    edited June 21
    This's what it sounds like - but only when the motor is running.

  • MaxMax (@Max) Central Coast NSW
    edited June 25
    The latest ..
    Had a feel around the Vacuum Switch and found cracks and splits. Can't be good.
    I've painfully wrapped insulating tape around it and will test this arvo, hoping it will give the poor UP28 pump a break.
    Will report in tomorrow but it looks like I'm looking for a Vacuum Switchlwbv8cc80srr.jpg

  • MaxMax (@Max) Central Coast NSW
    June 22nd
    No improvement with insulation tape around sensor - didn't think it would seal anyway.

    So now hoping to find a reasonable 2nd hand one - without cracks. Otherwise ... I dunno.
  • MaxMax (@Max) Central Coast NSW
    June 23rd.
    Good news.
    Funny that it's good news that a part has broken - but
    Undoing the tape from the sensor this arvo and it broke!
    So - that is for sure a problem and I might glue it back together and encapsulate the join in silastic.
    But that's for tomorrow.
    Still, if anyone has a spare vacuum sensor I'd like to buy it ....h6i625dubhij.jpg
Sign In or Register to comment.