1998 v70 Secondary Air Pump Internals (Pics)

Post by **MrAl** » 02 May 2015, 14:10

Hello there,

I decided to take apart the old secondary air injection system air pump just to see how they made it and why it might be so expensive in some places (like $600 USD).

It isnt that complicated. Just a thin blower fan (mini turbine) and a motor, and some bearings and a spring and connector, and of course the housing.

I had to drill the tops of the rivets to get the top off, and the bottom where the motor was came right off with the tabs.

The pics are shown in the attachments just in case anyone else wants to see the internals. The spring goes on the back of the motor between that and the back of the case where the wires come out. This particular model was the ORIGINAL dated 1998, and has raised lettering that reads, "Pierburg".

If you look at the top (the pic with the big round rusty thing) you'll see the fan blade part, and if you look at the center you'll see a beat up shaft or something in the middle. It looks like it is pressed on or something and if no one here knows how to get that off i'll have to grind it off, just so i can get it completely disassembled for better viewing of the entire thing. I tried turning the fan with vise grips but it wont turn as the bearings must be completely frozen from rust.

So if anyone knows how to get that off that would be nice, or else i'll grind the heck out of it until it comes loose.

The motor is pretty big, maybe bigger than the windshield washer motor, but i dont have any specs on the speed or torque or anything like that.

: Enclosed Fan Blades.

: Motor Back, Spring Removed.

: Spring.

Post by **matthew1** » 02 May 2015, 15:31

Thanks Al. I'll put this in the Repair Database.

Post by **MrAl** » 02 May 2015, 15:45

Hi there Matt,

Oh ok great. One thing though, i dont know if this unit is truly repairable yet or not. We'd have to be able to get a motor i guess, and maybe some bearings. I havent figured out how to get the fan blade off yet though, and it looks somewhat fragile, so i am not sure if this can ever actually be repaired. I wanted to take a look inside anyway though

Post by **jreed** » 03 May 2015, 06:22

Great images of the internals. I've only taken one of them apart before (see link below to images), but it didn't have as much rust as yours did. Interesting! It looks like yours was sitting half-full of water for a time. Thanks!

Air pump fix tutorial volvo

Post by **MrAl** » 03 May 2015, 09:24

Hi,

Yes, it's nasty looking and fully rusted up so nothing turns at all.

The pump was not even on the car when it was purchased, i had to ask the guy to find it and give it to me so i could see what one looked like, and also to get the bracket that goes with it which is required for mounting the new pump.

I have read that condensation from a faulty 'control valve' can cause the bearings to freeze up, but this almost looks like it was in a flood at one time.

Post by **cn90** » 03 May 2015, 10:51

I posted procedure on how to remove the impeller in forum.

However, most of us have moved on using the 90-cent Radio Shack diode mod.
Don't waste time fixing this air pump.
Newer Volvo, BMW got rid of the air pump, cold start pollution is now modulated using valve timing.

Post by **matthew1** » 03 May 2015, 11:53

MrAl wrote:Hi there Matt,

Oh ok great. One thing though, i dont know if this unit is truly repairable yet or not. We'd have to be able to get a motor i guess, and maybe some bearings. I havent figured out how to get the fan blade off yet though, and it looks somewhat fragile, so i am not sure if this can ever actually be repaired. I wanted to take a look inside anyway though

Yep. I'm putting this in the VRD for its reference value. The VRD is either misnamed, or its contents have grown beyond its name

.

Post by **MrAl** » 03 May 2015, 12:38

cn90 wrote:I posted procedure on how to remove the impeller in forum.

However, most of us have moved on using the 90-cent Radio Shack diode mod.
Don't waste time fixing this air pump.
Newer Volvo, BMW got rid of the air pump, cold start pollution is now modulated using valve timing.

Hi there,

I found your well written procedure here:
https://www.matthewsvolvosite.com/forums ... 3&p=146467

Very nice. I see the motor and bearings were identified too already, very nice.

I didnt really plan to fix this one unless it turned out to be really simple, as i already bought a new one and installed it, but just wanted to share some pics of this thing and what it looks like inside.

I am not sure i have the guts to try that diode mod. I actually studied electronics and related for more than 40 years both in college and in my own time, and when i say in my own time i mean for years and for hours per day. I have seen things go wrong which then turn out to be hard to fix. If anything went wrong with the diode trick i wonder what the consequences on the electrical system would be.
Also, i saw two different fixes where one had the diode in the wrong place. I cant afford to make a mistake on that.
I am not even sure where those electrical connections are found, maybe you can describe a little?

Still it does sound interesting. That pump has been a pain since day 1. After the new pump install the OBD2 read, "OK", right away, but then after clearing the CEL and then about 40 miles later with headlights on and idling, the CEL light came on again with that same P0410 error code. After replacing the air filter and clearing the CEL again, it came on again about 5 miles later, with headlights on and idling.
BTW nice to see the spec's on the pump motor. That tells me about the current draw which is good to know when testing the pump externally with a power supply.

Post by **cn90** » 03 May 2015, 19:23

Don't worry about the diode mod. Tons of people in this (and other) forum did it.
Zero problems.

Post by **MrAl** » 03 May 2015, 20:19

Hi again,

Thanks for the vote of confidence, but where exactly is the board or whatever it is that get modified? Is that one of the control boards, and if so, where would i find that in the actual vehicle?

BTW i got my old pump apart finally. Just wanted to see what was in there really. I see there are two impellers not just one.
Everything was so rusted up it took a couple hours to get that apart the rest of the way because everything was frozen to the shaft. I can see why no one wants to repair these things...that and the motor replacement could be around 80 bucks too.

Thanks much.