Air pump notes - 97 850 GLT

[chuckcintron]

There are five critical components in this system (on my 850 at least...assuming yours is similar):

1. The air pump
2. The SAS valve
3. The air pump motor relay
4. The SAS valve control solenoid
5. The piping system (air and vacuum hoses)

From what you describe, you could still have a failure at the solenoid, which has nothing to do with turning the air pump on/off. The purpose of the solenoid is to open or close the SAS valve, both allowing fresh air to blow into the exhaust system and to prevent exhaust blow-back into the air pump (when off).

The solenoid is easy to test. Remove it, and hot-wire it directly to a 12VDC source (jumper to the battery is fine). Blow into it while you energize it -- you should clearly be able to detect "open" versus "closed".

If you verify that *everything* on the above list is working correctly and you are still getting a P0410, then let us know. The air pump (out of spec) would be the next culprit...or a bad cat (which should throw other codes as well).

-Chuck

[volvoman9]

Thanks for the offer. I'll let you know how it goes. 130 K mi.

[volvoman9]

Yeah, go ahead and reset the code and see it it comes back. If that doesn't do it, replace the elbow or like I did, just replace the entire line with a small bore silicone line. I think I have some spare I could send you if you need it.

Well thanks for the offer. I had the light reset and all was good until today. It's back on so I'll try the elbows and see if that helps. I don't know what else to look for with a 410 code indicated.
130

[Disney_Volvo]

I encountered the same difficulty in bolting the SAS valve. The nut closest to the firewall is almost impossible to tighten with a wrench. However, if start with the nut closest to the firewall (save the outer for last), you can tighten it by rotating the SAS valve and holding the nut in place with a wrench. Once tight, the outer nut is easy. Hope this helps future shade tree mechanics.

[1997volvo850]

I've managed to replace my air pump just fine. Old one was full of water so I believe this means
the SAS Check valve replacement is a must.

Question: Is there a significant quality/functional difference between the $150 OEM valve
and the $75 aftermarket valve?

How in God's name do you get the check valve off? What tools fit into that tiny space? I'm assuming you
come in from the top. I can't get the back bolt to budge with medium pressure. Don't want
to break it. Need some expert advice.

Noticed that someone used the wrong screw to attach the old air pump -
and I don't recall ever having the air pump serviced. Somewhat annoyed by this
as I can't find a screw that fits. How difficult is it to get a few screws for my
air pump mount?

[randrews80]

Just replace my air pump and SAS valve about a month ago. It was a very easy project. I had purchased my v70 used with 62K on it. After my recent air pump replacement I went back through my records and found the the dealer had replaced it before at 72K. This being said I don't think that OEM valve is necessary - it didn't hold up all that well.

I got an aftermarket from FCP Groton for $60 and plan to change it every 70K. This was just a poor design by Volvo.

To get the valve off I used a 10mm articulated stubby ratchet wrench (Sears for $12) to get to the two bolts holding the valve on. It was a lot easier that I was expecting. First I sprayed some PB Blaster on the bolts. One note is to check the hose going from the valve to the air pump first. Mine had become hardened due to heat and oil over the years and crumbled when I removed the valve. Luckily there was enough left for me to tape it on to get a good seal (will replace during next maint. cycle).

Don't know where to get bolts for Air Pump - they looked standard - try any auto parts store.

Good luck.