1998 v70 2ndary Air Pump Frozen Already

Post by **MrAl** » 03 Jun 2015, 12:23

Hi,

Some bad news. The brand new air pump i installed just two months ago has frozen up already. I checked and there was a little water inside the pump. I didnt think it could happen that fast.
I was also a little afraid to drill a hole in the bottom because it was new and cost so much, so i did not have that advantage.

I finally was able to get the hose off of the vacuum air control valve, which connects to the air pump by hose, and it seemed to be blowing a light wind out of it at all times, which i think means it is jammed open. Lots of dirt in there too, like from stagnant water that had dried up.

What i didnt realize when i first got the car was that when the air pump is changed it is almost mandatory to change the vacuum air control valve also, or this could happen. I thought i would have time to troubleshoot it before it froze up.

Checking the electrical properties i could see that the brushes must have had something between them and the commutator of the motor, possibly some of the dirt from the dirty water.
After uninstall and bringing in into the house and checking more carefully, i found i could turn the armature with a pair of pliers to get it free. Once done, the motor runs again, and the electrical readings look normal again, but i fear it may freeze up again.

So what do you think the chances are that it will freeze up again if the vacuum air control valve is also replaced so there isnt any water anymore, and also the small recommended hole in the bottom?
I could let it dry out thoroughly before i install it again if you think that will help.

Thanks.

The only good thing is i was able to get the hose clamp off finally, with a battery operated Dremel-like rotory tool. I found that if i grind most of the way through i could break the remaining thin metal apart with a sharp bladed screwdriver and thus avoid damaging the hose.

Post by **erikv11** » 03 Jun 2015, 14:13

Yeah, the reason the pump fills up with water is because the SAS valve is bad. You must replace the valve. So few people replace these pumps any more, that detail must have fallen through the cracks on you.

With a new SAS and a small hole drilled, the odds are very good for air pump longevity.

Post by **misha** » 03 Jun 2015, 16:26

Yep...you will need to replace sas valve too.
For those two months with bad sas valve,you should had a code for sas system.

Post by **scot850** » 03 Jun 2015, 19:51

Unfortunately an expensive lesson. The valve failing open is the reason the SAS valve fails. I had about a pint of water in my 98 XC SAS pump when I removed it. I recommend drilling a small 1/8" hole in the casing bottom to allow any condensation to drain out.

My car never threw any code for this problem, even when I removed the valve ad checked it it was jammed open.

Neil.

Post by **cn90** » 03 Jun 2015, 20:38

1+,

The Air Valve is the usual culprit.

Time to get rid of the SAS system and install the 90-cent diode mod.

Post by **MrAl** » 04 Jun 2015, 02:50

Hi,

Thanks to all for the replies. It is good to hear other peoples stories when something like this happens.

Yes, i know i should have done the diode trick, but i thought i would try first to go fully legit and save that for a last ditch effort. I was also a little afraid to try that because i dont know much about the car yet, and am learning little by little.

Needless to say, i'll drill the hole and replace the valve, then go from there. I just have one more little question...
There is also a check valve that i can replace, but there is also one more 'valve' and that is the solenoid valve. The solenoid valve is the one that is electronic, and that allows the vacuum to flow in order to open the vacuum valve (the one close to the exhaust manifold). It is mounted right under the very front of the hood right over top of the front grill almost, with two wires running to it and two vacuum lines, one line going to the vacuum valve and one i think goes to the intake manifold, or maybe to the check valve that then goes to the intake manifold. What are the chances that this last valve is bad too (the electronic one) ?

Thanks again.

Post by **jreed** » 04 Jun 2015, 03:49

I haven't heard of any reports of the electronic solenoid valve going bad. You could test yours and if it is bad you can pick up a spare one from the junkyard.
I also had a bad main air pump about 10 years ago and I replaced it and the SAS valve at the same time... At the time, I took the precaution of drilling a small weep hole at the base of the pump outlet. So far so good.

Post by **cn90** » 04 Jun 2015, 08:43

In my 1998 BMW 528i (same SAS setup):
- The Air Valve is kaput at 110K.
- The electronic solenoid went south at 130K.

The 1998 Volvo, irrelevant now b/c I installed the 90-cent diode.

Post by **erikv11** » 04 Jun 2015, 09:09

Ditto to jreed: I've never heard of a failure of the solenoid on the Volvo forums. And remember, everyone using the diode still has the solenoid plugged in and functioning, so the solenoid is still widely relevant. You are fine with that one or at the very worst just get a junkyard replacement.

Post by **cn90** » 04 Jun 2015, 09:54

Once the 90-cent solenoid is installed, the small electric air valve, the main air valve (sitting on the exhaust manifold) and the failed air pump are just worthless items sitting around doing nothing.