97 850GLT air injection pump bad again??

My secondary air injection pump was already replaced once
(a year or two ago). Now it's sounding like a blender full of
rocks when it runs. So far the Check Engine light hasn't come
on, so I guess it's still working. Is there any way to lubricate
or service it somehow? If it's failing again, is there any generic
air pump that will work, or must I buy the $600 Volvo model?
Anything that costs that much should be designed to last for
many years, but I wouldn't be too upset about paying (say)
$50 or $100 for a new generic pump every couple of years.
Thanks.

 

A little more than a year ago mine started to make noise (98 V70). I
took it off, there doesn't seem to be any way to dissemble it without
destroying it. I filled the air pump section with transmission fluid in
the hopes some would get into the bearing. I let it sit overnight, then
reinstalled. It's still noisy, but still functional. Also the check
valve, the one that's supposed to close the path from pump to exhaust
was not closing properly. This allows condensation to collect in the
pump, which ruins it. As a final measure, I drilled a small hole in the
bottom of the pump to allow any water that did get in to drain out.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)