that small vent hose going from the rear axle. where does the other end connect and what is its purpose. can a plugged hose cause leaks at the pinion seal and pumpkin cover gasket similar to a plugged pcv system causing engine seal leaks. its a 89 240 auto but not sure what rear axle i have.

The hose vents into a void in the frame rails. Look just above the axle vent tube--I think the hole has a rubber grommet. Don't plug the vent. Run a hose up somewhere else if you can't find the original spot. -- Dave

i see the grommet your talking about where the other end goes into. so after the grommet it just vents into the frame. can i replace the hose with a rubber one instead of plastic. you said dont plug the vent hole on the axle. what will happen if i put a plug over it. does it vent excess heat. it seems like a small hose for that. do you know its purpose. i have alot of questions and more experienced volvo owners like yourself have really helped me learn more about these cars. thanks. - Drew

The hose vents air pressure to avoid leaks from the seals and cover gasket. The hose needs to be able to stand up to oil/oil vapor. -- Dave

thats crazy. i went back out to remove the hose. i tried to blow air through it and it was plugged. my rear axle has been leaking from the cover gasket and more recently from the pinion seal. do you think i should still replace the pinion seal and cover gasket or will the new hose cause the leaks to stop. -drew

There's only one way to find out--and that would be easier than changing the seal and gasket first---you'll still need to clear the passageway. Maybe a vacuum could suck out the blockage. I'd use an open safety pin--has something to hold onto while probing and thin enough blade not to knock the plug into the axle tube all in one shot.
If your car has a stamped steel cover on the pumpkin (they can and do rust through) I'd look to replace it with an aluminum one from a later car (which I have done) -- or buy a chromed one (for Jeeps-cheap) listed in JCWhitney (which I have not done). -- Dave

even though i replaced the hose, where the hose connects can be plugged also. thanks alot for this info. i might use a small drill bit or paper clip. - drew