Can you seal the ac lines for the sleeper on a Volvo?

Sure you can cap off the lines but I wouldn't try it yourself, take it to the dealer and pay to have it done.

 

if its the fittings that are leaking you may be able to replace the o rings, if its the line itself best to replace them. on my old fld blew out a sleeper line in hot weather on a tight budget ended up cutting off the lines and soldering caps on them, and only had front ac with the little 42 inch flat top i found i stayed plenty cool like that and never did end up replacing the lines to the sleeper, a big volvo cab though doubt your going to get enough cold air from just the front.

 

This might sound mean but honestly if you can't afford doing that small repair Correctly and need to rig up junk you should evaluate your business maybe. Fixing a $800 issue the RIGHT way shouldn't be a problem.
Sorry man

 

Wrecking yard for the lines maybe.

 

if it has a rubber line toward the back run a bolt in there tight and put a hose clamp around I did mine like that 4 years ago an still in business I see no need for it back there my dash keeps the whole truck nice an cool

 

You can use a auto A/C repair shop that only works on only a/c most can use a small torch to weld any breaks in alloy lines and refit all rubber lines with damage for a tenth of what a dealer will charge to replace your lines?