Leaking sliding window - replace or rebuild?

[Cruz]

A friend has just had their sills patched up due to the sliding window leaking over time and has asked me the question of whether they should replace the window and seal or replace the seal and refurb the window. I think it's an autosleeper

I've never had a sliding window out so I can't really advise them.

Would it be the window seal that has perished or can the rain get into the van through the frame?

Can sliding windows be refurbed....ie brush seals etc?

If a new sliding window is needed where can they get a new one from? (seems silly to spend money on 2nd hand that may be nearly as bad as the one they have?

[Plasticman]

the sleepers in common with other panals have a habit of letting in water here, your probably correct in all respects, i havent refurbed a window my self, fitted plenty though . you should be able to tell from the inside if its rotten rust under the rubber, they usually are in which case a new seal and clean/repair the van bit, at least with a nice new supple seal you can whip it out if found the window is at fault,
mm