retroactive disability check?

My brother was disabled a while back and applied for disability. It took them almost 2 years to finally approve him. The lawyer was paid almost immediately. He has been waiting since January for his retroactive check. The lawyer already got paid so basically won't do anything to help now. Disability keeps telling him he will get it eventually. Is there anything he can do to expedite this? Does this normally take 6 months to get the retroactive check? Do they have a time limit to sending this check? Any information would be good so I can give him some good news. He has been in rough financial shape since losing his job and having almost no income for almost 2 years. He lost his house, both cars and motorcycles because he could not afford them. He has completely screwed his back up. He paid into disability since he was working since he was 15. Are they really that backed up at social security, or they just can't be bothered to hurry?