With the Allison the parking brake is on the drive shaft. The hydraulic actuator that releases the spring tension has a bad seal and I can't find where to buy a seal kit. Any help would be appreciated. It is a Haldex and GM put it in a bunch of 16000lb plus chassis. This is in a 2001 C6500. Here is a complete new old stock one on eBay. Don't look like the make it any longer! I don't want to buy a complete one if i can just get a $20 seal somewhere.
http://www.ebay.com/itm/291447902888?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/291447902888?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT