BlackHawk SJ-2 Help with o-ring

[Bostopa]

Hi all have a Blackjack, has replaced internals a couple years ago was again leaking at front o-ring. So replaced but I know I got the o-ring rize slighly off.

Does anyone know what the actiual o-ring size is??

Its O-ring no. 62

 

[paulsomlo]

That's a Blackhawk, rather than a Blackjack. I have both the Blackhawk version (red), and the Sears branded version (green). If I'm remembering correctly, the two versions had two different ram diameters. My Sears version has a 1.125" diameter ram, and I'm not sure what the Blackhawk version has, either 1.25" or 1.5". If it's the smaller ram, the o-ring is probably 1 1/8" with a 1/8" cross section. With either size ram, the o-ring cross section will be 1/8". What color is your jack and do you have a means to measure the ram diameter? Also, what size o-ring do you currently have in there?

 

[Bostopa]

Used to be red...yes I can measure the diameter in the morning

 

[Bostopa]

Size is 38.22 mm or 1.5045 inches

 

[paulsomlo]

The o-ring is either going to be 1 7/16" ID or 1 1/2" ID, both would be 1/8" cross section and I'm leaning toward 1 1/2". In o-ring speak, that's a -221 (1 7/16) or a -222 (1 1/2).