Gates powergrip
These heat shrink hose clamps are the only clamps I use. Have never had one leak.

Gates PowerGrip SB Clamp Fits Hose OD 1 1/2 to 1 3/4 Nominal Hose ID 1 1/4
Part Number:gat32941
Description:PowerGrip SB Thermoplastic Hose Clamp
Hose O.D. Min (in):1.5
Type:Thermoplastic
Hose O.D. Max (in):1.75
Nominal Hose I.D. (in):1.25
Size:SB41
Material:Thermoplastic
Adjustment Type:Thermoplastic
Maximum Diameter:1.75
Minimum Diameter:1.5
Inside Diameter:1.25
Band Width:1.25
Hose Clamp Size:SB41