46 is slidably disposed in housing 22 upward travel thereof limited by the abutment of keyway collar 40 against annular shoulder 48 crossover sleeve assembly 46 includes seal sleeve 50 carrying o rings 52 thereon which is secured to crossover body 54 by threads 56 crossover seal 58 interposed therebetween crossover tee 60 having t shaped passage 62 therethrough is an integral part of crossover body 54 and return mandrel 66 is secured thereto at threaded junction 68 crossover apertures 70 in crossover body 54 are aligned with the horizontally disposed outlets of crossover passage 62 while return mandrel 66 communicates with the bottom outlet thereof o ring seal 72 is disposed about crossover body 54 below apertures 70 j slot housing 74 from which annular shoulder 48 protrudes is secured at threaded junction 76 to crossover body 54 o ring 78 effecting a seal therebetween longitudinal keys 80 extend radially from j slot housing 74 into keyways 44 to prohibit mutual rotation between crossover housing 22 and crossover sleeve assembly 46 below annular shoulder 48 first j slots 82 are cut into the exterior of j slot housing 74 j slots 82 having open bottoms 84 see fig3 which communicate with lower seal surface 86 carrying o rings 88 thereon at the lower end of crossover assembly 12 return mandrel 66 is secured at threaded junction 90 to seal body 92 which carries o rings 94 thereon the interior of seal body 92 includes upper return bore 96 having.