8. Kuti udzivise kukuvara kwemidziyo kunokonzerwa nekuremerwa, kune yakawandisa otomatiki yekuburitsa valve mu hydraulic mudziyo. Kana chinhu chakadhonzwa chichipfuura mutoro wakayerwa, iyo overload valve inozozviburitsa otomatiki, uye yakasanganiswa hydraulic puller ine tonnage yakakura inoshandiswa panzvimbo.