Mack Trucks MP8 — Mack MP8 User Manual

REPAIR INSTRUCTIONS, PART 3 EXHAUST VALVE AOJUSHMENT (WITH +BOCKER POWEFLEASHTT) NOTE The Ўumbe6 oЎ the camshalt preceded by a v ae used lo adjust lhe exhausl valves when lhe eЎgine is equipped wlh Pore -eashrM, Using lhe lwhed lurning lool,98800014, bar lhe engine over so thal the appropriate V numb3r mafkinq lor the respeclive exhausl valve is be1{een lhe lines on lhe cacshal I. Press down on lhe rockйr arm бs shown in Figurй 439. ll the rocker arm spnngsi the bЙkй p sron spring should be pul ed ourwad al ihe same lime 4 lhe r@ker arm is p€ssйd d@n lo make бnd ensъre @ntact wilh the valve slem. Use a sl@ng wie wilh a hooked end lo @lch and comprбss lh6 spring.

When the pislon spring is loosйned tom its sear, rhe residual oil iilm €raininq lhб 6pr ng is punclur€d, allowing adJuslment selЎnq to be moE accufale. 4. lf clea.ance is nor withic specii cation, adjusr ье clйaEncй as rcquned, lsing shims (Fiqure 441) plбced ус top ol lhй vбlv€ yyk6 a. Femove rhe shim fetainЎng screw and Emove lhй shim(s). b, Delйrminй lhe rhicknessotlhe shim(s) йquifed to malch lhй measurйd 6. Make sure lhai lhe vd@ yoke and shim(s) are 6lean. Place rhe shim(s) in position on lhй valve voke. NOTE DO NOT use сой lhan tuo shims. Shims are aEilable in 0,05 mm (0.002 inch) increnerns with lhй lhickness ma*ed on lhe suЎtїce.

lt Nlo shims are requir€d io lбk6 up lhй cleaance, the shims should be ol neadv equal thicknйss. S- 3. Measurб ье cleaEnce belweeЎ the @ckeЎ ah pislon and the shim on lop ol thй yoke lbridoe) as sh(M in Fioure440. FЎquE er Enqrnї conpEsЎon BFh. adiu.rъ6Ў