Some vehicles equipped with a Heavy Duty 6.2L diesel engine (RPO LL4) may experience vehicle surge when descending a hill or in a deceleration mode. New parts have been designed to alleviate vehicle surge problems. The parts are available only through authorized Stanadyne Diesel System distributors and dealers. The parts include a new delivery valve spring and redesigned stop.
Description SDS NO. ----------- ------- Delivery Valve Spring 26071 Delivery Valve Stop 26070
Prior to removing a pump for repair, contact an authorized SDS distributor or dealer to ensure the new parts are in their stock. The injection pump must be removed from the engine for completion of repairs.
The new spring and stop will be included as standard equipment at SOP 1986 in 6.2L RPO LL4 engines. However, vehicles built prior to the 1986 model year will be updated with these new parts only on request, and the expense will not be handled under the terms of the Roosa Master Warranty.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.