STANADYNE®

34593 advance adjusting tool 

Diesel Systems

The 34593 advance adjusting tool is used for performing both the speed advance and

light load advance (LLA) adjustments on "Type 2" servo speed light load advance

(Reference S.B. 373R2) Target Series fuel injection pumps. Speed advance adjustment

is performed dynamically on the test bench, with the service tool acting as a "jacking"

screw to properly position the speed advance adjusting plug within the light load

advance piston. Adjustment of the LLA is accomplished by turning the LLA adjusting

screw (P/N 33614) with the 11mm hex on the end of the tool handle. Adjustment

procedures are outlined on the attached instruction sheet (P/N 34703).

The serviceable components of the servo speed light load advance adjusting tool

include the O-ring seals and a replaceable threaded tip on the end of the shaft. The

threaded tip is available as P/N 35333 and is packaged complete with a replacement

retaining pin. The location and part numbers of the O-ring seals are shown in Figure 1.

O-Ring Seal

P/N 27601

Screw

NO: 224R2

1950-2000

S OF DIESSE JNNOYAT

11mm Hex

Replacement Tip

and Pin Kit

P/N 35333

Shaft

O-Ring Seal

P/N 30911

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DESCRIPTION: SERVO SPEED LLA ADJUSTING TOOL INSTRUCTIONS

The 34593 tool is designed for dynamically adjusting the speed advance on Stanadyne fuel injection pumps

equipped with the Type 2 (Reference S.B. 373R2) servo-speed light load advance (SSLLA). The tool is

designed to act as a "jacking" screw to push or pull the press-fit speed advance adjusting plug within the

light load advance (LLA) piston. The opposite end is equipped with an 11mm hex for LLA adjustments

(performed statically). For the following procedures please refer the individual pump model specification

and Figure 1 below.

DRAWING NO .: 34703

REV. A D C B

11mm Hex for LLA

Adjustment

Figure 1

INSTALLATION: With pump mounted to test bench and at operational temperature:

1. Set speed to 0000 RPM, remove the LLA cap (P/N33044).

2. "Back out" all components of the tool (fully extend), but do not disassemble.

3. Screw part A onto the advance end plug assembly, until it seats against the O-ring.

4. Screw part B in until it stops against the LLA piston (finger tight only at this point).

Note: Ensure that parts C and D are fully extended to eliminate any interference.

5. Push part D in and screw into the speed advance adjusting plug until it lightly bottoms.

Note: Ensure part C does not interfere with the inward travel of part D. Adjust part C if necessary.

6. Tighten part B snuggly using a 9/16" wrench. This will prevent the LLA piston from moving during speed

advance adjusting plug position adjustment.

SPEED ADVANCE ADJUSTMENT: Bring test bench speed to required speed for speed advance

adjustment.

1. Hold part D stationary and turn part C with a 3/4" wrench to adjust speed advance.

a. Clockwise will push speed advance plug in, increasing spring preload and decreasing the speed

advance setting.

b. Counter clockwise will pull the speed advance plug outward, decreasing the spring preload and

increasing the speed advance setting.

REMOVAL: Bring test bench speed to 0000 ERPM.

1. Loosen part C two turns and unscrew part D until it is disengaged from the speed advance adjusting

plug. Note: Ensure part C does not interfere with outward travel of part D. Adjust part C if necessary.

2. Loosen part B a couple of turns.

3. Unscrew part A from the LLA end plug assembly.

4. Reinstall LLA cap, bleed air from system, and inspect speed advance operation.

LIGHT LOAD ADVANCE ADJUSTMENT:

With adjusting tool removed, determine LLA setting per service specification.

1. Set test bench to 0000 ERPM and remove LLA end cap (P/N 33044).

2. Engage the 11mm hex on the end of part D with LLA adjusting screw.

3. Turn LLA adjusting screw "in" to decrease LLA setting and "out" to increase LLA setting.

4. Reinstall LLA cap, bleed air from system, and inspect light load advance operation. Repeat if necessary.