TM-5-3805-254-14-P-2

TRUCK, DUMP, 20 TON, 6X4, ON-OFF HIGHWAY 71,000 GVW, IHC MODEL F-5070 (CCE)

TECHNICAL MANUAL; OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT AND DEPT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS INFORMATION AND SUPPLEMENTAL MAINTENANCE INSTRUCTIONS)

JUNE 1980

TM-5-3805-254-14-P-2 - Page 526 of 894

TRUCK SERVICE MANUAL

Calibration Test Equipment

Cummins ST-848, ST-775, and ST-445 (with ST-773

conversion) fuel pump test stands have the following

features to provide accuracy:

1.

Large dial, laboratory accurate gauges.

However,

gauges are only accurate if properly maintained and

should, therefore, be checked at regular intervals.

2.

Accurate tachometers, either electric on ST-445, ST-

775 and ST-848 or hand tachometer ST-774 for use with

ST-445.

A digital tachometer is now In ST-848.

3.

A flow-meter, which permits the tester to adjust each

fuel pump for total flow and correlate it with pressure

calibration.

The "fuel manifold pressure" thus obtained

on the test stand will duplicate fuel manifold pressure on

the engine.

Test Stands

Cummins fuel pump test stands equipped with a flow-

meter are ST-848,ST-775 and ST-445 (with ST-773

conversion kit.) These test stands provide the most

accurate method of

calibrating the PT fuel pump, but due to some older

engines being built on special, "one time" orders cannot

be applied to all engines which have been built with PT

fuel pumps.

Test Oil

Cummins fuel pump test stands must be filled with clean

Cummins Test Oil No.

99011-68 or equivalent since all

calibration data has been established using this test oil.

Note:

Hydraulic oils are not suitable to use as test oils in

Cummins test stands.

Duplication of factory test methods and materials is the

key to correct calibration and insures uniform results

wherever the fuel pump is adjusted.

General Requirements

The material shall be a straight oil or a blend of oils

containing parafinic, aromatic

or naphenic compounds,

but not olefininc compounds, which show little or no

change in physical properties during storage or use.

The

use of various additives and/or inhibitors to stabilize the

oil is left