Solution Number: 70021

Solution Summary: 8.1L CNG HFNO1->HFN04 Model - High Pressure Regulator Oil Contamination Cleaning

Publication Date: Oct 21 2013

**Paner copies of solutions may not be the most current solutions**
Complaint or Symptom :

Contaminate cleaning of high pressure regulator.

Problem or Situation :

Poor fuel quality can result in the passage of compressor oil into the regulator and cause the regulator to act
inappropriately.

NOTE: High pressure fuel filter should have been installed by OEM (Vehicle manufacturer) upstream of high
pressure lock out and regulator.

NOTE: High pressure fuel filter should have been installed by OEM (Bus manufacturer) upstream of high pressure lock
out and regulator. .

Solution ;
Please follow the steps outlined below for light cleaning of the regulator:

e If removing components. always follow CTM87 and other safety procedures.

e Drain excess oil from regulator by turning on its side and draining oil into approved container if possible.

e Research local, state, and government rules on use of concentrated isopropyl! alcohol to see if any special rul¢s-or
limitations exist. If isopropyl Alcohol is not restricted in your area you should proceed. If isopropy] is restricted.
you can not continue with the extra steps below.

e Use 91% or greater concentrated isopropyl! alcohol fed through the high pressure filter or upstream of the regulator.

e Apply a pressure higher than the set pressure of the regulator to drive the solution through the regulator.

e Collect the fluid drainage from the outlet of the regulator.

e Run air through regulator and other fluid impacted components at 250-400 psi air pressure for 10 minutes (@ 10ctm
to clear the cleaning solution.

e The regulator should be mounted so the outlet allows oil to drain from the regulator by gravity. The tower of the
regulator can be pointed up with the outlet horizontal, or the tower can be horizontal if the outlet is pointed down.
The outlet line from the regulator should also run downhill for a reasonable distance to allow any oil to stay clear of
the regulator.

e Reassemble parts per approved procedures.

NOTE: Cleaning and/or replacement of the high pressure regulator due to oil contamination is NOT covered under})"!
Warranty.:: ay

8/8/2014

Additional Information :

Reference DTAC Solution #70018 8.1L High Pressure Regulator and Compressor Oils for additional information if
needed.

608]

OIL, LEAK, CTM300, CHECK, NG, FLUID, POWERTECH, DEBRIS, PTS, RE500853. RE503870, ENG, F0400.
F0413

8/8/2014