Underhood Over / Under Pressurizing Except "G" and "Lite" Systems

Technical Support Subject Underhood Over / Under Pressurizing Except "G" and "Lite" Systems Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-VR-004 A Tech Document Release SP 18 Sept 2015 DB 18 Sept 2015 N/A 18 Sept 2015 Page 1 of 4 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 System or Parts affected  Underhood70 (V900xxx)  Underhood150 (V910xxx) This document is not compatible with “G” or “Lite” systems Index System or Parts affected.............................................................1 Overview .......................................................................................1 Before you start............................................................................2 Over-Pressurizing ........................................................................2 Symptoms .................................................................................2 Resolution .................................................................................2 Under-Pressurizing ......................................................................4 Symptoms .................................................................................4 Resolution .................................................................................4 Overview This document explains how to trouble shoot both Over-Pressurizing and Under-Pressurizing issues with all VMAC Underhood Compressor systems Except “G” and “Lite” Kits. Figure 1 Airflow into inlet valve 1) System air pressure from Air Oil Separator Tank (150 psi) (C) Inlet to Compressor O-ring seal (B) 2) Regulated pressure (50 psi) applied to the Poppet 3) Mechanical force applied to close the Poppet ¼” Scavenge port Poppet Valve (D) Poppet O-ring (A) Technical Support Subject Underhood Over / Under Pressurizing Except "G" and "Lite" Systems Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-VR-004 A Tech Document Release SP 18 Sept 2015 DB 18 Sept 2015 N/A 18 Sept 2015 Page 2 of 4 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 Before you start  Observe all safety procedures relating to moving belts, hot oil and compressed air. Use all safety equipment to protect yourself.  Hot oil can cause severe burns  If the system has been operating, shut it off and wait at least 30 seconds for the air pressure to vent before performing service. Over-Pressurizing Symptoms Safety Relief Valve blows, Vehicle RPM’s not reducing, Oil leaking from fittings or light coating of oil in engine bay, oil leaking from between inlet and compressor after shut down. Resolution 1) Connect VMAC Test Tool (P/N# A700052) directly to Air Oil Separator Tank (AOST). 2) Confirm 200 PSI Safety Relief Valve (Underhood70 P/N# 3600054, Underhood150 P/N# 3600073) is functioning correctly. If valve blows before 200 PSI replace it 3) After proper function of Safety Relief Valve is confirmed adjust the regulator to intended pressure (Range: 110 PSI – 170 PSI). 4) Confirm Pressure Control line (1/4” PTFE or older steel ‘brake line’ style) is not kinked, blocked or disconnected or frozen. a. If Pressure Control Line is older style steel line we strongly encourage upgrading it with our PTFE conversion kit (P/N# A700153). (Figure 2) b. If freezing is a problem consider installing our De-Icer (P/N# A700031). Figure 2 5) Confirm we are getting full system pressure (Approximately 150 PSI set from the factory) from the AOST to the inlet via the Pressure Control Line by inserting a “T” fitting and 200 PSI pressure gauge. (Figure 3) 6) Confirm we are getting 50 PSI at the back of the Poppet piston by removing the 1/8” NPT plug at back of inlet and install a pressure gauge. (Figure 3) Technical Support Subject Underhood Over / Under Pressurizing Except "G" and "Lite" Systems Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-VR-004 A Tech Document Release SP 18 Sept 2015 DB 18 Sept 2015 N/A 18 Sept 2015 Page 3 of 4 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 Figure 3 7) Check for leaks at all fittings, the Scavenge Line and the AOST. 8) Confirm that the screw in the front of the Poppet is tight and the O-ring is in good condition (not cracked etc.) and properly seated (See a. and b. below). a. Many of our compressor configurations will require you to remove the inlet from the compressor to perform this inspection. b. Heat the hex head cap screws holding the filter plate on to prevent stripping them. (Figure 4) Figure 4 If the O-ring requires replacement and the Poppet has square edges then replace the Oring with P/N# 5830129. If the Poppet has chamfered edges then you will need to upgrade the Poppet and Valve Seat to our newer style with P/N# A700163. 9) If the above steps do not resolve the issue please contact VMAC Technical Support and have your System ID ready “T” into whichever side is not plugged We should get 50 PSI here. Pressure Control line to back of AOST Heat the hex head cap screws before trying to remove Confirm Poppet Oring is properly seated and in good condition 0-250 PSI pressure gauge Technical Support Subject Underhood Over / Under Pressurizing Except "G" and "Lite" Systems Document Version Department Revision Details Revised by Tech Engineering Implemented EXT-VR-004 A Tech Document Release SP 18 Sept 2015 DB 18 Sept 2015 N/A 18 Sept 2015 Page 4 of 4 Knowledge Base: www.kb.vmacair.com Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Toll Free:1(800)738-8622 Fax: 1(877)740-3201 Under-Pressurizing Symptoms Lack of tool Performance, Vehicle RPM’s can be either low or high. If the system builds pressure properly once but will not build pressure after air is used check the bleed hole on the front of the regulator for obstructions. Resolution 1) Connect VMAC Test Tool (P/N# A700052) directly to Air Oil Separator Tank (AOST). 2) Try adjusting the regulator to the intended pressure (Range: 110 PSI – 170 PSI). 3) Remove the air filter cover and air filter. Please ensure that you are wearing appropriate Personal Protective Equipment as there is a small chance that hot oil could be ejected from the inlet valve during the following test. 4) Using a screw driver push the Poppet open with the vehicle running. a. Check the bleed hole on the front of the regulator to make sure it’s not plugged. b. If the system builds air replace the regulator kit using P/N# A700137 5) If the system does not build air pressure when the engine is running and the Poppet is pushed open call VMAC Technical Support and have your System ID ready. | Freezing | ice | deice | cold | de-ice | frozen | underpressure | overpressure | overpressurizing | underpressurizing | freeze