NHTSA Office of Defects Investigation
Preliminary Evaluation PE12-030: Fuel Pressure Regulator Leak
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE12-030 on October 11, 2012 and closed it on May 22, 2013. NHTSA's investigations file lists the MR. GASKET CO. 9710 for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE12-030 (also written PE12030)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed May 22, 2013
- Opened
- Closed
- Vehicle or equipment manufacturer
- PRESTOLITE PERFORMANCE
- Components
- Fuel System, Gasoline; Fuel System, Gasoline — Carburetor System; Fuel System, Gasoline — Delivery — Hoses, Lines/Piping, and Fittings; Fuel System, Other — Delivery
- Vehicles and equipment
- MR. GASKET CO. 9710
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE12-030.
ODI directed the Vehicle Research and Test Center (VRTC) to purchase and test 30 subject regulators.
The regulators were marked 2011 and 2012 and were purchased from three separate sources.
Externally, the regulators looked similar.
Internally, there were distinct differences.
The 2011 regulators had a burr on the upper gasket seat edge and a casting flaw that formed a sharp edge on the lower seat.
Both of these cut into the diaphragm gasket.
The plating on the inside surface had a dull finish with loose, flaky particles that stuck to the diaphragm when it was removed.
The 2012 regulators were the same design but the plating was of a higher quality.
There were no loose particles and the seating surface was smooth.
VRTC found about half of the 30 units had at least one loose housing screw when received.
The first 10 regulators were tested with water at the recommended maximum inlet pressure of 8 psig.
Pressure was gradually increased to 100 psig.
This resulted in two regulators exhibiting a slow drip at the flanges; one at 70 psi and another at 76 psi.
To test the effect of loose screws on a regulator, screws were slowly loosened with the regulator at 80 psig.
The screws were completely removed and no water leaked.
The modulating valve had closed from the inlet pressure and no water could flow to the outlet side.
Additional tests with loose screws indicated the modulating valve would close at about 40 psig inlet pressure with the adjusting knob set at 5.5, and close at about 20 psig with the knob at 0.5.
After finding that higher pressures reduced the chance of major leaks, VRTC changed the test strategy to use lower pressures.
A diaphragm was punctured in one regulator.
This resulted in water flowing out below the adjusting knob.
In two consumer videos posted on the internet, fuel sprayed out forcefully between the flanges.
This meant the diaphragm was intact and fuel was leaking below the diaphragm gasket and between the flanges.
Tests were conducted with grooves cut in the lower side of the gasket.
This produced a slow drip.
The modulating valve reduced flow and pressure too much to produce a spray pattern.
VRTC tested regulators with a foreign object on the modulating valve O-ring.
This didn't open the valve enough to produce the spray.
The modulating valve had to fail fully open.
VRTC tested a regulator with the retaining ring for the modulating valve pulled loose.
With 15 psig inlet pressure and loose screws at the 6 and 12 o?clock positions, it produced the spray pattern seen in the consumer videos.
VRTC concluded that a loose retaining ring was the most likely failure mode for those two failures.
The retaining ring is a press-fit assembly.
It fits in an unmachined cylinder in the cast-aluminum regulator body.
The regulator was plated and the cylinder walls were coated in the plating process, which can leave an irregular surface thickness.
It is not a precision manufacturing process and some retaining rings may be pushed out if inlet pressures exceed the manufacturer?s maximum recommendation.
Prestolite reported low failure rates and claimed there was no reason for concern.
ODI doesn't agree that there is no reason for concern as Prestolite did receive four reports where the owner's concern was fire related.
Prestolite doesn't maintain ownership records or have a means to track production.
Prestolite did not seek further event details and no parts were available for ODI to inspect.
It is unclear whether the claims reported an actual fire or a potential fire.
Unable to contact the owners or inspect the failed parts, ODI must rely on available data.
No vehicle fires have been reported wit
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE12-030. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
MR. GASKET CO.
MR. GASKET CO. 9710
- model year not given
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE12-030
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.