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How to Pass the USPS 941 Automotive Bench Test

Eddie spent 35 years in the automotive business with Honda. He is an ASE certified master technician and has bruised knuckles to prove it.

The Grumman LLV

The Grumman LLV

USPS Mechanic Test

If you apply for an automotive mechanic's position at USPS, you'll be required to take the 941 Bench Exam if you pass the 943/944/945 Vehicle Maintenance Tests. All of these tests are part of working on the USPS delivery trucks, which are based on the chassis of the 1982 Chevy S-10 Blazer.

If you know how to work on this type of vehicle, you have a deep knowledge of auto mechanics and safe practices, and you have good safety inspection capabilities, you will have no problem passing these tests. The key is to take your time. They aren't looking for people who can do things quickly without reading manuals—they're looking for people who can do things slowly and carefully while consulting manuals.

I took the first three exams (the 943/944/945 Vehicle Maintenance Tests) all in one shot via the USPS exam site. These tests are computer-based, and you will need to find a test site close to your home. The 941 Bench Exam, however, is done at the USPS maintenance facility, and it's a hands-on test. You'll need to understand the five systems listed below on these vehicles to pass.

What Is the Grumman LLV?

The following is an excerpt from the Wikipedia entry for the Grumman LLV.

"The Grumman LLV was specifically designed for the United States Postal Service; Grumman won the contract to produce it. The main design points of the vehicle in contract competition were serviceability, handling in confined areas, and overall economical operation. As its name suggests, the Grumman LLV is easily capable of a long life, perhaps approaching 20 years of operation. The lifespan specified by the U.S. Postal Service was 24 years, but in 2009 this was extended to 30 years. The majority of LLVs have been on the road for over 27 years. The body and final assembly are by Grumman, and the chassis (based on the 1982 Chevrolet S-10 Blazer) is made by General Motors, with the powerplant (2.5L I-4 TBI 'Iron Duke' and, in later production, General Motors 2.2L I-4 iron block/aluminum head engine), instrument cluster and front suspension similar to those used in the Chevrolet S-10 pickup and S-10 Blazer sport utility vehicle. "

For more information, visit the vehicle's Wikipedia page directly.

What's on the USPS Mechanic Position Exam?

There is time allotted for you to read the instructions on the repair order, gather any tools you'll need to perform the objective, and read the LLV repair manual to prepare for the task. Each operation is timed, and you will be watched during each task. Take your time, and don't worry about the clock. You'll have plenty of time, so just work confidently and safely.

The instructor will be taking notes on how well you inspect the components, what you use for tools, and what questions you ask. I recommend that you ask as many questions as you need to so you understand the objective. I also recommend using the books and written material as needed. They want to know if you know how to look up information and use repair manuals. This job is not computer-based, and I'm sure you'll be hard-pressed to find any repair videos on YouTube for these specific vehicles.

These trucks are old and rusty in my part of the country, and the parts/components didn't come apart very easily, so I definitely struggled. It's better to do a thorough inspection of the system and complete half the task than it is to rush through a task to finish on time and forget to do a complete safety inspection.

Below, the five tasks on the exam are discussed in more detail, and relevant(ish) videos are included.

Task 1: Front Caliper Replacement

The first task will be testing you on your ability to remove a front caliper, inspect it for any loose, damaged, worn, or leaking parts, and reinstall it. You will need to measure the rotor thickness with a manual micrometer, so you may want to freshen up your ability to read a non-digital micrometer.

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Task 2: Brake Shoe Replacement

The inspector will have you remove the rear drum, inspect the shoes, disassemble the shoes, springs, and adjusters, then reinstall the shoes. You will not need to measure the drums, but don't forget to check the drums for heat cracks and pitting; these trucks are old. Also, don't forget to check the brake lines for leaks and the axle seal inside and outside the drum for leaks.

Task 3: Snap-On AVR Battery Test

You will need to know how to connect battery jumper cables correctly, not a jump box, test the alternator, starter draw test, and battery test using the snap-on AVR. You can find demonstrations on YouTube on how to use this machine, but it may not be the same as the USPS machine. The videos below include demonstrations of the snap-on ARV and jumper cables.

Task 4: Electrical Issue Diagnosis

There will be an electrical issue with the truck, and it will most likely be pretty simple, so I recommend you know how to use a test light and how to read the manual troubleshooting chart.

Task 5: Distributor Reinstallation and Engine Timing

The inspector will have you remove the distributor from the block, then they will crank the engine over once the distributor is removed. You'll need to find TDC and reinstall the distributor, start the engine, and time the engine with a timing light.

Take your time doing this and mark the distributor base with a scribe, then scribe the block. I made the mistake of scribing the distributor hold-down plate and found myself SOL when I installed the distributor. I had run out of time on this task and had never finished. I couldn't find the exact distributor replacement video for the 2.2L or 2.5L engines, but the video below should help explain the process.

My Best Advice

The best advice I can give you is to take your time and read the LLV manual on each operation—even if you think you know what you're doing. The inspector will grade you on how well you follow directions and if you can use the LLV manual as a reference/guide. They are looking for mechanics who have a solid understanding and acknowledge the fundamentals of automotive mechanics. They want their mail carriers to drive safe vehicles with minimal breakdowns.

So, how did I do on my 941 Bench Exam? I failed miserably. The inspector told me to take my time—it's not about speed or even finishing the procedure—they want to know if you can perform the job without killing yourself or harming anyone else that may be working next to you. You'll be working on the same vehicles day in and day out, so you'll get used to the problems and issues that are common, and the job will become very repetitive. Eventually, you'll be able to work on the Grumman with your eyes closed.

Let me know if you have any questions. I may have missed something here, but it all boils down to knowing everything I mentioned above, being smart about how you work on vehicles, taking your time, and being safe.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

© 2021 Eddie Carrara

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