Pump Trouble

My old Ford Explorer has been a surprisingly reliable vehicle, even now with nearly 200,000 miles behind it. True, it is showing its age and there are a few things that do not work. It still gets decent gas mileage, has not soaked up much cash for repairs, and has always gotten me home. The vehicle continues to get me to work and the beach, what else can I ask for?

OK, have to scratch the get me home part.

At least it failed in the parking lot at Keck. Lots of cranking, no ignition, no fuel. And it fails on a Friday afternoon, when I fly to California the next morning. So the vehicle sits at work for a week.

When I do get a chance to work on it, I quickly determine the issue is the fuel pump. There is no gas getting to the engine. No problem, I can fix this one.

Get the vehicle towed home, jack one side up and drop the fuel tank. Of course I had a nearly full tank of gas when the pump failed. Murphy strikes again! It is necessary to get the gas out of the tank before removing it from the vehicle. I had to siphon the fuel out, a slow process to remove twelve gallons. Not having enough gas can capacity I had to dump it somewhere… I wonder if my wife will figure out why she got such excellent mileage out of her last tank.

Pulling the Tank
Pulling the fuel tank from a 1995 Ford Explorer

The tank is actually pretty easy to remove, a handful of lines, one cable and seven bolts need to be removed. The only real problem I had was that the bolts had not been removed since the vehicle was new, 18 years ago.

Every single bolt was a struggle, using my full strength to back the bolts out, 1/6th of a turn at a time. I really need to consider the purchase of an impact wrench. What took two hours to get out took 20 minutes to get back in once all of the bolts were out, cleaned up and hit with a little WD-40.

When I pulled the original pump out of the tank I grabbed a 12V battery pack and tested it. No problem, the pump starts right up? I also check the wiring, some of he connectors are a bit corroded, though not horrible. I clean those up and grease with silicone contact sealer.

Pulling the replacement pump from it’s box I also connected it to the battery. I was not impressed. The new pump ran rough, sounding rough and vibrating notably in my hand. The motor was clearly poorly balanced or the quality of the bearings suspect. This was not a part that I wanted to put in my vehicle. I have learned the hard way to check the quality of repair parts from the local NAPA Auto Parts. Some parts are fairly decent, others are suspect, perhaps victims of intense cost pressures.

I decided to re-install the old pump, despite being suspect. It was running smoothly in my hand, a more attractive option than the piece of $@%#! replacement. (Sorry, in these situations a little swearing is going to happen.) With everything put back together the vehicle started up just fine, a smoothly running engine music to my ears. Sure, there was that moment of cranking needed to get the air out of lines that had been opened, but it was only a few seconds of doubt and worry before the engine caught.

I drove to our local market, to the post office and to Waimea without problems, the pump was working just fine. I drove to NAPA to return the replacement pump and get my $157 back. I then drove to work. It was only after spending the day at work that the pump decided to fail again. Time for a little more swearing. Again I was sitting in the parking lot at work with a inoperative vehicle. I grabbed my bag and caught a ride home with one of the guys who lives in the right direction and considered what I had to do now.

A conversation with Mike, our fleet mechanic at Keck with years of Ford training and experience, confirmed my thoughts. The pumps will do this, start up just fine after being taken out or given a good whack, then fail again in short order. A bad spot in the brushes?

Sure enough, shorting out the pump relay and giving the tank a couple moderate thumps with a hammer resulted in a purring sound. Putting the relay back the vehicle starts up just fine. Now if only I figured that a few days ago… Grumble. Just put it down to lessons learned. At least I didn’t need to have the vehicle towed home again.

A better pump is now on order, or at least a pump from a manufacturer with a good reputation in various online forums. The pump costs less, with free delivery, than the piece of junk I had purchased at NAPA. I will have to pull the tank again, but I expect it to be much easier this time, the bolts should not be an issue, and I know the process.

Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.

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