One of the worst I have seen

[Jeremy airjer W]

I'm always curious to see what failed when a fuel pump stops working. I posted an article about this in the past but this one is to good not to share.

This came out of a Lincoln Town Car yesterday. During the testing process I found good power and ground to the pump and the pump ohm tested way out of range (3.5 mega ohms - A good pump is around 4 ohms). The pump was replaced and the vehicle was again up and running.

As you can see the insulation has melted seizing the motor. I was so bad the brushes had to be broken away from the armature.

 

[delcecchi]

Was this just a failure?  Or was there some cause for this? 

[Jeremy airjer W]

My theory is that the windings short out and cause the motor to overheat. That and the fuel filter was almost completely plugged (extremely difficult to blow through) making the motor work that much harder which could also have lead to the short in the windings. It appeared to be the original pump with almost 200k on it if it was. The filter was likely changed at some point as it was not o.e..

 

I should add that this is very common across the "Ford" brands.

[delcecchi]

Thanks.  How big a deal is it to change the fuel filter? I guess they don't have a bypass in the system?

[Macgyver55]

My theory is that the windings short out and cause the motor to overheat. That and the fuel filter was almost completely plugged (extremely difficult to blow through) making the motor work that much harder which could also have lead to the short in the windings.

 Combine that with frequently running low or on empty and its a recipe for a new pump!

[Jeremy airjer W]

Thanks.  How big a deal is it to change the fuel filter? I guess they don't have a bypass in the system?

Depends. Most late model vehicles no longer have a "serviceable" fuel filter. It is located in the fuel tank and is only services with the fuel pump assembly. Most older GM's in Minnesota....... forget about doing it yourself. The lines and fittings are usually so rotted there is no way to get them off with out cutting them off and possible replacing some of the lines and fittings. Dodge has been using the in tank filter on many models for some time. The other models are quick connects and typically are easy to replace. A majority of the Fords are also a quick connect style and fairly easy to replace. Special quick connect tools may be needed for some applications.

 

Overall they are a fairly simple and inexpensive maintenance item that is commonly overlooked.

 

 

[BoxMN]

 Most older GM's in Minnesota....... forget about doing it yourself. The lines and fittings are usually so rotted there is no way to get them off with out cutting them off and possible replacing some of the lines and fittings.

 

 

I have a new filter purchased for my 98 k1500, but haven't done it yet. I did look at it and the little lines looked rusted so had me nervous. Is there some special technique or should Imake sure to have someone who knows how to fix it if it breaks with me, or have them do it? Thanks for the warning! 

190k miles and this is the second or third replacement, but I didn't do the others.

[Jeremy airjer W]

its kind of hard to explain but if I can nut get the fittings to break loose then i cut the filter nut at an angle just until i think I am to the threads. then I take a screw driver and split it apart the rest of the way. you should then be able to unthread the line from the filter. Usually one side or the other will break free. I have found the best combination of wrenches to be a 16mm, a 16mm line wrench, and a 20mm. use the line wrench to break it free and the regular 16mm open end to finish removing. 

 

The lines have an oring (or they should) the lines do not need to be ungodly tight. the oring seals and the tightening just keeps it from coming loose.

[Tom7227]

What was the risk of that pump causing a fire?  I have no clue it is in the tank or what but it looks like a serious problem to have that and fuel close together.

[Jeremy airjer W]

What was the risk of that pump causing a fire?  I have no clue it is in the tank or what but it looks like a serious problem to have that and fuel close together.

about zero to none. I'm sure someone can explain it better but here it goes....

you need 3 things. 

1. An ignition source

2. A fuel source

3. Oxygen

its the lack of oxygen in fuel pump that prevents the fire/explosion.

If you ever watch an electric motor you will see it spark all the time where the brushes meet the commutator. This same thing is happening inside of the fuel pump with gas flowing in and around the brushes and commutator.

[SkunkedAgain]

That's a crazy looking pump.

The only fuel pump that I've ever replaced was on my 2003 F150. It was darn easy to do except for getting a little gas spilled on me because there was still pressure in the line. It was in the driver's side body panel if I remember. Disconnect some hoses, replace, and reconnect hoses. 

[efgh]

I think you replaced the filter, not the pump.

[delcecchi]

pump would have wires for the electricity. 

[Jeremy airjer W]

And it would have been in the fuel tank.....

[SkunkedAgain]

You're saying that I should couple reading comprehension with my forum posts.....sheesh!

 

Noted

Edited November 2, 2015 by SkunkedAgain