Forum | Marketplace | Knowledge Base | | H1 site | H2 site | H3 site
Click Here To Visit Mountain Machine
Click Here To Visit Mountain Machine
Click Here To Visit Adventure Accessories
Click Here To Visit Adventure Accessories
Click here for a listing of all HUMMER Network sponsors

Hummer Knowledge Base

The Hummer Knowledge Base

Fuel Filter Replacement:

>Can anyone tell me how to change the fuel filter?
>The manual says not to attempt unless you know how
>to do it.  Is the concern ruining the thread?  
>Thanks All,

Not too difficult... There are a number of tabs on the housing, one of which is wider than the others. Make sure that the wide tab is in the wide slot (look at the filter, you'll see what I mean!). Make sure it seats all the way down before screwing down the retainer. It is not too difficult, takes about ten minutes:

  1. Drain fuel from filter, using the water drain. Don't forget to open the vent in the top of the filter to bleed in air. Clean around the retaining ring, and top of filter.

  2. I hot wire the pump (makes purging easier), run it for a few seconds to double flush the old filter.

  3. Unscrew the retaining ring, and remove it.

  4. Pull the existing filter straight up and out (as best as you can, it is an odd angle)

  5. Notice that the tabs have one (nearest the front on my truck, I think all are identical) which is wider. Ditto for the filter. It would not hurt to mark the wider opening with a pencil on the outside to help in inserting the new filter.

  6. Insert the new filter in the housing, aligning the large hole with the large tab. Make sure the filter is straight in the housing. Push the filter down into the housing. Not straight may damage the filter's seals.

  7. After seating the filter, screw on the retaining ring hand tight. Don't torque it down with a wrench or whatever: you'll never get it off again.

  8. Purge the filter--again hot wiring the fuel pump is the easiest way to do this. Make sure all air is out, it will gush fuel and air for a few seconds before it is fully purged. That is, don't close it off the second you see fuel coming out: wait till all the air is out.

  9. Write down, on a small tag, the date and mileage of the filter change, and attach the tag to the fuel line going to the filter.

Treat yourself to a nice drink, driving to get it.

The Fram filter is identical to the AM General/Stanadyne unit. I compared each (one from the dealer, $35, one from the discount parts store $15) and except for the date of manufacture, and box, they were identical! Even the numbers and other markings were the same, no question from the same assembly line and plant.

Peter D. Hipson


Changing the fuel filter is actually quite easy, the only difficult part is wiggling the old and new filter into and out of place. I'm assuming you allready know where the fuel filter is located, and if you look at it you can see a black collar around the middle. Simply unscrew this collar (counterclockwise) and lift it off. Pretty easy so far, huh? Now simply lift your old filter out. It might taks a litle effort since there is a slight vacuum to break. Here is probably the hardest part...wiggle your old filter out of the engine compartment without dripping too much diesel over everything. AMG seems to have tucked the fuel filter in a very awkward location, I always snag mine on the throttle cable. If you now look at your new filter(from the paper element side looking toward the top) you will notice a bunch of oval holes along the lower edge. One of these holes will be larger than the rest. Now look at the filter housing bolted on the firewall and you will also notice there is one little "finger" which is larger than the other.. Line up these two parts and drop you new filter into place. It might take a little twisting to get it to seat correctly, but you will know that it is seated when rubber gasket that encircles the cap is sitting flush with the filter bracket. Now take that balck collar you initially took off and replace it. No need for any strap wrenches or the like, a 1/2 turn past snug will suffice.

All that is left is to bleed the air from the system. AMG has there own method explained in the owners manual. An easier was to do this is to simply unplug you fuel pump at the litle black connector. There will be two wires going to the pump, one is black and the other is often grey (I have also seen green) Take two short pieces of scrap wire, about 18 inches long,and strip both ends. Wedge an end of one of the wires into the black wire side of the fuel pump connector. Ground the other end of this wire to some piece of metal on the engine block. Take your other wire and wedge it into the gray (or maybee green) side of the fuel pump plug. Leave the other end of this wire unattached for a minute. Now loosen the black plug and nipple on the top of you new fuel filter a couple of turns. Place a clean rag over the top. You now want to find some easy place to tap into 12 volts + and run your fuel pump. I always use the large CTIS fuse located in front of the CTIS pump. Just pop off the plastic cover and you are all set. Hold the unterminated wire to this until you see fuel flowing out the top of the filter. Once you do, disconnect your wire, and tighten the cap. Once again, no wrenched here, just a snug hand tightening. OK your all done, it will probably take you less time to actually replace your filter than it did to read my long-winded response.


FWIW, here's what I do. '93 and '94 NA. No idea if it is different or more difficult for a new truck I'm sure someone else will chime in if there are differences.

  1. Power wash the area to reduce the chance of dirt getting in the housing when it's open.

  2. Drain the filter housing by opening the drain in the wheel well and the air bleed at the top of the filter. Remember to close the drain when done.

  3. Use an oil filter wrench to remove the plastic retaining ring. They can get tight.

  4. Remove the old filter and clean out the housing. Also clean the retaining ring threads.

  5. Fill the housing 2/3 full with clean diesel. This will reduce the air purge time and make restart easier.

  6. Install the new filter and seal.

  7. Put vaseline on the retaining ring threads to make the ring easier to remove the next time.

  8. Restart the truck. With the above method, I have never had a problem restarting. If there is too much air in the fuel system, you can get air lock that is hard to purge.

  9. When the truck is running, open the air purge valve on top of the filter until the fuel runs out clear of air. Close it and open it a few times to give the air a chance to rise to the top.

  10. Done. The 10-step process to clean living.

I have added a manual switch for my fuel lift pump that makes purging before starting possible. You can jumper 12 volts to the gray wire of the lift pump to run it manually also. However, the above method has always worked well for me even before the manual switch.


One tip comes to mind in addition to what was already said.....

The filter is keyed such that it must be oriented properly when seated in the housing. Make sure you feel the filter "drop" into place before screwing on the retaining ring. Things are a little cramped so could easily be overlooked.

BTW- diesel injection service will sell the stanadyne fuel filter for $10 if you buy 5 or more. This is the best deal I've found yet.


From previously compiled data...

Diesel Fuel Filters:
AM General05742602
DeutschFF749 (Alternate F54719)

Mark L. Gaubatz
1995 Silver Hummer

Back to main page

The Hummer Knowledge Base is a collection of informative posts from the Hummer Network forums and mailing lists, contributed material and links to outside web sites.
The Hummer Network is not responsible for the accuracy of the information contained herein or on outside web sites, nor for any situation arising from the use thereof.
2006-2011 by The Hummer Network. No material from the Hummer Knowledge Base may be reprinted or republished in any form without permission.