In this post I will document a recent filter change. This is the paper filter that goes inside the Davco 234 heater/filter. the insert is a Fleetguard 19761.

I didn’t experience any performance problems, I just noticed on my routine inspection of the filter, that when the car was cold, the oil level in the filter was near the top of the clear plastic dome on the Davco.

Here is a photo of the old filter. Notice that when the engine is cold, the oil level in the filter is near the top. This indicates that the filter is ready for a change. (Note: this is perhaps the greatest advantage of using the Davco filter with the transparent dome.)

STEP 1: The first step is to empty all of the oil from the filter. I removed the top of the filter dome and started the engine. As it runs, the level of oil in the filter falls. Make sure you cut the engine before the oil level drops all the way down. You don’t want the engine to take in any air.STEP 2: The remaining oil in the filter can be drained using the valve at the base of the Davco filter.

I like to collect the oil in a small dish and to make room for that, I remove the windshield washer fluid reservoir. This valve has a threaded hole at the base. I am going to buy a fitting to screw in to that hole and add a 6 inch piece of tubing. This will allow me to drain the oil into a bucket or bowl beneath the vehicle.

STEP 3: I open the valve and drain the remaining oil into the cup.

Notice the particulate matter that was filtered out by the filter. This is only a bit of it. There was actually quite a bit, perhaps two teaspoons full.

STEP 4: The next step is to remove the dome. Unscrew the black sleeve at the base of the dome.

STEP 5: Now the entire dome can be removed.

This filter is black from use. I drove around 3,000 miles on this one.

See the coloration compared to the new filter.

STEP 6: Remove the old filter by lifting it up.

There is quite a bit of debris here on the base of the Davco unit. I removed this dirt with a paper towel. Note: the o-ring is part of the Davco filter unit and is reused.

Replace the o-ring in the groove at the base of the dome.

STEP 7: Put the new filter in place. It just kind of seats itself there.

STEP 8: Replace the clear dome over the filter and then slip the black sleeve over the top of the dome, down to the base and screw it into place.

STEP 9: Fill the filter with oil by pouring it into the opening at the top of the dome.

Screw the top back onto the top of the dome. Now, before starting the car, I pump the fuel primer pump located on top of the engine’s injector pump for a minute or two. My understanding is that this purges air from the fuel line.

Now, you are ready to start the car. After starting it with a new filter, I rev the car for a few minutes. I have been told that if there are some small air bubbles in the line, they will just “blow through” if you are running at 2,000 or so rpms. On this filter change I just let the car idle for 10 minutes and had no problems.

If you have any questions, just drop me an email.

Good luck!