Fuel Filter - Diesel

[Pancho Junior Member Find all posts View Profile Close Pancho]

I have a 2005 Prado 120 GXL 3.0 ltr Turbo Diesel, I hope to change the fuel filter out this weekend. Is it easy enough ad are there any pitfalls that I should be aware of?


Cheers - Ian

[Octane94 Member Find all posts View Profile Close Octane94]

yep

1. will make life easier with a vice and a big pair of multigrips
2. make sure surface the new filter screws onto is extremly clean, if it isnt it will come back to bite you, and could possibly ruin your injectors down the track

also make sure to check proper operation of water separator float.

is the kz or d4d?

[Pancho Junior Member Find all posts View Profile Close Pancho]

KZ engine.

[sandman Member Find all posts View Profile Close sandman]

Seriously take your time, its not difficult, its all common sense. You'll need a big pair of multigrips to get the sensor out of the bottom, its not hard at all.

Pete

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

It's pretty easy..
Remove the hose spring clamps and the hoses, disconnect the water sensor wire and remove the nuts holding the filter head to the inner guard. Use a vice to gently (really not even - use the vice jaws as a kind of large adjustable spanner) to clamp the sensor plastic and twist the filter and head assy off it. Drain the fuel into a container and clamp the filter head in the vice and use a filter strap to remove the filter from the head.
Lube the seal on the new filter and install hand tight. Fit the new o ring to the sensor plug and lube it too. Refit the sensor housing just a little more than hand tight.
Refit the head assy and reconnect the cable. Refit the hoses and clamps.
Pump the primer until the plunger goes firm.


Ades

[Dueler120 Senior Member Find all posts View Profile Close Dueler120]

While your at it you may as well install a secondary filter at the same time. Another tip is to fill the filter with clean diesel so your only priming a small amount to get her to crank over.

Cheers,

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

While your at it you may as well install a secondary filter at the same time. Another tip is to fill the filter with clean diesel so your only priming a small amount to get her to crank over.

Cheers,

Sorry Dueler
Good way to introduce contaminants into the fuel system. Not good practice, I know many mechanics that have and will continue to do that.

And don't get me started on adding another filter before the oem one. Waste of money, reducing the flow of cooling fuel through the FIP and possibly shortening it's life. All you're achieving is extending the service interval of the oem filter. Add a water trap/agglomerator (of sufficient flow capabilities) with a water sensor and light/buzzer on the dash.

Ades

[Dueler120 Senior Member Find all posts View Profile Close Dueler120]

Sorry Dueler
Good way to introduce contaminants into the fuel system. Not good practice, I know many mechanics that have and will continue to do that.

And don't get me started on adding another filter before the oem one. Waste of money, reducing the flow of cooling fuel through the FIP and possibly shortening it's life. All you're achieving is extending the service interval of the oem filter. Add a water trap/agglomerator (of sufficient flow capabilities) with a water sensor and light/buzzer on the dash.

Ades

Hi Ades,
I've always used a clean, diesel dedicated 5l jerry can when I've filled my filter during a change. Have had no problems at all with this method. But hey I understand the possibility of contaminates if not careful.

Interesting about your comments on the second filter setup. I was of the understanding that if you match the flow rate you will not have any problems. There are a few senior members on the forum and some of those qualified diesel mechanics that advise its a good thing and have it on their rigs. Anyhow it's intriguing to hear another point on the matter. Can I ask if your in the trade?

Cheers,

[SWR Banned Find all posts View Profile Close SWR]

Gday Pancho

As said above the under bonnet fuel filter is an easy one to change, just take your time and be aware of the fact that it can be a tad tight to un-screw And just for the record the fuel water trap sensor can (Will) be a tight one to remove so don't stress too much if not coming off easy!.. Only tighten it by hand when re-fitting or the %rick to undo tradition of removal in the future will continue!... Lol

I also top the new fuel filter before re-fitting and obviously you must use clean fuel only... As far as fuel contamination goes the whole in the centre of the fuel filter at the top (Where the cartridge screws onto the filter housing) is the supply side too the fuel filter which means if any impurity was to get into the filter then the fuel filter would simply do what it was designed to do and trap it!... That's the whole purpose of the filter!

When re-fitting the new fuel filter (And water-trap sensor) Smear clean diesel onto the O-ring seal with your finger to help the seal to seal tightly without dragging resistance) then pump the purge plunger on top of the fuel filter housing (Black push button) till it gets "rock-solid" and you can pretty much guarantee that the engine will start on the very first turn of the ignition key.

Here below is also the duel fuel tank filter (Diesels only) which i "Highly" advise that you change if it has not been changed within 40-50k.

I wouldn't worry too much (If at all) about its micron filtration (If going none genuine) as it is only a course large particle filter.

Fuel filter dual tanks

Underbody fuel filter

Hope this helps!

Cheers

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

Gday Pancho

I also top the new fuel filter before re-fitting and obviously you must use clean fuel only... As far as fuel contamination goes the whole in the centre of the fuel filter at the top (Where the cartridge screws onto the filter housing) is the supply side too the fuel filter which means if any impurity was to get into the filter then the fuel filter would simply do what it was designed to do and trap it!... That's the whole purpose of the filter!

When re-fitting the new fuel filter (And water-trap sensor) Smear clean diesel onto the O-ring seal with your finger to help the seal to seal tightly without dragging resistance) then pump the purge plunger on top of the fuel filter housing (Black push button) till it gets "rock-solid" and you can pretty much guarantee that the engine will start on the very first turn of the ignition key.

Here below is also the duel fuel tank filter (Diesels only) which i "Highly" advise that you change if it has not been changed within 40-50k.

I wouldn't worry too much (If at all) about its micron filtration (If going none genuine) as it is only a course large particle filter.

Fuel filter dual tanks

Underbody fuel filter

Hope this helps!

Cheers

The OP's prado is a 2005 so has a 1kz-te engine and as such won't have the filter between the tanks.

There's no need to fill the filter prior to fitment, these bleed easily through the FIP and back to tank so there's no mess. And like I mentioned before, why introduce contaminants to the fuel system post filter when there is absolutely no need. If you're filling the filter through the centre can you be certain no fuel has run into the outlet side of the media?

Can I ask if your in the trade?

Diesel mechanic for 30 years with engineering qualifications to boot.
I wish I had a dollar for every fuel filter I have changed over the years.

Cheers

Ades

[SWR Banned Find all posts View Profile Close SWR]

Gday adrian5800

I'm hearing you loud and clear on the possible intro of contaminates to the fuel system but the filter would grab it anyway (Providing that you only fill the fuel through the hole in the middle) and doesn't the fuel have to pass the high pressure pump before entering the common rail and then via the Fuel-Rail-Regulator-dump-valve before heading back to the fuel tank?

My personal reason for filling the fuel filter first is because i think it takes for-ever to purge it with the plunger when the new fuel filter is fitted and the other option is to crank it and it will self purge anyway (As you stated) but this also makes the high-pressure pump suck the fuel through and loads the battery whilst cranking it for what seems forever to me til the fuel eventually gets through!.. Not forgetting that it practically nearly flattens the battery!... or at least half drains it!! Lol

The problem with the forever-cranking is that the current draw from the starter motor (If not purged via the plunger first) is that over time it distorts the plates in the battery and the lining from the led plates falls to the bottom of the battery (Pri glow-plug heat also does this) and this eventually shorts the battery plates. Hence some get two yrs out of a battery and some many more! EG: My battery is 7yrs old and still going! (I have never had to use glow-plug pri-heat) ... You watch now that i have bragged about gettin seven yrs out of my OEM battery to date and still going i bet "Murphy's Law" will now step in and kill my battery this winter!! Lol

Don't get me wrong i am not arguing or disagreeing with you and i am hearing you loud and clear (Is a very valid and true point that you have made) but it's the option that i take as it is much quicker for me in purging the fuel and less stress on the vehicle battery.

I also "assumed" that all 120 series with duel fuel tanks (KZ & KD) had a secondary fuel filter?.... That word "assumption" is a killer don't ya think!! Lol

Cheers

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

Gday adrian5800

I'm hearing you loud and clear on the possible intro of contaminates to the fuel system but the filter would grab it anyway (Providing that you only fill the fuel through the hole in the middle) and doesn't the fuel have to pass the high pressure pump before entering the common rail and then via the Fuel-Rail-Regulator-dump-valve before heading back to the fuel tank?

No the fuel goes to the transfer pump first and will leak off back to tank. It won't go past the high pressure pump/regulator fuel rail. Some engines (isuzu 6hk for example need to primed up to the rail and injectors by pumping by hand and cycling the injectors electrically by the ecu if it has previously run out of fuel).
Back to my comment about ensuring no fuel is added to the outlet side. Guarantee is a strong word.

My personal reason for filling the fuel filter first is because i think it takes for-ever to purge it with the plunger when the new fuel filter is fitted and the other option is to crank it and it will self purge anyway (As you stated) but this also makes the high-pressure pump suck the fuel through and loads the battery whilst cranking it for what seems forever to me til the fuel eventually gets through!.. Not forgetting that it practically nearly flattens the battery!... or at least half drains it!! Lol

Sorry mate I never once suggested cranking to bleed the system.

I also "assumed" that all 120 series with duel fuel tanks (KZ & KD) had a secondary fuel filter?.... That word "assumption" is a killer don't ya think!! Lol

Cheers

Agreed..

Ades

[John Member Find all posts View Profile Close John]

I don't pre-fill filters from the inside (threaded hole), because that is where the filtered fuel is. The flow path on pretty much all filters is over the largest surface area (outside on cylindrical or spin-ons) to inside. I use a syringe to get the fuel down one of the side holes (and past the non-return rubber flap if fitted) to fill the filter. It's slower, but does the job

[campbell Junior Member Find all posts View Profile Close campbell]

It's pretty easy..
Remove the hose spring clamps and the hoses, disconnect the water sensor wire and remove the nuts holding the filter head to the inner guard. Use a vice to gently (really not even - use the vice jaws as a kind of large adjustable spanner) to clamp the sensor plastic and twist the filter and head assy off it. Drain the fuel into a container and clamp the filter head in the vice and use a filter strap to remove the filter from the head.
Lube the seal on the new filter and install hand tight. Fit the new o ring to the sensor plug and lube it too. Refit the sensor housing just a little more than hand tight.
Refit the head assy and reconnect the cable. Refit the hoses and clamps.
Pump the primer until the plunger goes firm.

Ades

As said above but also remove the metal cover that's around the water sensor (loosen 2x8 mm nuts) it's the plastic that you need to grip with the multigrips and screw out. Hold the head assembly in the vice not the plastic. After removing the water sensor the filter is removed with an oil filter strap while the head assembly is in the same position in the vice. I wouldn't be able to do this job without the vise because both were very tight. Hand tighten both. It only takes 1 min of pumping the primer to refill so don't add diesel from another source.