Changing the fuel filters on a 348

The 348 uses two fuel filters, one for each bank of cylinders. The arrow in the first picture shows the location of the filter for the left (driver's side) bank. The other filter is in a similar location on the right side, just in front of the exhaust manifold.

The filter is a Bosch part (# 0 450 905 601) and should be available for considerably less money than your Ferrari dealer would charge.

Before starting the removal, make certain that your ignition switch is off and that no one will be able to turn the key while you are working. Hide the key. Do not smoke. Do not have any sources of heat or spark near the area, including portable workshop trouble lights. It's best to do this operation in a well ventilated area, as you will be releasing a small quantity of gasoline when the fittings are removed. And of course, don't do this job on a hot engine!

When you look down in the engine bay, it appears that the filters are in extremely tight locations, and that it would be difficult to get your wrenches onto the fittings to remove them. The situation is greatly improved by removing the nut and bolt for the attachment clamp (53 and 54 on the chart) with a 10mm wrench so that the filters can now be moved into an easier position while still attached to their flexible hoses.

The new filter generally comes "bare", without the upper and lower unions (56 and 58 in the chart). You want to remove the filters while these unions are still attached to them, as it is easier and safer to swap the unions on the workbench. Using a pair of 17mm open-end wrenches, grip the end fitting on the flexible hose (61 or 62) with one wrench and the union (56 or 58) with the other wrench, and unscrew the hose from the union, keeping the wrenches as straight as possible on the flats of the fittings. Some gasoline will be released when the fittings break free, so have a drip pan under the engine to catch the fuel.

Once both flexible hoses are disconnected, remove the filter to the bench and remove the unions from the filter, keeping track of which is the upper and which is the lower. The filter is marked with an arrow to show the direction of flow (arrow should be pointed UP). When re-installing the unions onto the new filter, new crush washers should be used of the correct size. You want the unions to be screwed on TIGHT.

Reassembly is the reverse of disassembly. Give the hoses a good visual inspection for any signs of wear or stress cracks in the metal fittings. Remember, the fuel system operates under pressure and the fittings must be tight. You want the hoses aligned naturally to put the minimum amount of stress onto them. Avoid tight bends.

Once the new filters have been attached to the hoses, but before the filters have been reinstalled into the clamps, turn the key to the "on" position to activate the fuel pumps, and check carefully for leaks. If everything looks OK, start the engine and let it run for a minute or so, then recheck for leaks. You don't want to wait until the filters are clamped down where you can't easily reach them before doing your leak checks.

When you're sure there are no leaks, put the filters back into the clamps and tighten down the securing bolt and nut. Then let the engine run at idle for a few more minutes and recheck. Remember, these filters are only a few inches from the exhaust manifolds, and if the fittings leak, your car could catch fire almost instantly.

This job can be performed with simple hand tools, but it MUST be performed correctly! If you are not confident of your mechanical skills, leave this job to an experienced professional!

Other FChatters are most welcome to offer comments and additional suggestions.
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Be very careful when retightening the fuel hoses to the fuel filters. DO NOT OVER TIGHT THIS WILL RESULT IN THE HOSE CRACKING AND EVENTUALLY SPRAYING FUEL OVER YOUR MANIFOLD AND COULD RESULT IN A FIRE. !!!

 

Great write-up!

Did Ferrari move these two fuel filters further back towards the firewall in later models? I ask because mine appear to be further back than the one in your picture above.

 

TMoblie, wow Miltonian really gave a great discription on the fuel filter, I have a 348ts and read the info on this site daily. Great site, learned alot. I have some pictures of my a/c printed circuit but cant seem to get them on this site.
NAAG123

 

As usual, a great description by Miltonian.
Just one thing to add - access is easier through the wheel wells. Lift the car, remove the wheels and inner covers and the filters are right there. Picture attached.
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question.

why did they think it appropriate to place the fuel filter a couple
of inches away from the manifold ?

 

It's tight but there's actually more room there than it appears. The angle makes it look like the manifold is almost touching the filter but it isn't

 

You can order the filters here: www.drivewire.com

 

Jeff's never changed his before, he stayed at a Holiday Inn Express last night...

 

Cut & paste the Bosch part #0 450 905 601 where it says "Enter part Number" at the top of page.

Filters=$12.96/filter and received mine in 3 days.

 

Ferrari oem part cost 39.14Euros pce...

 

Good info!

What type of washers are parts 57/59 above? Are they solid copper or the type that crushes on assembly? (like the one used on brake line fittings etc)

Cheers,
Chris.

 

Thanks Steve!