Changing fuel filter: How do you relieve the pressure in the fuel lines?

[Sjackson Lurker Find all posts View Profile Close Sjackson]

My mate and I are changing the fuel filter in my '01 3.4 petrol GXL and can't quite figure out how to relieve the pressure in the lines and filter before we take it out. Has anyone done this before? Some forums suggest things like disconnecting the battery or removing the fuel pump fuse to drain the lines and filter but I can only find a fuse for EFI? If we were to take it out before relieving the pressure how much and what rate would the fuel explode out?

Cheers everyone.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

It only trickles out, If you organise yourself, and do the tank side of the filter first and leave the cap on the other side (so it doesn't flow through the filter) you should be right. Just watch the brass washers, make sure they dont move when you retighten.

[Peterpilot Avid PP Poster! Find all posts View Profile Close Peterpilot]

Open the fuel filler cap before you undo any fittings to relieve any pressure in the fuel tank.

[Torrie 72 Senior Member Find all posts View Profile Close Torrie 72]

To reduce fuel system pressure:
1. With engine running switch to sub fuel tank.
2. Disconnect the white main fuel tank wiring connector, located under the left hand side of the prado forward of the rear wheel.
3. When engine stalls operate starter for 5 seconds.
4. Turn ignition off and reconnect wiring connector.

Make sure you put the filter in facing the right way! OUT stamping to the front of vehicle!

[Sjackson Lurker Find all posts View Profile Close Sjackson]

Thanks everyone, I really appreciate it, I will attempt it again on the weekend and let you know how it went.

On a side note, has anyone managed to get the front diff filler cap off? Pretty tricky for space to get the socket up there not to mention it needed a 10mm allen key. We managed to do the rear diff filler and drain plugs (with a torque wrench mind you) but the front is being stubborn and no room for the torque wrench.

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Thanks everyone, I really appreciate it, I will attempt it again on the weekend and let you know how it went.

On a side note, has anyone managed to get the front diff filler cap off? Pretty tricky for space to get the socket up there not to mention it needed a 10mm allen key. We managed to do the rear diff filler and drain plugs (with a torque wrench mind you) but the front is being stubborn and no room for the torque wrench.

I extended the allen key with a long socket (snug fitt), and socket extension bar. Ensure allen key is properly in; tap it in a bit. A warm diff and cold plug will make it easier. When leavering, slow pressure seems to just damage the plug. I've found it more effective to give ita single, very fast and solid pull.

[Sjackson Lurker Find all posts View Profile Close Sjackson]

So we attempted it again on the weekend with now prevail. We relieved the pressure no problems but couldn't for the life of us get the nut from the tank side of the filter off. It looks like it has been rounded pretty badly over the years. Is there any trick? We can get the engine side nut off no worries and were thinking maybe we could disconnect the engine end and twist the filter while holding the nut tight? anyone had similar experiences? Rounded off and tight bolts have been killing us... Might have to ditch the nut and get a new connector fuel line from the tank. I really don't want to pay a mech 60 - 80 bucks to change the filter just to get one nut undone...

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

So we attempted it again on the weekend with now prevail. We relieved the pressure no problems but couldn't for the life of us get the nut from the tank side of the filter off. It looks like it has been rounded pretty badly over the years. Is there any trick? We can get the engine side nut off no worries and were thinking maybe we could disconnect the engine end and twist the filter while holding the nut tight? anyone had similar experiences? Rounded off and tight bolts have been killing us... Might have to ditch the nut and get a new connector fuel line from the tank. I really don't want to pay a mech 60 - 80 bucks to change the filter just to get one nut undone...

Hmmmmm, Try vice grips, I know it is a bit rough, but it should come loose, What way are you turning it.

[Sjackson Lurker Find all posts View Profile Close Sjackson]

Yeah we were using vice grips. I assume the bolt is on the line going into the filter? therefore we were rotating the nut on the line (not the welded one on the filter itself) anticlockwise to unscrew it out of the filter. Sound about right?

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Yeah we were using vice grips. I assume the bolt is on the line going into the filter? therefore we were rotating the nut on the line (not the welded one on the filter itself) anticlockwise to unscrew it out of the filter. Sound about right?

Sounds like it was well and truely over tightened, I would take it to a mechanic and get them to try, they may have the tools to repair it, if something breaks with the force it will require to get it undone.

[Sjackson Lurker Find all posts View Profile Close Sjackson]

Thanks everyone, I will try again on the weekend. I will price out the fuel line part from toyota in case its cheaper than a mechanics hours labour. Probs could do with a new bolt/nut/thread by now anyway... I'll let you know how it goes.

[Sjackson Lurker Find all posts View Profile Close Sjackson]

A warm diff and cold plug will make it easier.

Hey Glen, just out of interest, how do you cool the plug? ice?...