fuel pressure release - Toyota Nation Forum : Toyota Car and Truck Forums

NWMO 95 Prizm Lsi · 03-02-2011, 07:11 AM

Good Morning all,

I am going to change the fuel filter this weekend. I see the Haynes calls for stereo removal to get at a valve that will shut off the fuel.

Do most folks use this valve, or do you just ease the fuel filter fitting and let it release the pressure there?

TIA

Chris

Bitter · 03-02-2011, 07:29 AM

I think your haynes manaul is full of it. just unplug the fuel pump electrical and start the engine, when it dies your fuel pressure is gone. disconnect the fuel feed line at the pump to prevent the tank from siphoning itself while you work on the filter. Be prepared for a real fight with the lower fitting on the fuel filter...

speedy25 · 03-02-2011, 12:48 PM

Or leave the back seat on and pull the fuel pump fuse. MUCH simpler.

If that isnt simple enough for you, wrap a rag around a fuel fitting as you loosen the bolt so you dont get sprayed. Its not a lot of fuel but 40# through a small hole can make a fine mist that COULD be explosive, so thats why they tell you to remove pressure first.

I found it was easiest to remove the transmission first to change the fuel filter. Actually I did it while changing a defective transmission and while it was really easy to do with all that stuff out of the way I dont recommend it.

Yes the lower bolt is tough. Get out the longest wrenches you have to get it loose.

-SP

trife96 · 03-02-2011, 10:12 PM

remove stereo??? remove tranny??? shut off valve???

Lmao!!!!...are u guys serious??? Dude, the pressure is not that great, and some fuel will come out but no biggie. Remove the air filter box cover, filter, then three bolts for the bottom housing and intake plenum hose by loosening the clamp, remove the charcoal canister (clamp bolt) and a couple evap lines. This gives you the best access to the fuel filter. Remove the bottom fitting and the top banjo fitting first along with the washers off the banjo fitting. Then remove the filter from the firewall bracket (2 bolts). Reinstall in reverse order. The bottom fitting is a bit of a PITA if it's your first time changin it, but be sure to do it in the exact order I told you and reverse order to install and make sure you have the filter upright cause the bottom and top fitting are different. Install the top fitting with the two washers....reinstall the charcoal canister and filter box....done...piece of cake

NWMO 95 Prizm Lsi · 03-02-2011, 10:57 PM

Thanks guys,

trife96, this is my first time wrenching on a toyota, so I purchased the Haynes manual. Section 4-2 Fuel Pressure Relief Prodecure is recommended before working on any part of the fuel system. Now I understand they can get a little carried away with these safety procedures at times, so that's why I asked the question. Glad it tickled your funny bone.

Thanks for the comments, I will let you know how it goes this weekend. I will be draining and flushing the radiator etc. as well. The gasket for the thermostat is unlike any others I have seen. Do you guys use some Permatex as well, or is it not necessary?

Chris

trife96 · 03-02-2011, 11:03 PM

no prob, but basically, when the ignition is off, the fuel pump is not on, so there is really minimal pressure. Also if u are changing the t/stat, the gasket is really nothing unusual, but make sure you put the t/stat in correctly. It has to go in with the jiggle valve upward facing the upper stud for the housing. Some are marked and the sealant is not necessary...good luck with it man

cipher93 · 03-03-2011, 07:52 PM

The Haynes book does indeed say there is a relay you need to pull behind the center console. Makes no sense to me either, in the procedure, or the fact Toyota would do something so complicated. Pretty sure my mechanic just pulled the fuses/relays for the various fuel system parts before changing the fuel lines.

trife96 · 03-04-2011, 12:01 AM

Or you could jus as easily disconnect ur battery cable lol

speedy25 · 03-05-2011, 07:30 AM

SO how is disconnecting the battery going to release the pressurized fuel ??

-SP

Bitter · 03-05-2011, 08:31 PM

its not, unplug the fuel pump, start the engine and run it till it dies, try to start it again, unconnect the fuel feed line at the pump, get to work.

NWMO 95 Prizm Lsi · 03-05-2011, 10:32 PM

Hey all,

On my 95' Prizm, if you don't want to pull the stereo, etc., you just have to pull the EFI relay under the hood. I cranked for maybe 3-4 seconds and the car wouldn't start. When I cracked the top line into the fuel filter, I didn't even get a tiny squirt.

I didn't mess with disconnecting the fuel line at the pump. I had a little less than half a tank. If I let the line drop, it would start to syphon out. I just hooked in on part of the harness (higher) and it wasn't a problem unless I bumped it knocking it off.

You guys had me worried about that lower nut. I sprayed top and bottom with PB Blaster midweek. I put the car on ramps and had my wife hold the 19mm wrench on the filter up top and got to the bottom line out of the fuel filter with a 14mm. From the bottom side it wasn't bad and broke free without a lot of fight. Kind of a long sucker when you only get short throws on it, but not horrible.

Thanks for all the help.

PS - Haynes said to mount to the new filter to the firewall first and then attach lines. Wile the top is a piece of cake, I had to remove one bolt and loosen the second one quite a little to allow the correct alinement to get the bottom connection started. With it secured to the firewall, the alinement was a mess and it was going to be a royal PITA to get it started. Of course, after getting the bottom started, secure the filter to the firewall before getting serious about tightening the bootom fitting. I had my son hold the filter up top as I finished tightening the bottom.

Chris