Vacuum in the fuel tank

**yapoy86** · August 5th, 2008 08:24 PM

as per rion illustration.. its not the breather hose but rather the overflow hose.. over flow hose is connected in the tank upper portion going near the fuel filler cap.. its there to flush the air while the tank is being filled with fuel (two matters cannot occupy the same space) ... breather is another thing.. As far as i know.. diesel tanks doesnt have that canister since diesel is not that volatile compared to gasoline.. diesel tanks use breathers with a one way valve where the air can be taken IN but will let fuel fumes pass out very slow just to relieve pressure..

you need to find the breather usually a small hose.. and trace the valve and clean it.. do not put a hole in your cap as this may spill your fuel when the vehicle pass thru bumps and holes

**v6dreamer** · August 6th, 2008 02:04 AM

Originally Posted by rion

no evap emission canister unfortunately, it's a toyota 2.0LT diesel.

Diesel ba!

Kala ko gasolina

.

Pero tama si bambino.......you are a running TIME BOMB.

**Dieseldude** · August 6th, 2008 02:45 AM

Diesel tanks have breathers which can be located anywhere in the tank, including the tank's filler cap. As the fuel pump draws fuel from the tank; the breather allows atmospheric pressure into the tank.

A blocked breather will put the fuel tank on high negative pressure (vacuum), resulting in the following:

low power
hard start condition
an imploded fuel tank.

**rion** · August 6th, 2008 12:15 PM

thanks guys, will try to look deeper. baka nandun lang yang breather sa tank.

wala bang breather filler cap available sa market natin? incase wala akong makita sa ilalim...

medyo takot talaga ako sa drilling a small hole sa cap. it vacuums when running and blows fumes when shaken...

**mbeige** · August 6th, 2008 12:46 PM

If you're a bit worried, the fuel sender unit for the fuel gauge should be located on top of the fuel tank and in theory could be used as a way to bypass the bad vent system, assuming it is a bad vent system. I'm thinking since if it's on top of the fuel tank there's very light risk of fuel spilling. Just don't go with a full tank.

**rion** · August 7th, 2008 03:24 PM

I think I found the real breather, I'm not sure just yet, because I can't see it clearly and reach it.

I do not worry much about fuel spill, but the vapour. I found a vid on youtube about 20ml of meth vapor that could cause this.

20 ml of methanol is injected into a 5 gallon water cooler jug and allowed to turn to vapor

**rion** · August 8th, 2008 04:50 PM

I was able to reach the breather today... and was able to fix it ACCIDENTALLY...

finaly confirmed that it was breather and was able to reach and remove it. tried blow and suck it each end and it was blocked indeed.

so I wash it up with soap and water so I can take a pic and return it to it's place. use the pic when looking for replacement.

before I returned it, I made sure there was no water inside, so I smash it gently to the chair to shake and purge the water out. but when I tried blow and suck it this time, the breather is now working one way route. air only comes in but can't get out. lovely, it is fixed now. hopefuly hindi bumigay.

thanks a lot guys. appreciate the help. * yapoy86: thanks for the tip.