NewHilux.net

Hopefully there's the problem. Was it the cap itself or the breather?

Addit - Will relocate these posts to appropriate topic
For tub style, the fuel filler breather only works when filling up. It doesn't breathe when the cap is on.
What was your filler neck breather blocked with? Highly likely the fuel pickup will be blocked too if the filler was blocked

The tank breather needs to let air in when fuel is being consumed or it will collapse like the image that TOYZX posted in the link above.

The tank breather line lies on top of the tank in a recess channel at the end of about 1 foot of fuel hose.
The tank end can be seen from the left wheel arch. You will need to get access under the car between the drive shaft. Feel for the breather valve on top of the tank just above the heat shield. Once located you can pull it up by hand as it is only press fitted to the tank with a square locating plug (see addit below).



I will find some images and post here later

Old Images added:
This gives you an idea where it is.
Easy with the tub/tray off but still reachable when on.

Tub on. The terminating end sits out of the recess on top of the tank under the rear of the cab.


Tub off. Breather line pulled backward. Toyed with the idea of attaching breather elevated to the back of he cab.


Front of vehicle is on the right side (back of cab is white - right corner of image)
The breather line goes to the front under the cab - tank recess can be seen in the right lower corner under the cab
You can see the square locator is part of the valve cover. Press the hose spring clip together and pull the entire valve assembly off. Block hose end while inspecting/cleaning the valve. Carefully remove valve cover. Note direction of valve for reassembly and blow out in the direction of exit from tank.



Addit - memory is clearly fuzzy after 5+ years
Had a look under my partners car and inspected valve.
The valve cover also has a small round ball - this clips into the top of the tank.
I pulled a friends breather valve a few years ago from a Prado on the CSR that was blocked. The square locator is used for the prado - same valve.

You will need to pull the hose clip down about 35mm then initially lever the valve off the breather hose with a flat head screw driver to get it moving.


Tricky to get the valve out - 2 one-way retainers hold the valve in. Push the opposite sides of the valve cover in with fingers and pull vlave out. You may need to use a small flat head screwdriver to push the retainers in with a 3rd hand

A bit of debris fell out from the end of the cover.

The valve will only go in one way but marked the distal end as a visual reminder to blow out that direction
Squirted a bit of MAF cleaner into the valve. Wasnt blocked but some crud came out.
Blowing out by mouth was enough but may not be if blocked.


Push valve back into cover once clean and dry
A little tricky to locate the little plug hole on top of the tank to push the valve cover ball back into but use fingers to find the hole and direct the ball into it.
About 15 minutes all up - most of this time was trying to get valve apart without destroying it.
A bit of preventative maintenance well worth the 15 minutes

I cant seem to locate the breather in your picture maybe my model if different. I might have to drop the tank to see it. This is the other breather on the fuel cap i found blocked. https://www.bing.com/videos/search?q=fu ... M%3DHDRSC3

The cap it self i attached a video i found on cleaning it.

Thanks for posting the video link.
Interesting he still had some suction noise after this fix. Indicates that there is still a pressure equalisation problem. That cap may work to relieve excess positive tank pressure, not so well with negative pressure?
Looked at a cap from a tray back - full of red dust and diesel but the tank breather valve is doing its job.

Petrol hilux tank has an evaporation tube running the entire length of the tank + no valve.
Would be strange to have no breather on a D4D tank


If you have a tray its easy to see the tank entry of the breather.
Side view - filler neck breather in foreground entering blue spigot. Black valve breather line entry in the background


Valve breather line in middle of image


ebay listing image of dropped tank:

Thanks for that deadly beast i found it and it seemed to be all clear i also blew on pipe it seemed clear also. Great pictures

That leaves the question, why did the Hilux run out of fuel?

Hi DB, I just tried to post into this thread and got a forbidden notice, dunno why so I'll send you what I tried to post:
I was impressed by the pictures you posted but it got me thinking, if that hose/valve allows air into the tank to equalise pressure, wouldn't it be a serious danger if you take your Hilux into deep water? I would expect that serious off-road hiluxes should consider extending the hose much higher to prevent water ingress into the tank?

Geoffcaso wrote:Thanks for that deadly beast i found it and it seemed to be all clear i also blew on pipe it seemed clear also. Great pictures

No problem, thats good news.
The not so good news: to run out of fuel with 30L remaining, leaves the pickup filter/strainer that must be clogged up.
My old '07 tank strainer was nearly blocked but caught it before it starved of fuel

Cleaning fuel pick up filter

Gipsy wrote:Hi DB, I just tried to post into this thread and got a forbidden notice, dunno why so I'll send you what I tried to post:
I was impressed by the pictures you posted but it got me thinking, if that hose/valve allows air into the tank to equalise pressure, wouldn't it be a serious danger if you take your Hilux into deep water? I would expect that serious off-road hiluxes should consider extending the hose much higher to prevent water ingress into the tank?

Yep - it doesnt sit that high up however, the valve is semi-one-way. Is easy to blow outward but there is resistance when trying to blow in the direction toward the tank. Many have gone through water that would easily cover the tank with no problems... unless ingress thru the air intake.

I extended my breather into the engine bay to prevent dust clogging it up
Will be dropping my tank in the next year or two to clean the pickup

Yes i agree it was easier to blow one way so and there is resistance the other way. So can you tell me something is there an access plate to get to the fuel pick up inside the cab or do i need to drop tank?

Gotta drop the tank
Clean with kerosene, change your engine bay fuel filter, treat next couple tanks with a diesel bug killer
If you cant drop the tank this weekend start the diesel bug additive now

Diesel Bug

Suggestion: maybe try removing or loosening the fuel cap and see if it is a pressure issue by driving it. Otherwise, if the engine runs out of fuel at 30 litres, removing the fuel cap should then equalise pressure. Otherwise it's a fuel pickup issue and tank must come out.
Also, is this a new issue or has it done this for a while? If it's a new issue what has changed? Maybe the previous owner had this issue when the vehicle was sold? Is the vehicle a recent purchase?
Just a few questions to help pinpoint the problem.

Hi Deadlybeast i thought i would give an update i didnt run out of fuel this time tank is empty. All i did was clean the air vent on the fuel cap and put some injector cleaner in the tank...

Good outcome mate. Thanks for posting
Interesting - I imagine that both the breather and the cap must have been blocked otherwise one of them would have allowed the tank to equalise. That tank is likely due for a clean out if not regularly treated

Hi I have not run out of fuel this time. The only thing i did was clean vent on fuel cap and put injector cleaner in the tank....

So presumably the cap is also a one-way vent?

You would hope its only one way - its pretty good at collecting red dirt
Even if it was blocked I cant see an reason why the tank breather wouldn't work unless it was also blocked
Threads merged