CK35H Fuel tank collapsed

[zarashep]

The plastic fuel tank on my Kioti CK35 HST has collapsed, The tank top has become concave and it holds about half of the fuel it used to. The good news is that it does not leak. Has anyone heard of this? Can I pressurize it to pop it back to its original shape, or is a new tank in order?

 

[TBDonnelly]

My CK30 HST has a vented fuel cap. Is the fuel cap original? Check the bottom side of the fuel cap to see if it's become blocked. Does the tractor run normally or does it act like it's starving for fuel?

Don

 

[Dmace]

Plastic fuel tank? When did this start?

My 2006 CK20HST has a metal tank.

 

[zarashep]

The tractor runs fine. I lost the original cap but replaced it with a Kioti cap that I bought from the Kioti dealer.

 

[zarashep]

It started about a week ago and it got much worse today. It looks like a grey ABS-type material but I will scratch it with a knife tomorrow to be sure.

 

[whiskywizard]

Any un-vented tank can be collapsed easily by even a small pump. Regardless whether the tank is plastic or steel, a fuel lift pump or an injection pump is quite capable of collapsing it if it's not vented. I'll guess the new cap is not properly vented.

Re-expanding by inflating is not so easy and potentially very unsafe. You may have to replace it, or live with reduced fuel capacity.

 

[VictorW]

Plastic fuel tank? When did this start?

My 2006 CK20HST has a metal tank.

My 2004 CK30hst has a gray plastic tank just in front of the firewall and behind the engine. It's never collapsed. The plastic is pretty heavy/thick. If you lost about half of the capacity, (4gallons), it must be really crushed down. I'd imagine the plastic wouldn't like coming back to it's original shape without cracking somewhere. I also think your cap isn't venting.

 

[MotorSeven]

My 2004 CK30hst has a gray plastic tank just in front of the firewall and behind the engine. It's never collapsed. The plastic is pretty heavy/thick. If you lost about half of the capacity, (4gallons), it must be really crushed down. I'd imagine the plastic wouldn't like coming back to it's original shape without cracking somewhere. I also think your cap isn't venting.

Yep, not venting. My '08 DK40 has a plastic tank.

 

[Willl]

Drain it.
Clean it.
Block off exit/input lines.
Gently apply positive pressure.
Fix vent in cap.
Reconnect lines.
Refill tank.

 

[TBDonnelly]

Click on the link for a picture of the vented fuel cap off my CK30:

http://www.tractorbynet.com/forums/...431-art-delivery-fueld-questions-img_1225.jpg

Don

 

[zarashep]

I lost my original cap that looked like the one you showed me. The replacement tank the dealer sold me looks different - and evidently is not venting. I even phoned back to ask if there should be a hissing sound whenever I removed the cap - a sound I didn't recall from the first cap. I was told (incorrectly, I guess) that it was normal. Thanks for the photo.

 

[zarashep]

I was hoping I could re-inflate it. I worried that the pressure could blow the cap off. Do you know what PSI I should apply? Would you remove the tank first?

 

[lilranch2001]

I was hoping I could re-inflate it. I worried that the pressure could blow the cap off. Do you know what PSI I should apply? Would you remove the tank first?

I dont think I would put any more than 3-5 psi in it

 

[zarashep]

Thanks WhiskeyWizard. What dangers are there in re-inflating? If I replace the tank, I will need help in how to do it. The shop manual does not give much of a clue.

 

[blueriver]

How about filling it as full as you can and park it on the south side of a building ... the sun should expand things back into shape.

My Montana tank collapsed because the cap vent was plugged and it came back to shape this way ... may or may not work for you.

 

[MotorSeven]

I like BlueR's idea, but since it's wintertime might or might not work depending on Zara's location.
Plastic gets brittle in cold, so before trying to "inflate" it I would get it inside a heated shop and warm it up. The warmer the better and the easier it will be to get back into shape. I'm thinking pointing a kero salamander at the tractor for a couple of hrs until it's warm to the touch. If you fill to the brim when cold, then warm it up remember you will spill some fuel when you open the cap so have a catch pan underneath(oh and you might want to turn that salamander off).

 

[blueriver]

I like BlueR's idea, but since it's wintertime might or might not work depending on Zara's location.
Plastic gets brittle in cold, so before trying to "inflate" it I would get it inside a heated shop and warm it up. The warmer the better and the easier it will be to get back into shape. I'm thinking pointing a kero salamander at the tractor for a couple of hrs until it's warm to the touch. If you fill to the brim when cold, then warm it up remember you will spill some fuel when you open the cap so have a catch pan underneath(oh and you might want to turn that salamander off).

Yes I don't know his location either ... the salamander is a good idea. I know when mine happened it was summer time so thats why I threw in "South" side forthis time of year.

Next examin the cap ... for some reason its not breathing.

 

[VictorW]

Does anyone know the price of a new tank? If it's expensive, I'd go through the extra work of removing the old tank to make sure you could get it warm enough before blowing it back into shape. This would also allow you to warm the collapsed areas more so hopefully these would respond to the air pressure. If a new tank is reasonably cheap, then giving it a try in the tractor would save time if it works.

In the meantime, unless you get a new cap, loosen your fuel cap a little if running the tractor. That may save you having to spend @$60 on a new fuel pump. And the dealer that said the hissing was normal when opening the cap, :confused2: maybe he was thinking of the sealed system in todays road vehicles.

 

[mguitas]

I never heard of a fuel tank collapsing. Very odd.

 

[ritcheyvs]

Does anyone know the price of a new tank? If it's expensive, I'd go through the extra work of removing the old tank to make sure you could get it warm enough before blowing it back into shape. This would also allow you to warm the collapsed areas more so hopefully these would respond to the air pressure. If a new tank is reasonably cheap, then giving it a try in the tractor would save time if it works.

In the meantime, unless you get a new cap, loosen your fuel cap a little if running the tractor. That may save you having to spend @$60 on a new fuel pump. And the dealer that said the hissing was normal when opening the cap, :confused2: maybe he was thinking of the sealed system in todays road vehicles.

According to these guys:
OEM Parts

or OEM Parts it's about $200. But shipping and work to remove and replace could be more substantial. An unvented fuel system absolutely will collapse the tank. I'd say you have a bone to pick with the guy that sold you the unvented cap.