Fuel tank check valve

[BigSkyBrad]

Walking past our truck today, I noticed to my horror that the fuel tank is stoved in, and subsequently the fuel pump assy is mangled! Weirdly, every section except the two ends have some degree of inward deformation.

I figure it is one of two things...
a) someone has backed into it
b) it has vacuum imploded

I have found an alloy replacement tank, and OEM Bosch fuel pump, but if it was a vacuum issue, I'll need to replace the breather check valve.

Does anyone know the part number of the valve, MK_________ ? Or would any simple two-way check valve do? (far cheaper option)

Cheers in advance

 

[SkiFreak]

You're not having a good run, are ya mate?

Does anyone know the part number of the valve, MK_________ ? Or would any simple two-way check valve do? (far cheaper option)

It's just a breather, so any other check valve should be able to do the job.
What quite a few people do is to run a hose from the breather hole (1/4" NTP thread) up to a higher location, which increases your fording capacity. Any diff breather type setup would work if you do that.
If you insist on simply replacing the OEM check valve, the part number is MB390572.

From the image it does not look like anything has hit the tank, as there are no obvious marks.
Are you sure that won't just buff out???

 

[ThundahBeagle]

Corner of rear bumper backed into you, is what I think. Straps seem to have held amazingly well, though. Good luck. Let us know what you do

 

[Pntyrmvr]

Fill it full of water and drop it in the chest freezer. That's what we used to do with rare beer cans we were collecting. Might take a few cycles.

 

[Alloy]

Fill it full of water and drop it in the chest freezer. That's what we used to do with rare beer cans we were collecting. Might take a few cycles.

a 1/4 to 1/2PSI is faster

 

[Pntyrmvr]

Less mess too.

 

[BigSkyBrad]

From the image it does not look like anything has hit the tank, as there are no obvious marks.

That's what I thought. If it's a vacuum issue, the fuel pump must have amazing strength to keep sucking.

I've found a check valve that will do the job - a motorsport one that flows both ways til the vehicle goes past 90deg angle, basically a stainless ball bearing blocks the outlet so that there's no spill when the vehicle topples over.

 

[Alloy]

That's what I thought. If it's a vacuum issue, the fuel pump must have amazing strength to keep sucking.

I've found a check valve that will do the job - a motorsport one that flows both ways til the vehicle goes past 90deg angle, basically a stainless ball bearing blocks the outlet so that there's no spill when the vehicle topples over.

Doesn't take much to collapse a tank

 

[SkiFreak]

Doesn't take much to collapse a tank

Yeah... but the truck was not surrounded by children (as far as I know)

 

[BigSkyBrad]

The tank was definitely subjected to a vacuum implosion. Inspecting the breather valve showed it working (just), so I suspect there has been moisture in the valve which froze.




I've installed a new alloy one. I found a custom tank builder, who luckily builds a number of tanks for certain vehicles as spec stock - and he had a Fuso one on the shelf. It would have been nice to commission a larger one (which would also have meant new hangers), but we were needing the truck back on the road asap. It's a shame it's only made from 2.5mm, so I'll glue some rubber sheet to the front end to protect it from stones etc.

 

[SkiFreak]

Shiny!