Why won't my Optimus Hiker pressure up?

[twisted firestarter]

I had my Hiker up for sale and thought I'd test it since it hasn't been used for a few months but I can't get it to pressure up. Last time I used it everything worked fine and it has (fresh) fuel in the tank. It doesn't matter how many times the plunger is pumped, it's just not getting any pressure build up. It has the same burner as the Optimus Nova.

Any ideas

 

[johnboy]

It's this model of Hiker?

It could be an issue with the non return valve (NRV).

This valve allow air into the tank but stops it from escaping back out the pump tube.

Unscrew the pump plunger retaining nut and have a look down the pump tube you can see the NRV.

HTH

John

 

[Andy BB]

Check the washer on the end of the pump - if that's failed nothing will pressurise.

 

[demographic]

It's this model of Hiker?

It could be an issue with the non return valve (NRV).

This valve allow air into the tank but stops it from escaping back out the pump tube.

Unscrew the pump plunger retaining nut and have a look down the pump tube you can see the NRV.

HTH

John

Whilst on the subject of NRVs...

I take it that there's a special tool to get to them as I heard that you shouldn't just use a screwdriver, so what does the special tool look like?

Anyone?

 

[filcon]

Try taken the plunger washer off soak it then reverse it,the washers shrink through time also check relief nut.

phil

 

[twisted firestarter]

Thank you I'll try those tips and let you know how it goes

 

[johnboy]

Whilst on the subject of NRVs...

I take it that there's a special tool to get to them as I heard that you shouldn't just use a screwdriver, so what does the special tool look like?

Anyone?

Depends on the type of NRV fitted to the stove....

A simple tool can look like this...

On the older Optimus Hikers you could use the handwheel that adjusts the flame to remove the NRV... I'm not sure if that is the case with this version...

Anyway remove the pump rod assembly and have a look at the pump washer as the others have said. it will either be a leather cup washer type arrangement or it will be a metal carrier with an 'O' ring on it. Optimus on the last proper Hikers used the O ring arrangement.

What they use on these Hiker / Nova hybrids I have no idea.

If it's a leather cup make sure its supple and lubricated ( olive oil works well). If it's an O ring is it cracked or split or missing?

Asuming the stove is capable of making pressure and the pump assembly is in good condition I'd then look at the NRV....

HTH


John

 

[demographic]

Depends on the type of NRV fitted to the stove....

A simple tool can look like this...

On the older Optimus Hikers you could use the handwheel that adjusts the flame to remove the NRV... I'm not sure if that is the case with this version...

Anyway remove the pump rod assembly and have a look at the pump washer as the others have said. it will either be a leather cup washer type arrangement or it will be a metal carrier with an 'O' ring on it. Optimus on the last proper Hikers used the O ring arrangement.

What they use on these Hiker / Nova hybrids I have no idea.

If it's a leather cup make sure its supple and lubricated ( olive oil works well). If it's an O ring is it cracked or split or missing?

Asuming the stove is capable of making pressure and the pump assembly is in good condition I'd then look at the NRV....

HTH


John

Grand stuff, thanks.

 

[twisted firestarter]

OK I took out the pump rod assembly and looked down the tube, the NRV is the slotted same as the one on the right of Johnboys photo. While the rod assembly was out I noticed the cup/washer was dry so I dipped it into the fuel filler hole until it was soaked and then reassembled everything. To my relief it pressured up with no problem so I made a brew just to make sure, it was a simple as that in the end but thanks all for the great advice

 

[johnboy]

Nice one...

You'll need to use some form of oil on the pump washer... The fuel will evaporate and the washer will dry out again..

Olive oil works well and most folk have it.. let the pump leather soak in it for about a day that should see you right...

HTH

John

 

[twisted firestarter]

You'll need to use some form of oil on the pump washer... The fuel will evaporate and the washer will dry out again..

Olive oil works well and most folk have it.. let the pump leather soak in it for about a day that should see you right...