Case Internation 956XL fuel tank venting probelms

[MikeyB]

Hi,

Does anyone know how the fuel tank is vented on a 956XL, every time I take the fuel tank cap off there is a gush of air leaving the tank, enough to blow the cap out of your hands, presumably because it isn't venting properly. I'm not sure whether the 956 is supposed to vent through the cap or by some other means.

Any advice would be gratefully recieved

Thanks
Mike

[Footsfitter]

Hi,

Does anyone know how the fuel tank is vented on a 956XL, every time I take the fuel tank cap off there is a gush of air leaving the tank, enough to blow the cap out of your hands, presumably because it isn't venting properly. I'm not sure whether the 956 is supposed to vent through the cap or by some other means.

Any advice would be gratefully recieved

Thanks
Mike

Unfamiliar with the tractor model but has it a turbo? and has it a rotary cav pump? a common fault that can pressurise fuel tanks came where engines had the cav rotary fuel pump with a boost diaphragm operated by a signal pipe to the inlet manifold- if the diaphragm split it was possible for the air from the turbo/manifold to get through the split diaphragm and into the fuel system leading to pressurisation of the fuel tank.

see-

http://farmingforum.co.uk/forums/sho...l=1#post238091

[ACE]

Hi,

Does anyone know how the fuel tank is vented on a 956XL, every time I take the fuel tank cap off there is a gush of air leaving the tank, enough to blow the cap out of your hands, presumably because it isn't venting properly. I'm not sure whether the 956 is supposed to vent through the cap or by some other means.

Any advice would be gratefully recieved

Thanks
Mike

Have a feeling these have a bosch pump with a boost diaphragm on the top.

If so care needs to be taken when replacing as its easy to put them back in wrong then loose all the boost.