hi guys,
maybe you already know this, so just ignore it then. but i just found out that apparently, there is more to hoses than meets the eye. been reading a lot of material from aeroquip & moquip(both aeroquip and the uk dealer think automotive's literature) and earl's and apparently, not all hoses are suitable to carry fuel.
in the past, it was ok. most hoses that are meant for oil can be used for fuel but today, gasoline fuels we get are sometimes known as sour fuel in that they contain additives that react with synthetic rubber/rubber. fuel manufacturers add these additives as lubricant for valvetrain due to the removal of lead or as anti knock and cleaning agents.
what these sour fuel causes is swelling when in prolonged contact with rubber and also permeation whereby the fuel permeates through the hose as vapour. this will explain why if you have an external surge tank in the boot with the associated fuel lines, you might get fuel vapour in your car even if the lines are steel braided. of course if you use a solid metal pipe this won't happen.
in essence, you must make sure that your hose is actually designated for use as a fuel hose. usually these hoses contain fluorine. an example would be tfe/ptfe(teflon) lined hoses such as aeroquip's TFE and earl's speed flex hose.
also, do not think that just because a hose appears to be steel braided it is good! there are many imitation hoses out there and you can actually add a stainless steel braid over any normal rubber hose. its just aesthetics. the proper aeroquip and earl's stuff have specifications to meet on maximum pressure and temperature and is much more than just an outer stainless steel braid. likewise their fittings too although they really cost 2 arms and a leg.
sorry for going on, but to recap make sure you use hoses that are actually designated fuel hose even if its just a rubber hose because it will contain flouro liners which make it resistant to fuels. else chao chao.
maybe you already know this, so just ignore it then. but i just found out that apparently, there is more to hoses than meets the eye. been reading a lot of material from aeroquip & moquip(both aeroquip and the uk dealer think automotive's literature) and earl's and apparently, not all hoses are suitable to carry fuel.
in the past, it was ok. most hoses that are meant for oil can be used for fuel but today, gasoline fuels we get are sometimes known as sour fuel in that they contain additives that react with synthetic rubber/rubber. fuel manufacturers add these additives as lubricant for valvetrain due to the removal of lead or as anti knock and cleaning agents.
what these sour fuel causes is swelling when in prolonged contact with rubber and also permeation whereby the fuel permeates through the hose as vapour. this will explain why if you have an external surge tank in the boot with the associated fuel lines, you might get fuel vapour in your car even if the lines are steel braided. of course if you use a solid metal pipe this won't happen.
in essence, you must make sure that your hose is actually designated for use as a fuel hose. usually these hoses contain fluorine. an example would be tfe/ptfe(teflon) lined hoses such as aeroquip's TFE and earl's speed flex hose.
also, do not think that just because a hose appears to be steel braided it is good! there are many imitation hoses out there and you can actually add a stainless steel braid over any normal rubber hose. its just aesthetics. the proper aeroquip and earl's stuff have specifications to meet on maximum pressure and temperature and is much more than just an outer stainless steel braid. likewise their fittings too although they really cost 2 arms and a leg.
sorry for going on, but to recap make sure you use hoses that are actually designated fuel hose even if its just a rubber hose because it will contain flouro liners which make it resistant to fuels. else chao chao.
