Hey i got a 78 k5 blazer im trying to smog it passed the emissions test but in california onb older trucks you have to test the gas tank and it failed because it wass leaking vapors how hard would it be to change the rubber hoses on that thing comeing out from the tank and is there any othere seals or gaskets?

 

gas tank isn't that bad to drop. i thought those were carb excempt


*this needs to be combined and moved to full size k5 tech

*please don't double post the same thread in 2 different sections, it takes up bandwidth.

https://blazerforum.com/forum/forum-notice-32/blazerforum-rules-read-follow-28944/

 

It could also just be a faulty gas cap. I had a 78 f150 and it wouldn't pass tn smog for the same reason, turned out it was just a gas cap not holding pressure

 

start simple and do the easy fixes first before you do anything to serious.

x2 on the gas cap

 

x2..... its always easier to fork over a couple dollars first if you aint sure than to jump in and buy an expensive part that don't work

 

hey i bought a 78 blazer from a guy a few days ago he had a smog in hand from 0ctober 6th and it passed well i went down to the smog place and it passed the emissions but on older vehicales they do a gas cap test and it failed because it was leaking vapors i changed 6 rubber fuel line hose they were a little ****ed up but it failed again today ...is there anything like a spray or AN adhesive or sealent to put on the gas tank where the filler hose goes or is it too hard to replace those two filler hoses /??itd really help for some info my first muddin truck project

 

I combined your two treads on this subject. Please do not double post and keep everything in one thread so we can see what you have done.

 

hey its not the gas cap they put a red pressureized cap and pressureize the tank to find where vapor may leak out ive been there 3 times already i replaced all the rubber fuel line hoses the 3 from the tank the filler tube ..pretty much everything rubber others and it still wont pass ....im gonna try to do the same test that they do with some vanilla extract and a airtank to try to see if anything lkeaks out is there any less ghetto way y and do you all know how many lbs. of pressure they use during a test like that?im lost please help if you can i cant even get to the fun **** yet

i guess its called an evap test

 

does anyone know what my next step could be ive replaced all kids of stuff should i pay the smog guy 50 bucks to try and fix it?i dont know if hes ripping me off becausde he keeps redoeing the evap test for free 4 times now

 

idk man, you could replace all your fuel lines tell the cows come home (no pun intended), you need to get it properly diagnosed first. don't know your smog man so i don't know if he's trustworthy. ask around town see if he is trustworthy