Depressurise fuel sys

[greendisco2]

Hi all , do i have to depressurise the fuel system if i want to change the hose on the expansion tank? tony

[PhilipA]

Huh?
Which expansion tank?
Here I will guess you are referring to a Classic 3.5 V8 with injection but no Carbon canister.

If you are referring to the expansion tank for the fuel in the RH rear guard, then I see no reson to depressurise the fuel system.

Regards Philip A

[greendisco2]

Hi phillip, yeah its a 3.9 in an 84 rrc and yep its the tank inside the right hand guard. I had a petrol smell problem a while back and fixed it with a new petrol cap and tighten up one of the hoses but after those few warm days in melb last week its back so i popped the filler cap and noticed petrol around one of the hoses and a little around the cap, so i thought i would replace the hose and see what difference it makes. tony .ps its a LRA 30 or 40 litre tank as its duel fuel if that makes any difference.

[PhilipA]

I have never seen the setup of the 40 litre Rh guard tank, so I do not know whether we are talking the same thing.

The early petrol cars had a skinny maybe 2 litre tank up high in the RH guard the express purpose of which was to contain any petrol that expanded out of the main tank when it was near full or on a steep angle and it was vented to atmosphere.

So you are on your own. If it is the high pressure hose to the motor that is leaking then you should relieve the pressure , although you can do it by just loosening the clamp and it will be relieved, so wrap a rag around it so you do not get it in your eyes.
Any other hose : no.
Regards Philip A

[Blknight.aus]

to depressurise an injected V8 identify the fuel pump fuse. start the car, pull that fuse and wait for it to stop.

to depressurise a carbied engine either stomp the loud pedal 5-6 times sharply or crack the fuel union on the carby.

[greendisco2]

hey phillip , i do have what you described but the LRA tank is under the expansion tank and the hose was cracked any way replaced hose and seems to have gone for now , but had it dynoed on friday for gas only and its started back firering on the way home , once at the lights and on the freeway :mad: i bought the cheapo tune kit from fleabay the other week , ya get what ya pay for, a trip to the docs i think:(. tony