Fuel hoses replacement

[mauro12]

Hello everyone, I’m in the process the replace the fuel hoses of my car. I’m talking about the 3 hoses from the tank to the pump. What is the safest way to do the job? Have almost empty tank and disconnect some fuel fuses? Is it a complicated thing to do? Thank you .

[wayne R]

Hi Mauro,, no its not a problem, some times it helps to change one hose at a time,
others here will chime in and help,take a look at my photos you will see that i have a  a small pack,
of rubber hose  caps  available from parts store thay are really handy,for doing jobs like this,
be safe wise as  ,no heat, spark, etc when working with fuel,,you will also see that most probably, use  the correct
canvas cover  fuel hose , im not so fussy about that .,as i had a bad experiance with a Porsche 911 which uses the same
style of hoses, it is harder to  see a leak with that style as it runs down the the hose  on the canvas,so   i  am
just going to use regular   good fuel hose from now on , plus my car is not a show car.      regards.

[mauro12]

So you don’t need to empty the tank before doing the job? My biggest concern is the risk to spill fuel all over the place..

[wayne R]

Mauro, sorry your pm  email box is full, can not send  reply to you.    Wayne. on PM.

[Pawel66]

Mauro, I have recently done what you are doing. The hose caps shown in the previous posts are great and handy. What some people use is also hose clamps - you can buy them for pennies. Or just bend the hose and secure it bent with a tie.

The hose from the tank to the pump, however, the connector on the tank - you have no way of blocking - you can maybe minimize spilling by blocking ventilation, but it will spill - at least I do not know how to prevent it from happening.

So what I did (an amateur):
- drove so that I had very little fuel in the tank
- put the clamp on tank-pump hose
- disconnected this hose on pump side, put its end into a canister, unclamped and drained the tank

You will always spill something, so proper care should be taken like any time you work with fuel (outside, no smoking, no trouble lights, fire extinguisher or balnket at hand etc.).

Once you have the tank drained you may want to flush the tank a bit

Once you are there, I think it is a good practice to install a flow through fuel filter between the tank and the pump. Make sure its connectors diameter match the fuel hoses inner diameter (9mm if I remember correctly, for original hoses). Need to make sure the hose with the filter goes "down the hill" to the pump when secured - pump is gravity fed.

I would have thought it is also a good practice to clean the inner fuel screen in the fuel pump, in its inlet manifold. You may, however, find it difficult to unscrew the manifold (I used air impact gun, 27 or 24mm socket). You would then need a seal ring to put it back.

You may also want to clean the fuel tank screen - may also be difficult to unscrew it, unfortunately.

[Mike Hughes]

I suppose one could always run the car until the fuel level is very low, then carefully jack up the driver's side only (left hand drive car) so that all the remaining fuel flows over to the passenger side of the tank.  Jacking up just the front of the car really high so that all the remaining fuel flows back to the rear of the tank might also do the trick.  Either way might be enough for the remaining fuel level to fall below the tank outlet.

[Pawel66]

This is smart!

i suppose you will still have some fuel in the flower pot (I think this is its purpose), so you may still spill...

[Mike Hughes]

Actually, any fuel in the flower pot will drain slowly out into the tank when tilting a nearly empty tank as suggested.  There are a couple of very small slits at the bottom of the flower pot to allow the fuel level to reach equilibrium with the general level of the tank once the fuel pump shuts off.  These slits also allow fuel to be drawn into the bottom of the flower pot from the surrounding supply in the tank when the pump is first activated.  The fuel pump is really just a circulation pump.  It draws fuel from the tank and sends it to the injection pump.  The injection pump pressurizes the fuel and sends it to the individual injectors.  Any fuel in excess of the needs of the injector pump continues to circulate and returns to the tank. The purpose of the flower pot is to capture this returning fuel and retain a consistent fuel level over the fuel pickup orifice during vehicle operation.  This is intended to prevent the possibility, when the tank level is low, of fuel sloshing around from vehicle motion momentarily exposing the fuel pickup orifice to air.  While both the circulation pump and the injector pump are very efficient at moving liquid they are relatively poor at moving air!

[doitwright]

I just had to do this recently in a W111. Almost empty Tank? Drain the tank with a funnel and some empty milk jugs. You can always put the gas back in the tank when finished. If you have not done so in a while, take out and clean the filter screen at the bottom of the tank (I used the head of a hex head bolt).  You might as well Remove and clean the filter on the fuel pump as well. If you find any debris (I had plenty in my case) in the tanks filter, consider removing and cleaning the tank. All jobs not frequently done, but with an empty tank, are easier and safer.

[Shvegel]

Please don’t blow compressed air into the tank.  Moving air creates static electricity which can result in sparks.  Sparks can result in, “Judging by the position of the bodies.”

[Pawel66]

Thanks for saying that! I did it many times (fuel feed, return line). Important thing to know.