Replacing Fuel Hoses at Rear of Engine
Alfa Romeo 164 V6
by John Wiltshire

BACKGROUND

From reading the Alfa 164 Digest page, it seems a common problem that fuel
smell gets into the cabin. The flexible hoses on the fuel rails are easy
and quick to replace, however there are two short hoses at the back of the
motor that are not. This is my "home mechanic's guide to changing the
"impossible 164 fuel hoses".
I bought a 1989 V6 164 about seven months ago. I was intermittently
getting a strong fuel smell blown through on the A/C. This was quickly
traced to leaky fuel hoses on the fuel injection rails. I appeared to have
the original Alfa hoses. There were held on by a mixture of the original
single-use crimp-on hose clamps and worm-drive hose clamps. The crimp-on
clamps appeared to be sound and tight, and I tightened the worm-drive
clamps. The fuel smell still persisted - the problem is that the original
hoses go hard with age and no amount of clamping will stop them from
leaking. I replaced all the fuel rail hoses (twice - but more of this
later), and I was still getting an intermittent fuel smell, particularly
first thing after start-up with a cold engine.

THE BACK HOSES

As well as the top fuel hoses that are clearly visible, there are two short
rubber fuel hoses against the firewall on the right-hand side of the car.
These harden and leak like the other hoses, and are often the cause of the
persistent fuel smell after all other hoses are replaced. Because they are
almost impossible to see, the frustration and the smell continues.
To see the hoses, shine a torch or light down where the front of the
firewall meets the inner mudguard. Follow the two metal fuel lines down,
and you will just see them.
There is a note in the 164 Digest Tech Notes that the back hoses are almost
impossible to change with the engine still in the car.
Yes - it is possible to change the back hoses yourself, and yes it is a
tedious job. The up side? Depending on whether your mechanic has done
this job before, you will probably save yourself 2-5 hours labour cost. The real
up side is driving along in a car that has the smell of fresh air instead of fresh
fuel!

A NOTE ON FUEL HOSES AND CLAMPS

When I first had the fuel smell problem, I changed all of the top hoses and
clamps. Within a week, they were leaking worse than ever. I re-tightened
the clamps, but within a few days - same problem. Despite specifying that
the hose was for fuel injection, the auto shop had given me ordinary fuel
hose - this is just not up to the job for high-pressure EFI.
I was surprised how few auto shops carry EFI grade hose, considering the
number of EFI cars on the road. It should be marked "EFI Grade" or "FI
Grade" or something similar.
Make sure you also get the hose clamps that are for high pressure hose -
these look like ordinary worm-drive clamps, but the "loose" end of the
clamp is tucked in rather than on the outside of the clamp. When the hose
is tightened, this covers the inside of the slots to prevent pinching of
the hose. See diagram below.
There have been many comments on the 164 digest about "double clamping" of
hoses using two clamps at each end. This should not be necessary if you
have the right hose and clamps.
Be absolutely sure that you have been sold the right hose. You won't want
to do this job twice!

ON WITH THE JOB

For this job you will need:

- fuel hose as needed - the two back hoses are about 100mm each. I had
about 1500mm of hose and this did all of the fuel hoses.
- hose clamps as needed
- fire extinguisher
- jack and axle stands
- a work light - preferably a smallish one that can be used in tight spaces
- overalls or protective clothing (you are going to lean over the front
brake and get really dirty)
- a long screwdriver to fit hose clamps
- 1/4" drive socket to fit hose clamps with a long extension piece
- some soft iron tie-wire - fine gauge
- rubber grease
- rags to mop up leaking fuel
- patience
- an assistant (only needed for about 15-20 minutes)
- 3 hours depending on your level of mechanical skill and the number of
neighbours that drop in to see why you're working in your Alfa AGAIN...
Despite what the 164 specialist told me (above) I couldn't work out how to
do this job from under the car. Maybe this is possible with a hoist, but
this is a home mechanic's guide - I only have a jack and stands. I'm using
the "through the wheel arch" method. OK - here we go!

1. Start with a cold engine. Depressurise the fuel system by starting the
engine and then removing the fuel pump relay (see owner's manual for your
model) wait until the engine stops - turn off ignition. (I did not need
this step, as my car had sat for 5 days before attempting this job. The
procedure for depressurising fuel system is in the Cardisc CD.) Better
still, depressurise the fuel system the night before, and leave the car to
cool down overnight.

2. Disconnect the battery.

3. Jack up the front of the car, and support it with stands (usual safety
warnings apply - chock rear wheels etc. You will be starting the car while
it is on the stands.)

4. Remove the rubber weather strip on top of the firewall.

5. Remove the metal clamp on the centre front of the firewall that secures
the metal fuel pipe.

6. On the RH side of the firewall (ie Driver's side for RHD models,
passenger side for LHD) there is a plastic clip holding the two metal fuel
lines. Unclip the lines.

7. Remove the RH front wheel.

8. Remove the front and rear plastic gravel shields (there's a split around the
brake pipe fittings).

9. Remove the rear centre plastic cover over the timing belt. This will
give you a little more space to get you hand in. (The smaller your hands,
the better).

10. Position your work light around the thermostat so that it shines back
towards the firewall. Stick you head under the wheel arch, and look
through the gap that you have just opened up. You will see those two
little suckers in all their glory. Now the fun begins.

11. Make sure that the fire extinguisher is close by.

12. There is not a lot to tell about replacing the hoses from here, except
that this is where your patience and persistence will be needed. Reach in
and feel where these things are. You will now realise the difficulty of
getting a hand in there, let alone using a tool there.

13. The first step is to remove the old hoses. The single-use crimp-on
hose clamps need to be removed. If you are not familiar with these
crimp-on clamps, there should be some further up on your injector rails or
the breather hoses on top of the motor for you to have a look at. I didn't
have any success twisting them off with pliers, although if you have some
of those very long ones, you may have more success by being able to grip
the clamp and then the handles of the pliers will be under the wheel arch
rather than behind the motor.

14. After trying several tools and several grazed knuckles, I hit upon the
idea of pulling at the clamps with some wire. I cut a length of tie wire
about 500mm long, and then straightened this by stretching it between two
sets of vice grips. Clip the end off straight. I then fed the wire up
from underneath and fed it through the tiny loop where the hose clamp is
crimped. Feed the wire through until the middle is in the clamp, then bend
it over double. You should have enough wire now to pull back through the
wheel arch.

15. Pull back gently. This should rotate the whole hose so that the crimp
on the clamp that you are working on is at least facing you. Have your
rags and fire extinguisher handy - this step is likely to cause some fuel
to leak.

16. Try a couple of sharp-ish tugs on the wire - this may be enough to
unhook the hose clamp, but remember, don't yank too hard, as you are
tugging on the whole fuel line, and you don't want to dislodge anything
else. Of the four clamps, two of them came off fairly easily with the tug
method. The other two were more tenacious. To get these off, I pulled on
the wire to give some tension, then some poking and prodding was needed
with a long handled screwdriver to dislodge the clamps that last little
bit. This is the bit where you will just have to be persistent, always
being careful not to jab or poke anything hard enough to damage anything
else.

17. By this stage, you should have the clamps off. Make sure that you know
how they will reconnect - it sounds obvious, but I think that it wouldn't
be too hard to cross them over when you reconnect. Now call your
assistant.

18. Ask your assistant to steady the metal fuel lines from up top so that
you can pull the rubber hoses free. Mine came away pretty easily,
obviously due to the hardness of the rubber. Be ready to mop up the
spilled fuel (not too much should come out).

19. Wipe the exposed ends of the metal fuel lines clean.

20. Smear a little rubber grease on the ends of the fuel lines (just a
little). If you have never used rubber grease before, it is water-based
grease that is used for assembling suspension parts etc. I find that it is
absolutely magic stuff for seating the joints between rubber and metal
hoses. If you can't get rubber grease, glycerine will do.

21. Cut two lengths of fuel hose to match the ones that you have removed.
Get your new hose clamps, and screw them down until they are just the right
size to slide over the hose. This step will save a lot of frustration
later, because there is not a lot of space under there for screw turning.

22. Now wash you hands thoroughly. This might seem a silly comment, but
you will be putting tight new rubber hoses on a metal pipe in a very
confined space. You won't have much grip, so you don't want to make
everything greasy.

23. Ask your assistant to steady the metal fuel lines from up top again.
I started by pushing the rubber hoses up from underneath. I got the top
joints together with an alternating combination of me pushing the rubber
hoses up from underneath while assistant steadied the metal lines from
above, and then assistant pushing down from above while I steadied the
rubber hoses below.

24. Now slide the hose clamps over the hose. Position the worm drive
screw on the outside of the fuel lines so that they don't foul each other,
and are reasonably easy to tighten. (see diagram).

25. Now push the bottom metal/plastic fittings up into the rubber hose.
This is achieved in the same way as step 23.

26. Position and tighten the hose clamps. I used a combination here of
the long handled screwdriver and a 1/4" driver socket with two long
extension pieces. Use you right hand to steady the clamp in position, and
turn the screwdriver/ratchet by reaching across you body with your left
hand. Getting these started is tricky, but once the clamps grip the hose,
tightening them the rest of the way is relatively easy.

27. You are now done! Remove the work light from the engine bay.
Re-install the timing belt cover, and reconnect the battery. Start the
engine and check for leaks. You shouldn't have any. Switch off.

28. Make sure that the fuel lines are secure in their lower clip.
Re-install the gravel shields and wheel. Make sure that the fuel lines are
secure in their upper clip on the firewall. Re-install the upper fuel rail
clamp on centre of firewall. Re-install the rubber weather strip.

29. Take the car off the stands. Take it for a test drive. Turn the A/C
on full and enjoy the smell of fresh air coming through.

30. If you feel like I did after the job, you will probably need a hot
bath and a cold beer. Treat yourself to both.

John Wiltshire, April 2000 (edited by AlfaPro).