Fuel leak - help / assitance required
Discussion
Just back from a weeks holiday and really looking forward to taking the Griff out this morning.
Drive out of the garage and go to shut doors and notice a trail of petrol on the floor. Switch engine off and look underneath to see a large amount of fuel dripping from around the bell housing and clutch slave cylinder. Look under bonnet and notice that the rear offside fuel pipe (the one that comes from the end of the fuel injector metal pipe and runs down the back of the engine) is damp with petrol, but not to the extent that petrol dripping below would suggest.
After a while when it has stopped and the fuel hose has dried I re-primed the fuel pump and started the engine, the drips below started again, but at a lesser rate, and again the pipe behind the block only looked damp. Switched the engine off and after much deliberation I took a risk, fired up the car a drove it back into the garage.
On further examination I can just see the other end of the pipe which is clipped on to a metal pipe which sits above the bell housing, its difficult to see and looks bl__dy impossible to get at without taking most of the ancillaries and rocker covers off and then I'm still not sure I can get to it to change the pipe.
After the football I had another look and started the car once again, this time there is no sign or smell of petrol, either below or above the engine.
Having looked through the bible I think the pipe in question is the fuel return to the tank.
If this is the case I assume that it normally returns the fuel at low pressure and wonder if after being left for a week or so in the current heat the pressure built up in the fuel tank causing the fuel to leak out when the car was first started. I have since checked the fuel filler cap and did not notice any build up of pressure.
I have inspected the hose as closely as I can and it feels (as I can't see at this point) as if there may be a small hole where it has been rubbing on the corner of the block.
Questions:
1) Am I right in the identification and purpose of the pipe / are my assumptions right about it normally being at low pressure?
2) Is it possible its been a problem for a while?
3) How do you get to the bottom end / what needs to be removed to change the pipe
I feel this would be better resolved by a garage, so I wonder if the leak appears to have stopped if it would be safe to drive the car to my local indy, about 15 miles away?
The car is a 96 500
Any advice or guidance would be much appreciated.
Many thanks
RAS
Drive out of the garage and go to shut doors and notice a trail of petrol on the floor. Switch engine off and look underneath to see a large amount of fuel dripping from around the bell housing and clutch slave cylinder. Look under bonnet and notice that the rear offside fuel pipe (the one that comes from the end of the fuel injector metal pipe and runs down the back of the engine) is damp with petrol, but not to the extent that petrol dripping below would suggest.
After a while when it has stopped and the fuel hose has dried I re-primed the fuel pump and started the engine, the drips below started again, but at a lesser rate, and again the pipe behind the block only looked damp. Switched the engine off and after much deliberation I took a risk, fired up the car a drove it back into the garage.
On further examination I can just see the other end of the pipe which is clipped on to a metal pipe which sits above the bell housing, its difficult to see and looks bl__dy impossible to get at without taking most of the ancillaries and rocker covers off and then I'm still not sure I can get to it to change the pipe.
After the football I had another look and started the car once again, this time there is no sign or smell of petrol, either below or above the engine.
Having looked through the bible I think the pipe in question is the fuel return to the tank.
If this is the case I assume that it normally returns the fuel at low pressure and wonder if after being left for a week or so in the current heat the pressure built up in the fuel tank causing the fuel to leak out when the car was first started. I have since checked the fuel filler cap and did not notice any build up of pressure.
I have inspected the hose as closely as I can and it feels (as I can't see at this point) as if there may be a small hole where it has been rubbing on the corner of the block.
Questions:
1) Am I right in the identification and purpose of the pipe / are my assumptions right about it normally being at low pressure?
2) Is it possible its been a problem for a while?
3) How do you get to the bottom end / what needs to be removed to change the pipe
I feel this would be better resolved by a garage, so I wonder if the leak appears to have stopped if it would be safe to drive the car to my local indy, about 15 miles away?
The car is a 96 500
Any advice or guidance would be much appreciated.
Many thanks
RAS
Edited by RAS on Sunday 27th June 19:12
do Not drive the car until you have this fixed, petrol, hot exhaust, car on fire in seconds, kaboom!
go to a motor factors, get some fuel injection hose, from memory its 8mm bore, but someone may confirm this later, and a couple of new hose clips.
to gain access you need to remove the plenum, you should then be able to reach down to remove the rubber hose from the copper fuel line, and replace it with he new hose, not easy but it is doable.
this is a common problem if these hoses are not checked, once fitted make sure that there is nothing that the hose can rub against when the engine is running.
go to a motor factors, get some fuel injection hose, from memory its 8mm bore, but someone may confirm this later, and a couple of new hose clips.
to gain access you need to remove the plenum, you should then be able to reach down to remove the rubber hose from the copper fuel line, and replace it with he new hose, not easy but it is doable.
this is a common problem if these hoses are not checked, once fitted make sure that there is nothing that the hose can rub against when the engine is running.
Edited by clive f on Sunday 27th June 19:43
Clive,
Thanks for the quick response.
Can't say that I was happy with the thought of driving it although the leak appears to have stopped, which I find a bit odd.
I assume its just a case of undoing the 6 hex screws and lifting / drawing the plenum forward, disconnecting the minimum number of ancillaries until there is enough room to get to the pipe.
Once disconnected is there any flow of fuel that needs to be stemmed / does the new pipe need to be replaced immediately?
Do I need a new gasket for the plenum when I refit or / what should be used to seal it back in place?
Many thanks
Roger
Thanks for the quick response.
Can't say that I was happy with the thought of driving it although the leak appears to have stopped, which I find a bit odd.
I assume its just a case of undoing the 6 hex screws and lifting / drawing the plenum forward, disconnecting the minimum number of ancillaries until there is enough room to get to the pipe.
Once disconnected is there any flow of fuel that needs to be stemmed / does the new pipe need to be replaced immediately?
Do I need a new gasket for the plenum when I refit or / what should be used to seal it back in place?
Many thanks
Roger
hi Roger, first disconnect the stepper motor plug on the back of the plenum, then remove the air intake pipe, undo the 6 bolts that hold the plenum on, then with the throttle cable still connected lift the plenum up and position it somewhere out of the way.
if you leave the car with the ignition turned off for an hour then there will be no fuel pressure in the pipes, but there will be fuel inside the lines and the fuel rail that will drain out, so have a few rags to hand to soak it up.
with the plenum out of the way you should be able to reach down to the end of the fuel line where it fits onto the copper pipe above the bellhousing, undo the clips with a long screwdriver, or socket and some extensions, it is tricky, but can be done.
once you have replaced the pipes and any spilt fuel has dryed up, turn on the ignition to let the fuel pump prime and check for leaks, if all is okay then refit the plenum, there is no gasket, so just use a smear of silicon around the joint faces then bolt it back on and replce the stepper plug, and refit the intake elbow.
if you leave the car with the ignition turned off for an hour then there will be no fuel pressure in the pipes, but there will be fuel inside the lines and the fuel rail that will drain out, so have a few rags to hand to soak it up.
with the plenum out of the way you should be able to reach down to the end of the fuel line where it fits onto the copper pipe above the bellhousing, undo the clips with a long screwdriver, or socket and some extensions, it is tricky, but can be done.
once you have replaced the pipes and any spilt fuel has dryed up, turn on the ignition to let the fuel pump prime and check for leaks, if all is okay then refit the plenum, there is no gasket, so just use a smear of silicon around the joint faces then bolt it back on and replce the stepper plug, and refit the intake elbow.
Edited by clive f on Sunday 27th June 21:37
Barreti said:
Fuel hose is 8mm Internal Diameter as you said Clive.
think you need to see this mate, LG put me up to it ..........honest
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
THERE ARE TWO PIPES THAT NEED REPLACING.... I only shout because I missed one myself
There's the feed pipe which you need to pop the plenum to replace, there is also a return on the other side of the car which disappears down behind the O/S exhaust. It's a right t
t to get on but a bit of silicon spray makes it a million times easier!
DO BOTH
There's the feed pipe which you need to pop the plenum to replace, there is also a return on the other side of the car which disappears down behind the O/S exhaust. It's a right t
t to get on but a bit of silicon spray makes it a million times easier!DO BOTH
BliarOut said:
THERE ARE TWO PIPES THAT NEED REPLACING.... I only shout because I missed one myself
There's the feed pipe which you need to pop the plenum to replace, there is also a return on the other side of the car which disappears down behind the O/S exhaust. It's a right tt to get on but a bit of silicon spray makes it a million times easier!
DO BOTH
Just to point out that both pipes are next to each other, and connect to the fuel rail just below the bonnet catch/ stepper motor area.There's the feed pipe which you need to pop the plenum to replace, there is also a return on the other side of the car which disappears down behind the O/S exhaust. It's a right t
t to get on but a bit of silicon spray makes it a million times easier!DO BOTH
Also just to add, if those pipes are old then best to check the pipes around the fuel pump and filer at the back of the car as well. They are much easier to change
Edited by crackedfinger on Monday 28th June 10:36
The beast lives again, subject to a test drive!!!
Changed both fuel pipes as suggested, had to disconnect heater hoses in the end to get to the lower one, so back to bleeding the system again! The fuel feed was OK but changed it anyway, it was a right s_d and took ages of fiddling below the manifold to get the pipe off and on, far worse than the other one.
I have added changeling the other fuel pipes to the list of jobs.
Many thanks for all your advice, especially the concise instructions from Clive.
Couldn't have done it without your input.
Thanks again.
RAS
Changed both fuel pipes as suggested, had to disconnect heater hoses in the end to get to the lower one, so back to bleeding the system again! The fuel feed was OK but changed it anyway, it was a right s_d and took ages of fiddling below the manifold to get the pipe off and on, far worse than the other one.
I have added changeling the other fuel pipes to the list of jobs.
Many thanks for all your advice, especially the concise instructions from Clive.
Couldn't have done it without your input.
Thanks again.
RAS
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