FASS Tech 101 (Leaking Fitting) The FASS tech department receives calls everyday with questions that range from … Titanium Series How A FASS Works. Both of these problems cause the fuel pressure to drop, starving the carburetor of gasoline and creating the above symptoms. Once the (2) fuel pump mount This prevents fuel from leaking into the builge which in a boat could be instant deaster. Leaking fuel from pump.seems to be a little hole on under side of pump just below the pressed metal join. If this is a mechanical pump located on the side of the engine then what you are most likely seeing is fuel dripping out from the weep hole in the pump. Reinstall the spacer plate, use a new gasket. The pump was replaced by the PO about 4000k miles ago. The oil that leaks out that way is getting slung up from the cam eccentric or the timing chain. The phone calls are prompted by the website and not by me, we can do this with out a call. If you were in there recently for the hoses double check and make sure you do not have anything loose and leaking. New pump would be $8000 plus. I got here a leaking mechanical fuel pump on a 3304 PC engine. The ignition or powertrain control module (PCM) usually controls When a Crankshaft – Camshaft Position Sensor goes BAD, your vehicle will not start. When the internal diaphragm leaks, fuel escapes through the weep hole to notify the vehicle owner of a malfunction. When the diaphragm goes up air comes out of that hole when it goes back down air rushes back in. There is the weep hole that will leak if the pump is bad and the large bolt on the back is the banjo bolt which has the fuel going through it to the back of the heads. Page 1 of 2 - Fuel Pump Leak - posted in Problems, Questions and Technical: Hi I have just got our 1988 Mini City back on the road after being laid up for a few years. ... Water pumps can sometimes support a mechanical fan. fuel pump was leaking oil from weephole,replaced with new pump and it's leaking too,can anyone tell me why this is happening?i've changed oil filter,pulled pump apart diaphragm was good & cleaned pcv port to carbany ideas? On top of oil in the fuel and fuel in the oil, oil from the pump weep hole usually ends up on the ECM and over time softens the wiring harness seals that leads to headaches down the road. GrapeApe, Aug 4, 2015. Your diaphragm is broken and it will not pump fuel with a broken diaphragm. Okay, thank you for the clarification, If the only thing that is leaking is the fuel pump from the weep hole then there really is nothing else that will need to be replaced. Pressure Fuel Pump Weep Hole for Heavy Duty DD Engines Summary: Occasionally we see trucks come in with fuel leaking from the high pressure fuel pump weep hole. There's usually not much pressure behind the pump and if the diaphragm is ruptured, the oil will be diluted....at least that has been the case whenever I ran across ruptured diaphragms. My fuel pump is leaking from the Vent hole. I took it apart, cleaned it, & swapped the red pumps spring into it- it holds steady 5.5psi and no leaking. I am just curious if I could get away with just replacing the front lip seals of the mechanical fuel pump … With the gasket on the fuel pump insert the fuel pump arm into the hole … This is NOT a defect in the pump and further diagnostics need to be performed to find the root cause. The mechanical fuel pump on my 240Z is leaking oil from a small vent hole in the side of the pump body near where the pivot pin is. and i guess some of the 1980's must have too. When my fuel pump went bad, it started leaking fuel into the oil pan. I took everything apart assuming there would be a gasket or seal between the pump body and the motor but there isnt one. ... they get brittle and are not expensive. But, after seeing the weep hole/vent on top of the fuel pump spit oil I confirmed it. Fuel may leak from the weep hole which is located on the bottom of the Stanadyne Model DB4 Fuel Injection Pump, near the pump mounting flange. 01-04.5 LB7 Duramax Powertrain > new water pump leaking from weep hole So my original water pump went at 126k. Coolant level is fine. Fuel should not come out of here and it means that your fuel pump diaphragm [inside the pump] has developed a small hole and is beginning to leak fuel and should be replaced. I'm no professional so I had the dealer do it. ANyone here running a HOlley Electric fuel pump? I’m guessing the leak is coming from the weep hole on the pump. I was pretty confused as that is a fuel line, not oil. Yesterday I noticed that it was leaking fuel. I rebuilt the turbo and fuel bowl last summer and replaced all the washers and sleeves for the fuel so I should be good to go. They can be re-inserted with the washers under the head thereby preventing contact with the rod but sealing the hole. my 79 truck came with an electric fuel pump and the head had no place to mount a mechanical pump or power steering pump. Many inexpensive When the internal diaphragm leaks, fuel escapes through the weep hole to notify the vehicle owner of a malfunction. That is not a weep hole, it is a vent to allow the diaphragm to function properly. I didn't know anything about a weep hole or mechanical seal or anything at that time. Most of the time when a pump fails it leaks fuel out a weep hole so it wont flow into the engine but. An engine that misfires, runs lean, hesitates, or stalls could have a leaking diaphragm or valve within the fuel pump. My fuel pump is leaking from the Vent hole. The car was just sitting and I started smell fuel and I went out to the garage and found fuel poring out of the hole. I have a 1968 AMC AMX 290 automatic w/electric wiper motor. I am getting the same problem. I have allot of oil coming out of the weep hole under the water pump. I figured it needed a new gasket and o-ring and I would replace them before I put the carbs back on. Many times the leak is just the rubber hose. AutoZone.com Spectra Premium Fuel Pump A1001MP - Read Reviews on Spectra Premium #A1001MP A mechanical OEM style pump can pump fuel into the crank case or externaly some cases both. Watch this short but great visual representation of how a FASS Titanium … How A FASS Can Help Your Duramax Diesel. This is the second time this year. Reinstall the spacer plate, use a new gasket. Oil shouldn't leak out of your mechanical fuel pump weep hole because you're not feeding any pressurized oil into it. It has only 154 miles on it right now, but at about 100 miles it mysteriously had an oil leak. Had it replaced with a Napa water pump which started leaking a few thousand miles later from the weep hole. Fuel leaking out of the two vent holes at the top of the casting. (I am getting oil out of the weep holes on the fuel pump), pvc is working no smell of gas on the dipstick. Fill pump reservoir with fluid. * There is what looks to be a weep hole right in this area where the lock nut for one of the bolts is. Disassembled the pump and the diaphragm was cracked forcing fuel to the upper cavity. The car was just sitting and I started smell fuel and I went out to the garage and found fuel poring out of the hole. Re: holley blue pump is leaking- update & fixed *update- the internal regulator apparently wasn't allowing the pressure to bypass back to the low pressure side & that little hole must be a weep hole for fuel going to the fuel pump motor. Not many pumps have these holes. Generally the unit will come in with a complaint of a fuel leak at the fuel pump. New Water Pump Leaking From Weep Hole - Chevy And Gmc Duramax Diesel Forum. I just had the same problem with my roadster. I agree with Bill. First symptom was diesel in engine oil and eventually constant fuel leaking out of weep hole. The leak is normally observed on a cold engine and is aggravated by cold weather. It seemed ok for a while but now it leaking … I searched everywhere until I finally isolated the leak to the fuel pump or in-line fuel filter. My Holley mech pump took a dump about a month ago, thought I had a line leaking, come to find out there was something like a weep hole built into the body of the pump, with the motor started it would pump gas out that little hole, still don't know why the hole is even there, but had to replace it for the time being with a factory replacement type for now. Most mechanical fuel pumps have a weep hole on the bottom side of the unit. A mechanical OEM style pump can pump fuel into the crank case or externaly some cases both. Does the pump have a 2nd smaller nipple for a smaller rubber fuel line like this. The fuel pump is leaking oil out of a threaded port; between pump and motor. There are marine style mechanical pumps that have a tube on the weep hole that a hose is attached to and it is routed into the carb which is also a marine unit. Every now and again petrol is leaking from around the fuel pump while the engine is running. I have replaced 2 fuel pumps. has anyone ever herd of this? A coolant leak coming from the weep hole is a sign of water pump bearing or seal failure. This prevents fuel from leaking into the builge which in a boat could be instant deaster. Had an old AC mechanical pump, #40083, that was used at least 10 years ago. If a mechanical pump leaks fuel at the weep hole it is defective or damaged and nothing done external to the pump will correct the problem. I replaced the mechanical seal behind the water pump and it still leaked. I Think the Mechanical Fuel Pump Is the Culprit! The weep holes on a fuel pump should leak fuel at worst. Joined Jul 15, 2013 Threads 155 Messages This weep hole often resides between seals that separate the oil side from the coolant side. The pump has about 30k miles on it. I am on the third one in months leaking out the upper body weep hole, The first one was a blue about 4 years old, replaced the gasket, still leaked, replaced the housing ,less leak but out the weep hole, Got a new summitt pump and it lasted about 7 weeks and its leaking out the weep hole too. If this is a mechanical pump located on the side of the engine then what you are most likely seeing is fuel dripping out from the weep hole in the pump. OIL LEAK SOUNDS LIKE TO ME EITHER THE FUEL PUMP DIAPHRAM TORE,or oherwise let go.The hole you are refering to (if i'm reading this correctly)is called a "weep hole".Just like the one on your water pump.It's there to signify an internal pump malfunction .I woulld check to make sure you don't have gasoline mixed in that oil you are leaking,check your dip stick,smell it, don't … This leak may be anything from a few drops to a steady stream of fuel. Most fuel pumps have a weep hole that will leak oil if the internal diaphragm ruptures, this could also dilute the oil with fuel. Its leaking from the area where the electric motor bolts to the pump body. So I proceeded to remove the carbs and came inside and googled "cx500 water pump gasket". It does not happen all the time but when it does it looks like fuel is being pumped out from beneath the pump its self. I removed the fuel pump and both gaskets and the spacer are there so the pump looks fine. On V8 engines, a push rod between the camshaft eccentric and the fuel pump operates the fuel pump arm.So, There are two holes in the passenger side front of the engine. Most mechanical fuel pumps have a weep hole on the bottom side of the unit. Re: Please Help - 20R Mechanical Fuel Pump Leaking Oil « Reply #7 on: Mar 11, 2008, 08:58:49 AM » the 79 came with an electric fuel pump in the tank stock. Sometimes that still happens and you full the crankcase with diesel. What benefits can you get by adding a FASS Titanium Series diesel fuel pump … M. mechanic mark Lawn Pro. That ruins the engine in short order too. The pivot pin was sealed with silicone by the previous owner (a common remedy), but the vent hole is leaking oil into the prop-wash of the cooling fan and spraying the plug-side of the engine bay.