Front of the car oil leak

andreic · 08-01-2012, 11:12 AM

I have a separate question about my 1975 914 1.8L. I have a pretty serious oil leak from the engine; I think it's from the oil cooler seals, but I'll have to dig some more into it. The oil leak is such that I lose about a quart of oil in 30 miles of driving, and I have oil dripping from all over the engine, and the upper part of the engine is coated in a light film of oil.

However, after having the car sit for a couple of hours in my garage, I noticed another, smaller puddle of oil under the front of the car. Peering under, I saw a plastic hose end sticking out maybe 1/2" from under the compartment that holds the fuel tank, etc. Oil was coming out of there. My question is, where is that hose coming from? What is it for? I saw something in a photo that said it was a water drain, is it coming from the engine compartment? Could it be collecting oil from the engine compartment and draining it in the front of the car?

TheCabinetmaker · 08-01-2012, 11:50 AM

Quote:

Originally Posted by andreic

I have a separate question about my 1975 914 1.8L. I have a pretty serious oil leak from the engine; I think it's from the oil cooler seals, but I'll have to dig some more into it. The oil leak is such that I lose about a quart of oil in 30 miles of driving, and I have oil dripping from all over the engine, and the upper part of the engine is coated in a light film of oil.

However, after having the car sit for a couple of hours in my garage, I noticed another, smaller puddle of oil under the front of the car. Peering under, I saw a plastic hose end sticking out maybe 1/2" from under the compartment that holds the fuel tank, etc. Oil was coming out of there. My question is, where is that hose coming from? What is it for? I saw something in a photo that said it was a water drain, is it coming from the engine compartment? Could it be collecting oil from the engine compartment and draining it in the front of the car?

golly oil up front? You'd know if it was gasoline from the smell, so thats not it, it should not be oil (unless a spare bottle of oil leaked in the frunk (Front tRUNK))

My guess is that you have found brake fluid under the front of the car. jacker her up safely secured and remove the rockshield that is below the master cylinder. i'd bet she has a leak. A test for brake fluid other than smell is to test if it will combine with a drop of water or not. oil will stay seperate from water, brake fluid will combine.

the oil leak in the rear might be a weeping oil pressure switch, located on top of the motor near the distributor. it leaks and the oil from it goes right on top of the oil cooler, pretending to be an oil cooler leak. cheap part and very easy to remove / install, so check it BEFORE pulling the oil cooler. you might be lucky on this one.

andreic · 08-01-2012, 12:31 PM

I looked at the brake pump, and there did not seem to be anything leaking. And as I said, the oil seemed to be dripping from a plastic hose that comes from the body; in the center of the car, maybe 10 inches behind the brake pump.

914-6Porsche · 914-6Porsche's Garage

On my-6 the brake fluid was leaking from the shaft on the inside under the covering board for the pedals

andreic · 08-01-2012, 06:30 PM

Brake fluid it seems to be, as it did combine with water to produce a white-ish mixture. How do I remove the floorboard that covers the pedals to look under there?

Dave at Pelican Parts · Dave at Pelican Parts's Garage

There are three Allen-head bolts you remove. They're pretty obvious once you peel back the carpet. It's a pain the wiggle the board around the clutch and brake pedals, but it can be done. I find that removing the pedal pads helps a little.

--DD

TheCabinetmaker · 09:22 AM

the only drain tube I can think of for the brakes is a little clear hose that comes off the top of the reservoir , in case the resorvoir is over filled, this tube will drain the fluid to under the car. could this be the the source of the leak? I am not aware of any drain tube from the peddle area, however if your master cylinder leaked near the push rod, pooling fluid could find a hole in the underside of the car and drip there, usually it just pools under the carpet and plywood peddel board.

remove the drain tube from the top of the reservoir and blow thru it, and see if that forces stuff out of the mystery tube that you have under the car. if so, maybe this is simply a case of an overfilled reservoir.

jeffs9146 · 08-02-2012, 03:51 PM

The tube is the overflow drain for the fuel tank! It attaches near the fuel filler. There should not be oil coming from the front unless you have an external oil cooler or, as stated before, there was a bottle of oil that broke open in the trunk! I would think that if the brakes were leaking that bad you would know it by the feel for the pedal!

andreic · 08-03-2012, 06:44 AM

I am convinced it is brake fluid now, and I think it's not coming from the actual hose, but other leaking down from around it. I washed and dried the area around the master cylinder, and after driving it for 20 miles the area around it (under the car) was again wet. I removed the wooden floorboard around the pedals, and at the base of the pedals it is dry.

I suspect that the master cylinder is leaking around the main shaft, and the fluid collects in an area between the outer and the inner walls, and finding its way out around the plastic hose. Just in front of the plastic hose opening there is an inspection port (behind it there a the fuel lines from the tank and what appear to be some flexible brake lines) and putting my hand inside this inspection port I can feel more brake fluid.

I just ordered a replacement master cylinder, hopefully this'll take care of the leak.

TheCabinetmaker · 08-03-2012, 07:42 AM

sometimes the fittings on top the master cyulinder leak, that could be the source of the leak if you didn't see any leak at the pushrod end of the cylinder. if that is the case, you wont need a new cylinder. You will need the new rubber stopper part that the hoses press into. This is the supply from the resevoir fitting I refer to it is a rubber part

andreic · 08-03-2012, 01:37 PM

The confusing thing is that even though there is no fluid at the pushrod end, there is wetness on the outside mounting wall around the master cylinder, and there is brake fluid coming out from under the inspection hole I mentioned earlier. This second source of fluid appears to be coming from some leak inside the small compartment that is in front of the passenger's feet. (This compartment has two holes on the bottom, one of which is where the plastic drainage tube from the air intake above. I think this compartment is also connected to the center tunnel through which the main line to the rear brakes goes.)

Do you think I could be having two separate leaks, one at the master cylinder fittings and a hole in the line that goes to the rear brakes, somewhere behind the wall where the master cylinder mounts?

TheCabinetmaker · 08:39 AM

ok not sure what you saying when you say "the inspection hole" if the pushrod end of the cylinder is dry, it is likely there is no external leak in the seal. Do the brakes work otherwise? any signs of air in the system (ie you need to pump them)? does the peddle action seem normal or not?

You mentioned the drain holes /tube for the cowl air box, there should be two of them and they should be black plastic, about an inch in diameter.

Have you removed the under car cover plate yet? (secured by two torsion tube brace bolts, and two smaller screws, this plate is about two feet by about a foot wide)

if that plate is removed, you will be able to see the master cylinder.

if you have a leak that appears to be coming from above the cover plate, it could be .........

...
1. failure of one or both of the rubber plugs that attach the reservoir tubes to the master.

2. failure of the reservoir hoses that attach to the rigid tubes.

3. failure of the reservoir

4. the brake warning switch(es) on the cylinder can leak, replace if that's the case Often this kind of leak only happens when the system in under presure (brakes applied)

any of these things can cause fluid to pool and leak from the cover plate.

Also if at one time someone over filled, or spilled whilest filling the reservoir, the fluid will run down the body, next to the gas tank, and pool on the body and then slosh around and appear as a leak

In all these cases, find the source of the leak and wash all all fluid off the painted surfaces. Gas tanks have rusted from the outside because brake fluid soaked into the felt pads that the tank rests on.

It is possible for the metal pressurized brake lines to leak that could happen, but it is rare.

andreic · 08-06-2012, 03:37 PM

Let me be more clear. My car came with no rock guard (or cover plate, as you call it) to cover the steering mechanism and the master cylinder. They are out in the open. So when I was talking about the leak before, everything I meant was what I could see with the cover removed (i.e., missing).

I can clearly see the master cylinder on both sides, both outside and inside the metal wall where it is mounted. As I look at this wall, from the front of the car, under the car, there are three holes in it. Through a big one the master cylinder goes. To the left of the MC, about 8 inches away, one of the metal brake lines goes through, surrounded by a rubber grommet. Finally, about 10 more inches to the left, there is a big (4 inches diameter) round hole which appears to be an inspection port. This inspection port is roughly straight in front of the passenger's feet, but the passenger's feet wouldn't rest on it -- there is another metal wall that starts above this inspection hole, and goes down and back towards the back of the car. This wall, along with the bottom of the car and the initial wall form a triangular prism, and the inspection hole is on one side of it.

On the bottom of this prism there are two other holes, one which is empty, and a second one through which there is a plastic tube which ends about 1/2" from the bottom of the car. I am sure that it is a water drain from the air intake at the top of the car, just in front of the windshield. It is around this plastic tube that I see brake liquid leaking (mostly), although there is some wetness also around the MC and below it. I concluded that somehow brake liquid gets inside the "prism", but I can't figure out how. I don't understand this at all; how does the brake liquid get from the MC to the prism -- the prism ends about 5 inches to the passenger side of the MC, and the only thing carrying brake liquid inside there is the metal line that goes to the back of the car.

The brakes work fine, no pumping or losing pressure at all. The area inside the car is perfectly dry. From when I started to investigate this problem the level of the brake fluid in the reservoir has gone down about 1/2"

Any suggestions, highly appreciated.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

You're talking about the bottom of the compartment where the fuel tank lives. If you look up through that ~6" round hole, you can see the bottom of the fuel tank, and the lines from the tank to the center tunnel hard lines.

If what you are seeing is truly brake fluid, it is coming from the reservoir. The brake fluid reservoir is up behind the fuel tank in front of the driver. It has two hoses that go down to the master cylinder. Those could possibly be leaking. If they're leaking in the middle, it may be possible for some of the fluid to run down to the area under the tank in the middle of the car. I am not certain.

Brake fluid eats paint. It usually takes a little while to do so, but if it really is brake fluid you will probably have some bare metal in the fuel tank compartment. Which is not a good thing, because moisture can still get in there and start rust going.

I am going to suggest that you remove the fuel tank and see what the heck is going on in that compartment. You may need to repaint some of the tank's exterior, or it might be leaking itself, or something else might be going on.

--DD

TheCabinetmaker · 08-07-2012, 01:22 PM

So if that is the case, the leak is likely Number 2, or 3 that i wrote in last post, or the reservoir was over filled at one time.

the lines from teh reservoir have some flexable rubber hoses sections, that can fail, usually the hard3plastic line does not fail. at anyrate they run down near the gas tank, driver side, and if the hoses, lines leak, or spills at the reservoir happen, fluid will run down and pool under teh gas tank, that inspection hole you talk of is likely teh gas tank bottom's insepction hole, you can feel around for the gas tank hose thru the hole.

Pull the gas tank if there is corrosive fluid under the tank (sounds like you say there is) you may find the source of the fluid, as a broken fluid line/hose, or you only see the remains of a brake fluid spill/over flow

good luck

andreic · 08-12-2012, 08:12 PM

Indeed it was one of the flexible plastic lines that were going from the brake liquid tank to the master cylinder. The line had a crack fairly close to the reservoir. I cut the line an inch below the crack, and put a longer blue hose (the special one that does not get eaten up by the brake fluid) form the reservoir. Then washed down well the whole area, rust treated/primed/painted where the paint was eaten up, and put the fuel tank back in. Problem solved!