Fuel filter orientation

[gtsdls]

I have a 1974 914 1.8.

While doing a rear caliper rebuild, I moved the fuel line going into the gas filter just to look at the filter- it now leaks (it's now off and it wore thru at the enlarged end of the nipple on the filter).

The filter is a Kaiser rectangular box variety- both ends are the same diameter. The directional arrow on the filter was pointing toward the plastic line coming out of the bulkhead and away from the fuel pump.

Is this the correct orientation?

What sized fuel lines should be used to interface to the original plastic lines?

Where can I obtain the correct box filter (my car has the correct holding bracket for it)?

[Dave at Pelican Parts]

Fuel flows in the direction of the arrow, just like Haynes says. Haynes doesn't state it very well, but that's indeed what they're saying.

The original filter, I believe, had the same size inlet and outlet fittings on it, just like yours. There is one available (not sure if it's from a different year 914 or from a different car) that has the ~9mm inlet and a ~7mm outlet. That way you just hook a fatter hose from the center tunnel line to the filter, and a thinner one from the filter to the pump.

The original setup requires a "converter" hose that is probably still available from the dealer or from us (not sure), but is $$. Or you can probably fake up something from brass plumbing supplies.

We can supply you with the correct box filter--all of the OEM 914-4 filters that I know of were box-shaped. Again, see Haynes.

If your fuel line cracked when you moved it, it was well past its "replace-by" date. You should replace all of the fuel hoses on the car, because chances are they're all the same age. And ones that leak on top of the engine will leak onto very hot spots, which can cause fuel fires. Which are Very Bad News.

--DD

[gtsdls]

Is the fuel flowing into (returning to the tank), or out of (going to the fuel pump) the larger of the two plastic hoses?

The arrow on the top of the removed filter was pointed toward the plastic bulkhead line, and away from the pump. It was replaced sometime in the past and could have been installed backwards.

Adding to the confusion- I have a Purlator F23175 that I bought locally today. It has the 7 & 9 mm connections mentioned above. The arrow points toward the large end, i.e the reverse of what you remember above.

I have a 3 connection fuel pump, top to bottom oriented.
* The top connection is connect to the fuel filter, then the large bulkhead line.
* the middle goes up thru the engine tin
* the bottom splits into two and goes up thru the engine tin, and connects to the small bulkhead plastic.

PS- the rubber line is what broke at the fuel filter

[gtsdls]

Bosch makes the E1000-29268 replacement filter with double 8mm connections. I just want to be sure of correct orientation since:
* The Purolator appears to be designed backwards
* the old filter was installed backwards

[Dave at Pelican Parts]

If it has two small connections, you'll have to do some creative adapting. Or buy the $$$ converter hose.

The larger fitting would come from the tank, the smaller fitting would go to the pump.

The pumps 3 fittings should be labeled "S", "D", and "R". S stands for Suction (or the German equivalent), D stands for Druck (German for "pressure"), and R for Return (or the German equivalent).

The "S" line will come from the fuel tank by way of the larger fuel line and through the fuel filter.
The "D" line will go to the right-side fuel rail.
The "R" line will go to a Y-shaped fitting, which has one branch going to the return (smaller) hose through the center tunnel, and the other of which is hooked up to the fuel-pressure regulator in the right-rear corner of the engine bay.

--DD