Bus (74 Bay) was leaking fuel. Spent a couple of hours under the bus in the heat the other day draining the tank and replacing the drop line from the tank to the pump, which was cracked and perished at both ends. Noticed an aftermarket filter in the line, sitting on top of the starter motor, but figured it was best left in.

More fool me. I tightened the hell out of the clamp on the line where it exits the filter, and it didn't leak with 15L in it on Sunday, but as soon as it had a full tank today it's leaking again.

What should I do? Pull the filter out and throw it away, replace it with an unbroken line from the tank to the pump, with the caveat that the in-tank filter's 35 years old? Or put in a newer fuel filter with the caveat that line joins are leak-prone? What would you do, guru?

Replace the filter and lines and re-route it away from the starter motor
Under the car is the best place for the filter but try to keep it away from any electrics or heat....

OK so I put a longer line in from the tank port to a (new) fuel filter (glad I got it, the old one had things unknown to science in it) and cable tied the new filter to the bracket that supports the (unused at this time) heater duct, well away from the starter motor and the block.

So then the verdommt fuel pump starts pissing fuel out the front seal. Gasket's gone. My theory, and I'd love someone to correct me, is that if the gasket has gone the moment there's proper vacuum pressure in the system, then the pump probably has not been serviced since God was a boy. If, then, I replace the gasket, the valve will go; and so on. In a nutshell I ought to get a refurb or NOS pump, swap out, and fix the old one properly at leisure.

This bus is a daily driver after all.

Thoughts? Please? With a cherry on top?

It is not uncommon for other items in a system to fail if you replace one component due to failure.

Classic example is watercooled engines. People replace radiator hoses because they are perished, but fail to replace the heater hoses at the same time, and a blow out on the heater lines puts them stranded. Similar is when people replace spark plug leads. The distributor cap, rotor, plugs and points need to be done at the same time.

Is it a 1600? Fuel pumps are cheap. If it's not... I don't know what a later fuel pump costs, but a rebuild sounds liek a good idea. And as Helbus explained, once one part of any system lets go, it's a good idea to replace ALL the parts

It's an 1800, and the gasket kits are no longer available. Draining the tank again as we speak, it's been bleeding like a stuck pig.

So. The leak site is between the upper and lower main body housings of the fuel pump, not as I first thought from the front gasket. It kind of looks like there's a gasket in there, although I assume that it's actually a cork surround for the diaphragm. I'm stuck with fitting an electric pump as the solution, and it looks like the brand of choice is Facet which is available from Repco for about $135. The Facet pumps come in two ratings though - there's a 4-6psi and a 1.5-5psi. I think they're supposed to be motorbike fuel pumps. What I've read says the stock Solex carbs I've got won't deal with much more than 5psi, so I'd guess it's the weaker pump I need.

Also, I'd guess that if I left the mechanical pump in there without removing the armature, it'll eventually seize from running without fuel in it and damage the cam. So I either need to remove the push rod and put the old pump housing back on, or make a very thick stainless steel blanking plate and hand-cut cork gasket to blank the aperture.

Thoughts?

if you run an electric pump i think you are sposed to have a cut off solenoid in the line as well as fuel will still gravity feed thru the pump if your tank is over half full. then if your float valves don't seal properly your sump will be full of fuel...only what i heard

Well met, cap'n Rocknob. OK, I will sort this.

My understanding is that you are supposed to run the +ve line out of either the regulator or the coil so that the pump will not run when the donk is not running, but you are saying the gravity feed will override that beyond about 20L and keep dumping petrol into the sump so I need an additional cutoff in the fuel line to plug it when there's no burn. Makes sense.

Now, a gent I met this arvo mumbled something about bits from the EFI rig from a Commodore coming in handy, but he was drunk at the time and I was only a couple of beers behind him. Can you, or anyone you've met, or anyone else who reads this, suggest what part I need to block the fuel line and how best to wire it in?

I'll post photos of the whole process if you can tell me, for posterity. Promise.

Hi

You can use a fuel lock off from an LPG system to turn the fuel off, you could use this with a toggle switch as an anti theft device. I fitted Bosch tachometric relassy that I bought from a place in Peakhurst, I could find out the part number for you and the name of the place in Peakhurst, this will turn the pump on only when the motor is running.

Steve

That'd be great Steve, thanks! After a bit of shopping about for a pump (Wolfsburg quoted me $275 installed, then hung up on me while checking to see if the parts were in stock; Repco quoted me $135, said I'd need to drive to Dural if I wanted it this week, and suggested that I mill my own blanking plate) I got the exact same Facet pump, blanking plate and gasket from Classic Vee Dub in Rydalmere for $75 total. Bargain.

George from Classic Vee Dub said he has two busses running these pumps and he's "just got it wired to the ignition, nothing else - no problems, goes well."

I appreciate his stock and his prices but I think he might be barking mad. I don't fancy the idea of a pump that would run when the engine isn't firing. Where is that fuel going? No please. I carry my kids in this car.

There's an LPG fitting joint around the corner from me in Marrickville, I might go have a chat with them now, ask an opinion - they'll probably just tell me to go to Repco. Steve, I'd love the details of your rig - what the part is, where you've wired it in, and where you picked it up. Much appreciated. When I've got all the bits I'll take the camera out and document the install process, and post it back here.

k

Hi

Sorry I took so long to get back to you.

Bosch relay PN# 0 280 230 001 from a BMW 520i 1992, terminal information:

50: Start Signal (from starter or ignition switch crank position)
87: Switched 12 volts (out)
87b: switched 12 volts (out to pump)
31: Ground
1: negative side of coil (trigger to keep relay engaged - engine running signal)
30: +12 volts supply (switched 12 volts in )
15: +12 volts supply form ignition key

I bought it from Australian Fuel Injection South, 3/79-81 Boundary Road Mortdale, 02 9534 5222. I dealt with George.

They may have other relays that do the same job.

Steve