TheSamba.com :: View topic - Redoing entire fuel system ... got everything?

Tue Nov 10, 2009 12:46 pm

I'm wanting to redo my entire fuel system ... from tank back. My car has flakes of rust in it, and so far all the rust has been caught by the fuel filters. I've got some cash and I figure I should fix that first.

Figure new tank with all associated gaskets and hoses, fuel line (cloth woven, I assume?) from the tank back, new fuel pump, and do a carb rebuild to tide me over until I get dual carbs? Think that should do it or something else I should involve?

My fuel pump is good ... but it's some cheap Autozone variety I picked up when my other one went bad while driving down the road. Figure keep the Autozone one for a spare.

Tue Nov 10, 2009 12:59 pm

Unless your tank is rusted THROUGH, your most economical route will be to remove it, descale it, treat it and then reseal it. You'll also learn a lot about fuel that you don't know now in the process. Ask me how I know. :?

You neglected to mention what year and model car you have.

Buy the 5.5mm fuel hose (german) and dammit, use clamps everywhere.

Make sure your fuel filter is installed at the front of your car, under the gas tank.

Make sure the grommet is in place in the front tin where the metal pipe passes through it so you don't saw through the pipe.

If your fuel filter has been catching all of the rust (it is upstream of the pump...Right?) then you can just run with your current pump.

Save your beer and pizza money, avoid the dimebags and step up to a rebuilt squaretop pump, rather than buying a 'new' pump. Yellowbeard (see the classified) does beautiful work.

M

Tue Nov 10, 2009 2:24 pm

how do you move the fuel filter to the front? Do you have 5 gallon buckets laying around to drain the gas or do you just run it as low as possible then do the procedure?

Tue Nov 10, 2009 2:45 pm

The latter. I'm recommending the change based on the idea that he's going to have to drain and remove the tank anyway to descale and treat it.

Here's a rap I wrote some time ago on the fuel filter location:
Quote:
We've all seen it: The plastic fuel filter spliced in to the fuel line between the fuel pump and the carb. Even though the mechanical fuel pump only puts out a measley 2-3 psi, what in the world is THAT type of filter doing THERE? Consider: in your Beetle, there could be two fuel filters: one that is actually IN the tank, and another within the fuel pump itself.

Putting any fuel filter in-line between the pump and the carb is asking for trouble. I have learned this one the hard way: watching my engine catch fire! Next time you are at a show or your local VW shop, take a good look at those plastic filters, especially where the clear plastic body meets the flatter top: The two sections are simply heat-seamed together. After my 1971 Beetle caught fire (quickly put out by the extinguisher my father had MADE me keep on hand while working in HIS garage) I went on a little research trip to my VW shop, bought a fist-full of those cheapo filters. I tested them to see how hard it was to make them fail and was horrified to discover that it took less than 6psi at the heat-seam joint to cause it to start leaking. After that, I swore off those filters entirely and I hope everyone who reads this will be smart enough to do so, too.

So where does that leave us for a fuel filter, other than the over-coarse unit IN the tank? Most of the in-pump filters have long since hit the landfill and been replaced by stamped aftermarket replacement pumps that have no filter and can't be rebuilt. Some clever crumbs have spliced the filter in between the front engine tin and the pump, but this is still a poor location: right next to the cylinder head, it's a great way boil the fuel in the line or if you insist on using the plastic cheapo filters, maybe MELT the filter unit. And there is still the matter of leaks. Best to have as few potential failure points as possible OVER the HOT engine.

So where to put it? Yup, under the fuel tank. It's protected, cool, and if you commonly have fuel filter clogs, you need to remove and fix your tank rather than jus throwing another $.99 filter at it and having it clog again in three days.

While the plastic filters work OK in this location, I'm not taking chances: a Russell glass fuel filter is what lives in my Bug now and it lives in the under tank location. Cool, protected, reasonably easy to inspect, never needs to be replaced; if there's a problem, I remove and clean the 1 micron screen. At $12.00 USD, it is the cheapest insurance against an engine fire you'll ever buy.

Tue Nov 10, 2009 2:55 pm

webwalker wrote: Unless your tank is rusted THROUGH, your most economical route will be to remove it, descale it, treat it and then reseal it. You'll also learn a lot about fuel that you don't know now in the process. Ask me how I know. :?

You neglected to mention what year and model car you have.

Buy the 5.5mm fuel hose (german) and dammit, use clamps everywhere.

Make sure your fuel filter is installed at the front of your car, under the gas tank.

Make sure the grommet is in place in the front tin where the metal pipe passes through it so you don't saw through the pipe.

If your fuel filter has been catching all of the rust (it is upstream of the pump...Right?) then you can just run with your current pump.

Save your beer and pizza money, avoid the dimebags and step up to a rebuilt squaretop pump, rather than buying a 'new' pump. Yellowbeard (see the classified) does beautiful work.

M

It's my '74 Super.

I have one fuel filter underneath the tank and one between my carb and fuel pump. I know I need to get rid of the one between my carb and fuel pump - and I'm in the process.

I probably will just clean out my current tank. Just saw the prices of new ones ... thought they wouldn't be that expensive.

If I may ask, whats the difference with a squaretop pump?

ibjames wrote: how do you move the fuel filter to the front? Do you have 5 gallon buckets laying around to drain the gas or do you just run it as low as possible then do the procedure?

If I'm just adding a fuel filter (if the line is in good shape), I take a pair of needle nose vice-grips to clamp the line shut and cut it to add a filter.

Tue Nov 10, 2009 6:33 pm

Here's a procedure for restoring the tank. This is for a Bus tank, but the outlines of the procedure are the same.

http://www.ratwell.com/technical/FuelTankRestoration.html

This is a squaretop pump:

That big beautiful brass fitting in the front is where a screen filter goes.

Later pumps (including junk sold at Autozone, et all) are pressed together, have no filter, and are not rebuildable. After 30k, throw them away and buy a new one. The very best of disposable consumerism.

M