Replacing Fuel Filter ... and the tank

Check out the shavings ...

Turns out my tank (original from May '72) is metal - and it's badly rusting. Mike Drew passed along his suggestion for rigging up a 'pool sweep' to take care of the sediment on the bottom of the tank - and Jack DeRyke provided instrutions for removing the fuel filter-sock on the tank bottom. Both of these fixes will take me a few days to get the parts together ...

In the "off-season" (remember, I live in Canada) I am probably going to replace my old tank with an aluminum one. Any suggestions for where I should source an aluminum tank for a '72 Pre-L?

My first thought is you can buy a LOT of filters for the cost of a new tank. And your labor to keep replacing filters will take years to equal the labor to remove the engine and then the tank. And of course, once you remove the engine ....

Yup, you'll wind up doing ALL SORTS OF THINGS.

Which will equal lots of time AND money.

But, I believe Hall sells a stainless version. Not aware of anyone offering one in aluminum.

Larry

Fuel Filter replaced ... check

Fuel lines replaced (from banjo fitting on tank to fuel pump) ... check

Ignition ... check

Idle ... check

25 mile run ... running better than ever!

Tank gets to 1/8 ... clug, clug, stall

Trailer car home ... check

Throw up on lift - open fuel tank bung ... check

Have a look at what comes out ... yuck

Start prepping 'fuel sweep' to suck all the shit out of my gas tank ... stay tuned

The above sediment is from 1.5 litres (1/3 gallon) of gas from the dead bottom of my tank.

This is not really recommended but it works. On my previous Pantera I had the same issue. We drained the tank and then used a garden hose with a power spray head to wash out the interior of the take. Then made sure it was dry before resealing it and putting gas back in. Better than the labor cost of pulling the engine and tank, and can be done in an hour or two.

I think I have (had) the same problem. The new float for the tank got stuck in the bottom of the tank. Turns out the tank had about an inch of rust sediment in the bottom of the tank. Flushed the tank out with water(alot of water) and let it dry. I am on my second fuel filter in 50 days. The first one plugged up so bad it would shut the engine down at 3500 rpm (under wot). I am trying to deciede if i should take the tank out in the off season and replace it or send it to have it professionally cleaned or just wait and see what happens. The second filter seems to be doing pretty well so far. To remove the tank the engine needs to come out again so the wait and see approch is high on my list right now. I guess it depends on the fuel filter(S) hold up over the rest of the driving season.

Ed.....

While I am tempted to drain all the fuel and toss the garden hose in the goose neck up top, I am going to rig up a 'pool sweep' as suggested by Mike Drew and suck all the shit out of the bottom of my tank.

Pictured below, Mike described this setup as follows:

This is the heart of the apparatus--an aluminum tube, some fuel line, and a filter. The other end of the hose attaches to the inlet side of an electric fuel pump (not shown). Another hose goes from the outlet side of the fuel pump, back into the gas tank.

There's no need to be overly elaborate with your fuel pump either--any external electric pump from a junkyard will do fine (most VWs, Audis and other German cars have a very nice Bosch pump that's perfect for this job).

See the filter in the picture? DO NOT use this type on your car! Many marshmellows have been roasted when they fail, and they do regularly.

...I second that! Those Glass filters have very thin and weak 'Pot-Metal' threads!! One of those things came apart in my bare hands while the electric pump was operating! I was simply checking to see if it was screwed together tight when it fell apart, Not Smart! I was lucky, No Sparks in the Area!! I took the Damn thing off and replaced it with one of those reliable Steel Canister Filters...

quote:

Originally posted by edmguru:
See the filter in the picture? DO NOT use this type on your car! Many marshmellows have been roasted when they fail, and they do regularly.

The glass filter simply allows you to see what you suck out of the tank, using the aforementioned 'pool sweep.' I would never use one of those in my cat; in fact, I'm thinking about beefing up my fuel line with two filters - both installed upstream from the fuel pump.

Upon further inspection, I am convinced that the issue lies within the confines of the tank.

I forgot to mention that when I pulled the banjo fitting to replace the fuel lines, there was some black goo in the cavity of the banjo bolt. Well, I think that is from the fuel spout's gasket, which is badly worn. See pic below ...

I am also thinking that my fuel sender assembly is shot. And, apparently there is a fuel filter-sock on the tank bottom (at the end of the sender assembly) that will have to be blown off and then retrieved with chop-sticks.

All in all, I am still under $10 in repair bills ... and I'm keeping my fingers crossed until a new tank can be installed over the winter!

Erik,

You do know that replacing the gas tank involves removing the engine, right? There are stainless tanks available from several vendors, but I have not seen an aftermarket aluminum version. Only the very first Panteras had aluminum tanks.

I was advised that filters should only be place after the pump because pumps are typically designed to have push resistance and not pull resistance.

Make sure you replace all those old, brittle vent lines while you're at it. You might even consider changing the fuel pump after you get all the crap out of the tank. Chances are pretty good after that much crud passing through it will be the next item to fail—especially if it's the original. If you have a stock engine, the stock-style Carter pumps are reasonable, available and cheap.

Good luck with the cleaning!

Mark

The OEM carb with screw in filter clogs easily. I always kept 2 spares. I learned the hard way that you never want to be running the last few gallons of gas.

I wanted to drain and flush the tank but the drain plug was flexing the bottom of the tank. Decided that it was easier and cheaper (new Tank/pulling engine)to just clean the filter 3 times a year and always keep at least a qtr. tank. I think I will try Mike's "pool sweep”. Not a total clean but better than nothing.

After replacing the carb/manifold I went with this filter which has a cleanable screen. It is located at the back of the manifold and is easy to service.

You know what is really funny, I ran one of those glass filters for years with no problems. Well, sort of no problems. The car ran great until it was about 5500 rpm, then it just lose power. But doing a burnout I could turn 8000 rpm. Scarry on stock rods. What I did not realize is that that little 1/4 inch fuel filter was causing me to run lean at high rpm. Oh well.

Anyway, I would pull the drain plug and then pressure wash out the fuel tank. Then spray in some Zinc coating like POR metal ready normally used for auto body to help bond any remaining rust to the tank. Then just fill it back up.

Well, I do not have the time to pull my engine/ZF and tank right now. (It's driving season up here in Canada, eh!) I’m thinking that I will do the following:

- drain the tank (I have a lift so this is easy)

- attach a threaded coupling in the fuel drain’s hole, which will connect to a garden hose and run into a large Rubbermaid garbage can (to collect the forthcoming debris).

- lower my cat a bit (on the lift) and remove the fuel ‘goose neck’ filler (I have to replace the gasket anyway) … then use my pressure washer to spray the walls and bottom of my fuel tank and have all the waste water from the tank drain from the garden hose through some filters and then into the garbage can (just to see what’s coming out).

- after pressure washing is complete, I will rig up my shop vac hose to get it down to the bottom of the tank. This will both suck up the debris remnants as well as take care of any water remaining in the tank.

- if I have a few days to wait, I would then add a dilute solution of phosphoric acid to cure and harden the innards of my tank … and then rinse again with my pressure washer.

Wish me luck, boys. I'll keep you posted ...

quote:

Originally posted by Mark Charlton:

I was advised that filters should only be place after the pump because pumps are typically designed to have push resistance and not pull resistance.

Interesting. I have a single filter today, which is located in the common position just after the banjo fitting coming from the tank. I was thinking of placing a second (larger) filter after the pump, but that will take some work as I have steel line running directly from the fuel pump to my carb. I wonder if I should replace that steel line with braided?

quote:

Make sure you replace all those old, brittle vent lines while you're at it. You might even consider changing the fuel pump after you get all the crap out of the tank. Chances are pretty good after that much crud passing through it will be the next item to fail—especially if it's the original. If you have a stock engine, the stock-style Carter pumps are reasonable, available and cheap.

Yep, I eventually plan to replace all my lines with top-of-the-line braided or whatever is best. The 'offseason' will allow me to pull the Cleveland and ZF - to inspect and replace components like the pump (if needed) - but for now I am trying to get back on the road as quickly (and reliably) as possible.

Thanks for your feedback, Mark.

Erik,

I wouldn't replace the solid line, just anything that is flexible and looks like it came with the car.

Fuel filter type and placement are critical to achieving the proper fuel pressure and volume to the carburetor. A high-flow, fine-element fuel filter should be used between the fuel pump and carburetor on the pressure side, not between the tank and the pump on the suction side. Between the tank and the pump you may want to run a coarse-filter screen no finer than 100-micron (if you're still concerned about crud after the clean-up). This is because as a pump pushes, it also has to pull, and when a pump has to pull too hard to acquire fuel through a restrictive filter, a vacuum or low-pressure area develops at the inlet. A restrictive filter on the suction side of the pump may fail to flow the full volume of the pump and result in cavitation at the pump inlet.

The fuel pump is replaceable with the engine in the car, you just need small hands and thick skin.

Thanks again, Mark. Solid advice.

Hey, what do you think about increasing the diameter of the fuel line from 5/16" to 3/8"?

I don't see any down-side. Does your engine require more fuel than can be delivered to the carb? If so, then maybe you need a high-flow fuel pump also?

quote:

Originally posted by Mark Charlton:
A high-flow, fine-element fuel filter should be used between the fuel pump and carburetor on the pressure side, not between the tank and the pump on the suction side.

I am wondering if anyone out there can send me a picture of how they attached a filter on the pressure side (as per Mark's suggestion above) while still using the solid line (from the pump to the carb).

I like the sounds of this setup.

You have a solid line running from the fuel pump to the carb? Wow. Mine is a flex hose and the filter is in-line about a foot before the carb, where it's easy(ish) to get at. My rigid fuel line runs from the tank to the pump (unless my memory is even worse than normal... which is very possible after this weekend).

quote:

Originally posted by Mark Charlton:
You have a solid line running from the fuel pump to the carb?

Yep, I believe it's factory stock. Regardless, I will be changing to braided stainless steel with an inlet filter in the same place as yours ...

quote:

My rigid fuel line runs from the tank to the pump (unless my memory is even worse than normal... which is very possible after this weekend).

Mark,
Do not feel bad,I have many "old age" moments. You just live with them, and from what I hear the older you get the less you care about what you forgot !

What are we talking about ????????????

Oh yeah, my original solid line was from the pump to the carb.

Well, my gas tank is now clean and she still isn't running. I think I've narrowed this down to a bad fuel pump or the sending unit itself. I'm hoping it's the former as that would be way easier to deal with ...

A few other items I noticed ...

- I removed my carb inlet lines and did another pump test and (this time) there's not a lot of fuel being sent to the carb. This leads me to believe the pump has gone down.

- Despite NOT having an inlet fuel filter, the small filters inside my carb inlets are not there. Not a major deal, but I was a little surprised.

My inlet lines will now be replaced along with the fuel pump. I will also add the inlet fuel filter at this stage.

quote:

Originally posted by Pantera 4134:
Mark,
Do not feel bad,I have many "old age" moments. You just live with them, and from what I hear the older you get the less you care about what you forgot !

What are we talking about ????????????

Oh yeah, my original solid line was from the pump to the carb.

Gee, I guess I'm going to have to change my avatar descriptor to "Old enough to know better and can't remember anyway".

Hey, it was last year when I changed my pump. I can't be expected to remember everything! At least I know enough to qualify that which I'm unsure of (which is pretty much everything these days).

Good luck Erik. My money is on the fuel pump. The sender should not have any effect on the car running, just whether you think you have gas or not.

Well, I'm back up and running (and she's jumping quite nicely, I might add ) so I thought I should close off this topic with a review of what got me back on the road ...

First off, it wasn't my pump. But, after buying a new high flow Holley fuel pump and new braided lines, I replaced the whole system as this was in the plans for the off-season anyway. Good news is that I have an extra pump in storage for any of my local Pantera buddies who may need one. Never hurts to have parts on hand ...

My next step was to blow air into my tank (through the banjo fitting) ... and this proved to be very effective. I could actually hear some sludge forced back through the tank's feeder line and then a little "pop" before hearing the glorious sounds of bubbles in the tank. There's still some shit in my tank - and it will be there until I can get the tank out and serviced in the off-season - so I rigged up a filter on the vacuum line ... one that could be removed to bow out the feeder line again (if need be ) ...

A few pix will now follow to illustrate the "old versus new" of my new fuel intake system ...

Pressure Fuel Line - Old and New

Inlet Connectors - Old and New ...

New Pressure Line ...

Although I REALLY wanted to install the line in this manner - with the new inlet filter displayed proudly above the distributor - this configuration is just too dangerous (think Bick Lighter waiting to happen) so the filter is now down near the pump ...