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MG TD TF 1500 - Fuel Filter redux

I spent some time on the archives today reading up on fuel filters. I'm concerned because my MG has had a long history of fuel problems; my father burned through several pumps, and when the tank leaked, used some "miracle" treatment in the tank which made the problem worse, and there's a constant buildup of crud.

It seems the conventional wisdom (expressed by many, including Dave Dubois, certainly an expert in the area) is that there should be no filter between fuel tank and fuel pump, because a restriction could cause the pump to burn out.

Sooo... (heresy follows)

Would not a large, oversize filter (say one designed for an American six or eight cylinder car, intended to handle twice the fuel flow needed by our four cylinder engines) still be a good idea between tank and pump?
My thinking is a) the danger to the pump of a restriction or clog, which causes it to burn out or get damaged, may be no more than equal, or possibly even less than the possible damage to the pump of a constant flow of particles directly into the pump filter, and b) an oversized, inline filter (regularly maintained) would avoid the possibility of restriction.

Think about it for a minute; which is worse, a cavalcade of crud which is caught at the fuel pump filter (where it isn't visible,and will quickly build up and clog, if not cleaned religiously) and which will lead to an inevitable restriction and damage - or a large glass bowl filter easily checked and cleaned, which quickly alerts the vehicle owner to the presence of sediment and the need for cleaning?

It seems to me that so long as the fuel filter is oversized, that a fuel filter between tank and pump is in fact a potential lifesaver for the pump and will help avoid damage to the pump itself, whereas the smaller, hidden filter in the pump should be treated as a "last resort" and protected if possible!

Just my two cents, and I've been known to be wrong - many, many times!

I appreciate everyone's input - especially Dave's!
Geoffrey M Baker

Geoffrey -

I like the look of vintage glass bowl fuel filters. I have a vintage Durex Moraine on my '54 Chevy pickup and it looks (and works) great.

I have looked at glass bowl filters for my TF, but most will not be easy to mount on our carb set up. However, a Rover or Jaguar filter seems like it would be perfect. It mounts to the firewall and the in/out ports could easily connect to flexible fuel lines, and it could be justified as period correct.

They originally had a stone or porous metal filter element. Disposable paper elements are available.

They are frequently on ebay. Search for "glass bowl filter" or "Rover glass bowl filter" or "Jaguar glass bowl filter." They were made by AC. A seller from out of the country usually has new ones for sale. I would rather buy from an in-country seller.

Here is a pic of one without the filter element from ebay ...
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/$(KGrHqF,!hUFDU8r3tbYBQ2sRj7MWw~~60_57.JPG

Disclaimer - I don't have one because I am reluctant to drill holes in my firewall. So I use an ugly plastic NAPA filter before the carbs to catch the crud from an old tank lining.

Lonnie
TF7211
LM Cook

Geoffrey - The filter screens in the tank and the pump are rather course, meant to stop rocks and small birds, whereas today's filters are usually sub micron elements that are there to stop the very fine sediments and very fine rust particles and will clog up rather quickly if your tank has a lot of junk in it along with fine rust particles. When this happens, the pump overheats and will eventually burn out the swamping resistor, which is the only arc suppression circuit in the early, low pressure pumps. When the swamping resistor is burned out, the points start arcing excessively, which greatly reduces the life time of the points.

It really sound like you have a lot of junk in your fuel tank. I think that it is time that you take a look inside your fuel tank, particularly at the filter screen on the outlet from the tank. If you don't have a load of crap in the tank, you won't get a load of crap going through the fuel pump. If the tank is full of particles and/or fine rust particles, your first order of business is to get the tank cleaned out and sealed. Once that is done, you can quit worrying about what kind of a filter you need - you will have fixed the problem rather than the symptoms. Cheers - Dave
David DuBois

I have been doing expediton work with Zodiac RIBs in the arctic , where engine trouble in an outboard engine is always potentially life threatening, and fuel supplies are sometimes dodgy. Standard procedure there is to use a cartridge filter the size of a car oil filter between tank and pump/engine. Works well, and has a huge capacity for crud collection.

Removing and chemically stripping the tank on a T is on the other hand a fairly straight forward winter job.

regards,

Jan
Jan Emil Kristoffersen

Can someone please explain to me why a large cartridge type fuel filter (eg CAV) as installed on the suction side of the fuel supply to an outboard motor would not function on the suction side of an SU fuel pump.

I realize there would be issues mounting and servicing the filter however I struggle with the concept that the SU fuel pump functionality may become compromised.

Appreciate any advice.
G Evans

Dave is absolutely right about fixing the disease not the symptoms. That being said I put a small filter at the bottom of the fuel tank. It is highly visible and easy to clean or replace. That is crud that is not at the hidden filter in the fuel pump. It's been there several years and this is today's photo.
Mort

Mort 50 TD (Mobius)

When I purchased my TD, in 1965 it had an aftermarket filter installed. I believe its similar to the ones Lonnie is talking about.

Mine is made by Carter.
I agree that plugging up the filter could starve the SU pump. However I ran this for 3 years in the 60's without problem. The filter has a glass bowel, up front where sediment collection is quite visible and you are very likely to notice an issue before it happens.

The element is a sintered ceramic so it is not a micro filter.
I do an eBay search daily to look for spare filters and rubber gaskets. They are available, as is the whole assembly.

A picture is attached. I do plan on adding a bracket attached to the starter cable bracket bolt so no additional holes will need to be drilled.

However the car ran for three years without the bracket.

JA Benjamin

OK, now I feel pretty dumb. Look at the image. Yes, it's a fuel filter. JA Benjamin's image made me realize that fuel line looked different - and had an extra bracket that his didn't. What I had assumed to be just a union turns out to be a fuel filter.

Geoffrey M Baker

Here's the filter turned up and opened.

Geoffrey M Baker

Here are the parts of the filter

Geoffrey M Baker

And here's the crud I cleaned out of it this morning.

Geoffrey M Baker

This thread was discussed on 17/04/2014

MG TD TF 1500 index

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