position of fuel filter

Wiltshireboy · Post by **Wiltshireboy** » Mon Feb 21, 2011 2:41 pm

I need to put an in line filter in. Should I put it just before the carb or before the fuel pump?

Post by **wesk** » Mon Feb 21, 2011 2:55 pm

It should be on the inlet side of the fuel pump. However if you have a good military filter in the tank then you shouldn't need to add one in line.

Wiltshireboy · Post by **Wiltshireboy** » Mon Feb 21, 2011 4:54 pm

I have a new intank filter, but very fine rust seems to be getting through. I saw it in the float bowl of the carb. Seems to me that the old style filter is not that good, so thought a modern inline one would do better?

Post by **wesk** » Mon Feb 21, 2011 10:02 pm

That very fine rust could be from the steel tubing. The tank filter should stop any fine rust. It won't hurt to run the second filter.

I hate to see folks just cut the tube and slip the filter in with two pieces of hose. It's better to maintain the integrity of the system and use an 1/8" P nipple between the fuel filter and the fuel pump and then move the 1/8"P nipple with inverted flare tube adapter to the other side of the filter and reconnect the original tube there by just bending the tube a bit to shorten it.
Of course you will need to buy a filter with threaded ports.

Another alternative is to use the WWII MB firewall mounted filter and bracket.

Or buy a CJ3A dual fuel/vac pump with the glass bowl filter built in right on top.

Cacti_Ken · Post by **Cacti_Ken** » Tue Feb 22, 2011 10:19 pm

I put an inline fuel filter on the inlet of the pump. I had to use rubber hose because I could not find the filter with inverted V and or 1/8" pipe threads. If anyone out there has a part number for one please pass it to me. I prefer tubing screw connections over rubber hose.

Post by **wesk** » Wed Feb 23, 2011 12:24 am

There's a pretty good selection of threaded port fuel filters out there.

Hi performance catalogs carry them but most are 3/8" P which is simple to reduce to 1/8" p or adapt 3/8"P to inverted flare.
http://www.jegs.com/webapp/wcs/stores/s ... rect=false

3/8"P inlets

http://www.jegs.com/images/photos/0/037/037-GF652.jpg

Here's an Edelbrock with 1/8" P inlets.

SteveJ · Post by **SteveJ** » Thu Feb 24, 2011 9:11 pm

Ive always used the military filter in the tank. It works good and lasts a long time and Ive never had a fuel delivery problem in the 14 years Ive been running my M38. I find that the inline one especially between the pump and the carb tends to look out of place on the military jeep.

Though those inline ones that Wes has pictured looks pretty slick and it would save digging in the tank to change the filter.

Maintenance schedule says 6 months or 6000 miles and clean the military filter.

Post by **wesk** » Thu Feb 24, 2011 9:58 pm

As I posted in my first post and Steve posted above the military in tank filter system served the jeep well for half a century. If you are getting rust in your carb then the in tank filter system or delivery plumbing has failed and that issue should be addressed instead of placing a downstream band aid on the engine. The existence of the rust itself is a defect that needs to be fixed and not covered up. Perforated fuel pickup plumbing in the tank can take rusty residue from the tank to your carb effectively bypassing the in tank filter.

Wiltshireboy · Post by **Wiltshireboy** » Sun Feb 27, 2011 7:03 am

thanks guys. I will look at this. Andy