Fuel return T-fitting at secondary filter

[bdhansen]

I have tried searching with no luck. What is the function of the fuel return line T-fitting at the secondary filter. I asume it attempts to put fuel into the filter to fill any voids prior to being retuned back to the tank. Wouldn't there have to be a check valve or somthing to prevent reverse flow. My main question is, can I bypass this fitting and have the return just go straight back to the tank, or does it have to tap back into the filters. The reason I would do this is to use an aftermarket filter base. I am going to use the NAPA 4770/Wix 24770 filter base for my primary filter. I see no other reason as to why I could not do the same thing on the primary/final filters. There are a few aftermarket double filter bases out there, or I could just double up the NAPA base. This option is MUCH cheaper than using the many conversion/adapter kits available.

 

[Adrian A]

I am interested in this as well. I was discussing this very thing with my buddy today. My return lines are pinched on the way back to the tank. It seemed to run fine though. Ill be fixing them tomorrow.

 

[gimpyrobb]

That valve is normally closed. It only opens when there is too much pressure in the filter housing.

The PRIMARY filter is under the alt. It filters the fuel on its way to the fuel booster pump on the IP. You will want to put your primary BEFORE the IP, not after it. The secondary filters are bolted to the side of the multifuel motor. You can remove that whole assembly and install whatever you feel like installing. Just in case you didn't know.

 

[Adrian A]

So, you would cap off the return line then if you used aftermarket filters?

 

[Floridianson]

The HH uses the extra fuel flow return to help it stay cool. No matter what you do you will still need a return line to the tank now as for bypassing the finial filter or in this case like Chris said it was used for overpressure of the filter system I would have to read the TM's.


Ok just looked at a TM and it looks like in the beginning they did not run back to the finial so I would say yes forget about the T and just run the return line rigth back to the tank.

 

[bdhansen]

My plan was to replace the primary filter mount with the NAPA 4770 mount and use the same filter/seperator (33405) that the spin on kits use. You can get this mount and filter for around $40. The adapter kits for the primary are $140+. I wanted to do the same thing for the secondary and final filters. I will keep all the filters in the same location, and the plumbing will still be routed the same. I just didnt want to spend $250 for the sec/final filter adapters when there are dual filter mounts/bases on the marekt for around $50 or I could use two 4770 mounts conected in series. I will still have the return run to the tank. But with the aftermarket filter mounts, they don't have the provisions for an over pressure valve. But from what Floridianson said, I should be good to run the return directly to the tank.

 

[m-35tom]

all this is fine, but if you just buy clean fuel you will never need to even check your filters, let alone replace them. 18 years and never a filter change.

 

[eagle4g63]

If you think about the filter process, Tom is partly right....however a lot of people don't put the correct FINAL filter in, they use the same filter in both the secondary and final cans.....the problem with that is almost everyone is using the 10 micron filter...........If you did any checking you will find that the second filter is a 10 micron....HOWEVER the FINAL is a 6 micron filter.......so Back to Toms suggestion, IF you only put "clean fuel in the tank" and there in lies the problem, the fuel you "BUY" at the pump is ONLY filtered to 10 micron.......so if you do put the correct filters and buy fuel you will eventually need to change your filter. The other reason behind the filters is everytime you open your tank you introduce dirt and debris in to the tank....unintentionally, but you still do.....just to put all this into perspective.....did you know that the human red blood cell is between 6-10 micron, you need to magnify it 100 times to make it as big as the tip of a needle........how bid is the junk entering your tank?!?!?

On to the question at hand....bdhansen......if you are going to go with your plan and replace the final filters, make sure 2 things, you don't use a double filter base....they actually only double the flow rate, they do not filter the fluid twice(in one filter then out to the next then out to the line)....second make sure you are using "NON bypass" bases.....they will stop the flow if and when the filter gets plugged up.......the other kind should only be used in oil applications since it is more important to keep a flow and avoid injury to the motor than to keep filtering the product.

 

[JasonS]

Continental talks about this in their manual for the TD427. They caution that without it, pressure could build up causing the filter to break down sending particles into the pump and damaging the pump.