Fuel Filter only about 50% full - The 1947 - Present Chevrolet & GMC Truck Message Board Network

semaj4712 · 10-07-2016, 10:01 PM

Quick question. On my wife's 66 c10, she has this inline fuel filter pre pump. It only is ever about 50% full even when running.

I would think it should be more full than this, and obviously, there is an air pocket in it but I cannot seem to get rid of it.

I have done some searching around and cannot find much info on the filter being pre pump like this.

It does not seem to affect the engine idling or giving it gas, we have not driven it yet as this is a rebuilt motor going back in and I still have a laundry list of things to do to get it all finished up.

Warrens69GMC · 10-07-2016, 11:09 PM

See if you can find non-ethanol gasoline. put that in and see if the air pocket goes away. If it does, thats your problem. The ethanol is breaking down and evaporating causing the air pocket.

luvbowties · 10-08-2016, 09:23 AM

I'd guess that is normal. Iirc, the post pump filters do the same thing. Install one and see--I'd want a post pump one anyhow--both = better. If it performs correctly, forget the concern.
Sam

**TJ's Chevy** · 10-08-2016, 10:33 AM

While running, can you see the fuel agitating in the filter indicating that fuel is being pulled? If it's just sitting and idling the high demand for fuel is not there vs at rpm. If you took it for a drive and accelerated hard a few times it would probably fill up.

mehoff400 · 10-08-2016, 01:05 PM

mine was about 50% full once i replaced the gas cap and tightened a few lines its now full

andyh1956 · 10-08-2016, 06:31 PM

It's not air you see but vacuum. If it was on the other side of the pump it would get full. If you put a metal filter on where you can't see it & problem solved!

**jayoldschool** · 10-08-2016, 08:09 PM

Filters go between carb and pump, not between tank and pump (on mechanical systems). The instructions expressly state this for the type of filter you are running.

andyh1956 · 10-08-2016, 08:39 PM

jay is right. But on the other hand my 580K Case backhoe has one of these inline filters right at the tank petcock, then to a primary filter, then the lift pump, then the secondary filter then on to the injection pump. I thought it was a mickey mouse p.o. hack job but there it is in my parts book! Go figure!

**The Rocknrod** · 10-08-2016, 09:33 PM

Quote:

Originally Posted by semaj4712

...
It does not seem to affect the engine idling or giving it gas, ...

Then your golden.

jtrichard · 10-09-2016, 12:13 AM

Quote:

Originally Posted by jayoldschool

Filters go between carb and pump, not between tank and pump (on mechanical systems). The instructions expressly state this for the type of filter you are running.

I call BS .......I have run filters pre-pump for years NEVER had a problem (keeps any crap out of the pump and keeps a HARD line to the carb , to many cars/trucks burn to the ground when someone has cut the hard line and installed an in-line filter with hose and few years later the cheap ass hose that is made today starts spraying gas all over the place and POOF )...... IN 72 ( sure there were other years also) chevy (OEM) ran a frame mounted filter JUST UNDER the cab on C60 with 366

**TJ's Chevy** · 10-09-2016, 12:17 AM

Quote:

Originally Posted by jtrichard

I call BS .......I have run filters pre-pump for years NEVER had a problem (keeps any crap out of the pump and keeps a HARD line to the carb to many cars/trucks burn to the ground when someone has cut the hard line and installed an in-line filter with hose and few years later the cheap ass hose that is made today starts spraying gas all over the place and POOF )...... IN 72 chevy (OEM) ran a frame mounted filter JUST UNDER the cab on C60 with 366

I completely agree, but I think the Jay was meaning with that Type of filter it's not a good idea. With the metal screen filters I've never had an issue running one behind the pump and in front. Never have tried with the paper.

jtrichard · 10-09-2016, 04:31 AM

The frame mounted filter in 72 C60 was a paper filter

THIS is what was used

http://www.2040-parts.com/chevy-gm-o...ebay--i991038/

ImpalaJim · 10-09-2016, 10:47 AM

if it was plugged up dirty it would be full

**TJ's Chevy** · 10-09-2016, 10:52 AM

Quote:

Originally Posted by jtrichard

The frame mounted filter in 72 C60 was a paper filter

THIS is what was used

http://www.2040-parts.com/chevy-gm-o...ebay--i991038/

Just seen one of those in another truck to.

61K10 · 10-09-2016, 01:12 PM

I thank you answered your own question if it runs ok. Rubber hose? been around for years. use good fi rated hose and keep an eye on it.

andyh1956 · 10-09-2016, 08:54 PM

Back to the ORIGINAL question, the Farther the pump has to PULL the fuel, the more EMPTY SPACE will be in that filter. Don't hurt a thing!

jtrichard · 10-09-2016, 09:44 PM

IF the OP took the hose off the fuel pump (with full tank of gas) and hold it straight up then re-hook that should get rid of the air pocket

semaj4712 · 10-11-2016, 05:05 PM

Wow lots of good information, there is a filter post pump as well, but its not see through so I have no idea if there is air in it or not.

But generally I think the main thing to take away is that it is fine.

I did try to unhook it turn it upside down but the airpocket didnt go away.

But im just going to leave it for now until we have any problems. Thanks guys
Posted via Mobile Device

10-07-2016, 10:01 PM	#1
semaj4712 Registered User Join Date: Jul 2013 Location: Los Angeles Posts: 11	Fuel Filter only about 50% full Quick question. On my wife's 66 c10, she has this inline fuel filter pre pump. It only is ever about 50% full even when running. I would think it should be more full than this, and obviously, there is an air pocket in it but I cannot seem to get rid of it. I have done some searching around and cannot find much info on the filter being pre pump like this. It does not seem to affect the engine idling or giving it gas, we have not driven it yet as this is a rebuilt motor going back in and I still have a laundry list of things to do to get it all finished up.

10-07-2016, 11:09 PM	#2
Warrens69GMC Registered User Join Date: Jan 2003 Location: Safford,AZ Posts: 3,613	Re: Fuel Filter only about 50% full See if you can find non-ethanol gasoline. put that in and see if the air pocket goes away. If it does, thats your problem. The ethanol is breaking down and evaporating causing the air pocket.

10-08-2016, 09:23 AM	#3
luvbowties Registered User Join Date: Feb 2009 Location: southeasternfoothillsofusa Posts: 1,557	Re: Fuel Filter only about 50% full I'd guess that is normal. Iirc, the post pump filters do the same thing. Install one and see--I'd want a post pump one anyhow--both = better. If it performs correctly, forget the concern. Sam

10-08-2016, 10:33 AM	#4
TJ's Chevy Post Whore Join Date: Mar 2013 Location: Southern Oregon Posts: 10,384	Re: Fuel Filter only about 50% full While running, can you see the fuel agitating in the filter indicating that fuel is being pulled? If it's just sitting and idling the high demand for fuel is not there vs at rpm. If you took it for a drive and accelerated hard a few times it would probably fill up. __________________ 1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw

10-08-2016, 01:05 PM	#5
mehoff400 Registered User Join Date: Apr 2015 Location: Puyallup WA Posts: 365	Re: Fuel Filter only about 50% full mine was about 50% full once i replaced the gas cap and tightened a few lines its now full __________________ 66 c10 patina 250 T-5 My truck

10-08-2016, 06:31 PM	#6
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: Fuel Filter only about 50% full It's not air you see but vacuum. If it was on the other side of the pump it would get full. If you put a metal filter on where you can't see it & problem solved!

10-08-2016, 08:09 PM	#7
jayoldschool Moderator Join Date: Dec 2012 Location: ON, Canada Posts: 2,156	Re: Fuel Filter only about 50% full Filters go between carb and pump, not between tank and pump (on mechanical systems). The instructions expressly state this for the type of filter you are running.

10-08-2016, 08:39 PM	#8
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: Fuel Filter only about 50% full jay is right. But on the other hand my 580K Case backhoe has one of these inline filters right at the tank petcock, then to a primary filter, then the lift pump, then the secondary filter then on to the injection pump. I thought it was a mickey mouse p.o. hack job but there it is in my parts book! Go figure!

10-09-2016, 04:31 AM	#12
jtrichard Registered User Join Date: Jun 2013 Location: joshua tree ca. Posts: 1,484	Re: Fuel Filter only about 50% full The frame mounted filter in 72 C60 was a paper filter THIS is what was used http://www.2040-parts.com/chevy-gm-o...ebay--i991038/ Last edited by jtrichard; 10-09-2016 at 04:39 AM.

10-09-2016, 10:47 AM	#13
ImpalaJim Registered User Join Date: May 2014 Location: Kewanee IL Posts: 283	Re: Fuel Filter only about 50% full if it was plugged up dirty it would be full

10-09-2016, 01:12 PM	#15
61K10 Registered User Join Date: Feb 2012 Location: pleasant valley--placerville ca Posts: 3,039	Re: Fuel Filter only about 50% full I thank you answered your own question if it runs ok. Rubber hose? been around for years. use good fi rated hose and keep an eye on it. __________________ 1961 chevy K10 my build is------------61K10 build

10-09-2016, 08:54 PM	#16
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: Fuel Filter only about 50% full Back to the ORIGINAL question, the Farther the pump has to PULL the fuel, the more EMPTY SPACE will be in that filter. Don't hurt a thing!

10-09-2016, 09:44 PM	#17
jtrichard Registered User Join Date: Jun 2013 Location: joshua tree ca. Posts: 1,484	Re: Fuel Filter only about 50% full IF the OP took the hose off the fuel pump (with full tank of gas) and hold it straight up then re-hook that should get rid of the air pocket

10-11-2016, 05:05 PM	#18
semaj4712 Registered User Join Date: Jul 2013 Location: Los Angeles Posts: 11	Re: Fuel Filter only about 50% full Wow lots of good information, there is a filter post pump as well, but its not see through so I have no idea if there is air in it or not. But generally I think the main thing to take away is that it is fine. I did try to unhook it turn it upside down but the airpocket didnt go away. But im just going to leave it for now until we have any problems. Thanks guys Posted via Mobile Device



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