Some of you remeber my post http://dieselplace.com/forum/forum_posts.asp?TID=8512&PN=1 that had to do with the benefit of the Post OEM CAT filter. Well now, things have a taken a turn for the worse. Since a few days after the filter replacement I have had "no starts" due to air in the filter. About 10 pumps on the primer and I am off and running. Here is a list of things I have done, but the situation is getting worse as time progresses, i.e., now the "no start" is at least every 2 days (about 4-8 startups).


1. pulled the filters and cleaned the rubber seals and cleaned the filter heads. 2. Removed both filters and greased the rubber seats. 3. Removed the OEM and replaced the top and bottom o-rings. reinstalled with no grease on seals. 4. Removed both and checked filter cans for cracks or scratches to the seal surface or on the filter head seal face. 5. Noticed this morning the fuel line from the CAT (post filter, pre pump) has some hairline cracks in the outter coating. Not replaced yet.


FYI, my Post OEM CAT filter is mounted on the engine block above the power steering unit. Since mounting the CAT on the engine, there has not been any air issues until I swapped the filters about 2 weeks ago.


BTW, in the middle of last week (after 2-3 "no starts") one of Mr. Goodwrench's finest (neighbor) brought me an "injector cleaner" kit that Chevy is now touting as the best for our injectors. Pour one bottle in the CAT and one bottle in the fuel tank. The Manufacturor's name is MOC, The Professional's Choice. I can't prove it yet because I have not filled up yet, but it seems to run quieter and the MPGs 'seem' to have increased. Perceptions, maybe. Anyone ever heard of this product?


Mitch

Could you be sucking air from around the hand pump?

The CAT filters have no integral center post seal around the threads. Many here have reported on an o-ring, or in my case a hand made gasket from the oem post seal, that fixes the air issues.


I believe that many are getting lucky without such a seal. Just think about how the "clean" fuel can traverse from the "dirty" side, and realize that air is easier to move.


HTH.

I would start by eliminating the additional filter by getting one of these http://www.aquaairind.com/Index/Fittings-Valves/Western/Western-BarbHex.jpg or similiar......





If problem goes away then you will have to trouble shoot the Cat or Permacool head fittings ,barb fittings ,etc one by one ....


If not found that way put the system under pressure ....Then you'll either discover the leak or your getting an air trap situation ...





Mac Edited by: Mackin

Mackin


I have a similar problem as Mitchagain.


How do you put the system under pressure to check for leaks? I installed my new Racor R60 pre OEM engine mounted 2 weeks ago ran fine no problems and all of a sudden the warm weather hits the truck stalls right after start up or fails to start at all. Use bleeder screw, raw fuel comes out don't see any airhttp://www.dieselplace.com/forum/smileys/Confused.gif Had 4 incidents yesterday 2 today. Thinking there may be a leak somewhere??? What do you think?
Edited by: TC Dmax

Plum a pump in ....


Mac

get a vaccum guage from the dealer to install to the test port and route a clear hoes between the filter and the pump look for air bubbler. I have seen the bleed screw or suck air and have seen the tank module fittings
or plastic hosind come lose and as the fuel get lower than the hoses it will suck air.and warranty work done that may have caused the fuel system to be opened.

Thanks for the ideas, guys. My cocern is that the only thing that changed was the 2 filters when all this started. I could only blame the filter seals at first. But now??? Well I am going to change out the o-rings on the 2 bleeders this week end and see what time will tell. After that I am going to check into the hand primer. After that I will disconnect the inlet/outlet of the CAT and connect them together and see if its the CAT head. After that I will do the same with the OEM inlet/outlet (after reconnecting the CAT setup). Not sure I understand how a leak between clean side threaded post on the CAT would allow air in the system, but hey, I have a big collection of o-rings that I can try on it.


Frank Blum, you have any idea where I could get the seals for the pump?


Thanks for any/all suggestions, the frustration is building!


Regards, Mitch

Mitch,


I'd bet my left arm that it's the CAT filter/head. I ran the same trapline when I installed mine for the first time and finally found the post seal at the threads of the filter to be my issue. Many others have done the same.


This is page two of my saga, so read my trials if you want on page one... http://dieselplace.com/forum/forum_posts.asp?TID=3670&KW=post+seal&TPN=2


Good luck... Don't get discouraged with your CAT setup... It's great, but just need some tweaking.

nassdmax, Man I thought only bad sh!t happened to me! Ok, you got my attention. I have an absolute ton of o-rings so, rather than put new o-rings on the bleeder, the next step is the threaded post and keep everything crossed. I have a problem with the "pressurize the system" scenario for the simple fact that we know a vacuum leak has an entirely different troubleshooting scheme than a low pressure leak. Thats not to say I am not willing, just that I am some what dubious of the effort versus results.


BTW "Don't get discouraged with your CAT setup" is not an option! I have proof positive that my secondary CAT is doing a hellova job.


Onward and upward! O-rings in hand and I am out the door!

You don't have leaks, you are pulling a vacuum on the fuel and pulling air out of it. Similar to what we used to do in science class as kides, remember? You would take water at room temp, pull a vacuum against it and it would boil. You have addded a restriction at the end of the fuel line from the engine mounted fuel pump and the harder the pump pulls the fuel, the lower the pressure is on the fuel causing it to boil. Similar to vapor lock. Get a lift pump, install it to pressurize the cat filter. Problem will go away.

hasselbach, Your point is made and its somewhat valid. The issue is not that there is air in the filter, that discussion has been hammered to death for quite some time on this and TDP for the last couple of years. The issue is that it happened on this system after a set of filter replacements. Prior to the filter replacements and after I moved the CAT filter from under the air box to the engine mount (above the power steering pump) I had 13,000 error free miles. BTW I added an o-ring to the threaded filter post this morning, put a zip-lock bag around the filter and head and primed the p!ss out of things. 100% positive that there is no air in the filter now (again). Guess we'll see what the future holds now.

See power and performance thread, but here are my lift pumps that completely eliminate any air in the system now!


http://www.dieselplace.com/forum/uploads/2BD_2fuel_3.jpgEdited by: hasselbach

hasselbach, I am not easily Impressed, but man you have impressed me! I have a need to use my truck in some pretty nasty environments and all that "stuff" hanging under the truck, especially with the glass bottoms is not an option that I am willing to partake. If my truck was strickly a 5er hauler on the 4lanes and 2lanes or strickly a pavement pounder I would certainly entertain "something" like that. As it is, that is too much for me. So I'll spend my time trying to fix what's wrong. Thanks for the idea though. BTW, 7 starts yesterday and no air. Waiting..........

Great news... Keep us updated after you run her hard and shutdown till cold. That is when I found my biggest problems.


I never gave up, and I have a great system for those trying times! I believe...

I have a need to use my truck in some pretty nasty environments and all that "stuff" hanging under the truck, especially with the glass bottoms is not an option that I am willing to partake. If my truck was strickly a 5er hauler on the 4lanes and 2lanes or strickly a pavement pounder I would certainly entertain "something" like that. As it is, that is too much for me.


I could not agree more. Once you take your truck off road and too remote locations, durabillaty and reliabillaty become the main purchasing factors.


There is an inheriant problem with filters that have pumps mounted on top, they are very long. It almost justifies the two part setup. Filter in one location lift pump in another.

Points:


1. I'm running the super long filters (6 inches plus), you can get shorter filters (something like 4 inches) that bring the 'glass above the frame if needed)


2. Easy to design a plate to cover glass portions if needed.


3. They are not glass, but a pretty durable polycarbonate material. Probably a good idea to have a few extras on hand though.


4. I could always cut a hole in the passenger area and built a hump in the floor like chevy did for the Camaro 4th generation passenger side cat (what a big bump)http://www.dieselplace.com/forum/smileys/Approve.gif


5. you don't have to use the glass additions however, they are for water removal only.


6. Works flawless, I have driven 1k miles and my Mega filter is now always full.


Edited by: hasselbach

Hasselbach,


I think you probally have another thread somewhere with your modification? However I will ask you here anyways. What is the current(amprege) draw of those two pumps? What is the output flow measured in GPH? And what is the working pressure under load or W.O.T.?Edited by: Bronco

Ah I think they draw 400 amps and flow about 1000 gallons per hour.


No wait, that's my pool lift pump specs.


Actually, you can find them on the Stanadyne web site. They are FM 100's. They flow 80 gallons per hour at about 6 psi. With one only, I would drop to 1.5 psi when I jumped on the throttle, then it would rise to about 3 psi during the fuel run. Now with 2, the pressure goes from 6 to 4.5, and stays there until I lift (no pun intended).


Truck starts immediately now.


The FAss and Prep unit scared me with the high pressure (something like 15 psi), which I guess you could regulate it lower, but I was concerned that introducing a regulator downstream from the FASS might again introduce bubbles with the pressure drop. I'm going to add a Autometer electric fuel gauge at the mega so I can keep an eye on the pumps. The pumps are easy to bypass by installing a one way valve in the system between the tank and engine that would only become active should both pumps fail (cleaner looking and better than installing a gate valve which requires manual input)


If you want to look closer to the FM 100's, call Reliable Industries at 504-733-4120, ask for Scott. He's pretty knowledgeable on the subject. I think their web site is reliableindustries.com.


Any other questions, PM me. Good luck.Edited by: hasselbach

The FAss and Prep unit scared me with the high pressure (something like 15 psi), which I guess you could regulate it lower, but I was concerned that introducing a regulator downstream from the FASS might again introduce bubbles with the pressure drop.


This is the problem with starting multiple threads and hyjacking threads.. Everything gets all out of order and screwed up.


Anyways both the FASS and Prep each have there own pressure regulator built into the unit. It has a spring that can be trimmed to adjust pressure. However if you buy the right sized unit for the correct application you will not need to alter pressure. Just thought I would add this here so that mis-information was not being spread around.

Well, I'm the first to admit that I don't have either units, and know only about the details on them from Bronco's replies. However, when I read Brad's emails with all of the attached customer satisfaction quotes, I saw many that referenced 15-17 psi outputs, as well as Charlie quoting the same.


If you can throttle them down, so be it, I stand corrected.http://www.dieselplace.com/forum/smileys/Geek.gif

Yeah the Dodge guys like the higher pressure. You can however throttle them down. FYI several here have used upwards of 15 PSI with no adverse affects. I have read that 20 PSI is the max pressure limit for the Dmax. This would also coinsidde with what the Dodge boys are running. There system is very simalar to ours.


I myself was very concerned about excessive pressure in the beggining as well. After a few months of research and debate, I have realised it is not the end of the world. Obviously volume is the prefered method of delivery but you can only fit so much fuel through a 1/2 inch line. A little pressure is required.Edited by: Bronco

I reviewed my old chemistry books from college (majored in engineering) and relearned a few things about vapor points, fuild vs. air etc.. (amazying what you can learn sober).


But from what I read, it makes sense as follows: The bubbles on the high pressure side (25k psi) are probably non existant at that pressure, and actually turn into a fluid. Similar to the introduction of CO2 in sodas (albiet at considerably less pressure, it takes something like 50 psi to turn CO2 from a gas to absorb into a liquid). At 25k PSI, I think any and all gases become liquid.


IMHO, The only possible advantage to having the reduction of gases in the fuel would be on the low side of the pump to prevent cavitation, similar to what happens on the back side of a prop in a boat. I used to race flat bottoms in the 80's, and when we got a bad prop design, the water would boil on the leading edge of the blade and pit the aluminum surface.


Lastly, all fuels have a complex mixture of various hydrocarbons, which depending on vapor points, become airborn at some point, pulling these off is probably not a good idea. In fact, nitro has a very high percentage of oxygen and other light elements which allows it to burn at extremely high BTU's and extremely rich mixtures. I wonder if pulling out these vapors actually lowers the BTU content of the diesel fuel?


PS, I'm sure Two Guys probably did dyno the Prep after install, found no gain, and elected to omit that portion from the show. I bet Charlie didn't get the free press for nothing, most times these sponsoring companies pay big bucks to have their products spun on shows.

Well I really was not trying to go there. I just wanted to point out the fact that they did have pressure regulators. Like I said before, after several months of lolly gagging, independant scientific testing would be the only way to verify or disprove any benifits or downsides to removing air assuming air is really that prevalent. It is a very complicated subject. The one thing is for sure which is in my 4 or 5th. post in the Fass thread. Both units will provied large amounts of water free/ dirt free fuel. Other than that, I have no idea. Edited by: Bronco

Just to keep ya'll updated. 4 days and 23 starts later, old DMAX has not died due to excessive air. Fingers crossed but the o-ring is building my confidence (thanks nassdmax!) More later.

What are O-ring measurements? Sounds like a good move to make on initial install or on filter replacement as a pre-emptive move!

Glad to hear it!!! Just glad that the pain that I and others have suffered has helped another out. Now quit counting starts and just DRIVE IT!!! http://www.dieselplace.com/forum/smileys/Clap.gif http://www.dieselplace.com/forum/smileys/Clap.gif

Dirty old man, Honestly I didn't measure it for size. I had a box of o-rings that has about 500 of different sizes. measured against the tapered area just above the threads of the CAT. Found one that sit in the "sealing" area and was thick enough to be raised above the flat portion of the CAT plate. This convinced me that the o-ring would seal against the head and the filter. I fit the o-ring over the threaded post and then screwed the filter on. Tightened up the filter hand tight, then added about 1/2 to 3/4 of a turn with the webbed wrench. Seems to have fixed the issue. Like nassdmax told me to, I'm just driving it, though I am counting startups under my breath! http://www.dieselplace.com/forum/smileys/Big Smile.gif


Kind reminds me of the old story "for the want of a nail the shoe was lost", how come CAT doesn't put an 0-ring on the filter or the head?

OK, I am officially going to bless the o-ring. No issues since I installed the o-ring on the threaded post. Thanks a bunch nassdmax! 10 days no start & Dies.

Wow, all the kudos... I'm flabbergasted. http://www.dieselplace.com/forum/smileys/Embarrased.gif


It's actually not just my experience but Greg's as well. Just glad I can share... Good to hear your up and running again!

Last post on the subject guys. The o-ring on the threaded post is da final fix. Since the install in the middle of May, not a single failure. Can only figure that the threads on this particular filter must have a flaw. I couldn't see one but as soon as the o-ring was installed, no more "start and die". So, for all you secondary filter users, regardless of brand of head or filter, if you haven't had the "start & die" and after a filter replacement the problem pops up, install an o-ring on the threaded post that seals against the filter. Nassdmax & Greg, you guys rock! http://www.dieselplace.com/forum/smileys/Rock On.gif