MEGA FUEL FILTER

[MIKE WIENER]

Has any one instaled the kennedy mega fillter on a truck with the banks brake? In loking over the instal on the web the mega instals in the same place as my brake's air compreser under the air box.

Also is it realy reqiered to bleed the filter after every fill up? or is it just a some time posabelity?

MIKE

[Kennedy]

This filter head has been specifically designed to mount beneath the air box tray. If you desire, I'm sure you could fab a bracket to mount elsewhere.

Another alternative is to relocate the compressor to the second alternator position, or back by the LH rear corner brace under the hood.

BD has done these in both of the afformentioned locations.

I have a bleed orifice that allows air to pass eliminating the need to bleed the filter.


PS. Be sure to lubricate/inspect the brake cylinder. I've heard of them sticking which can cause MAJOR headaches...

[urcndust]

John, I have your mega filter, and I didn't understand the bleeder screw to eliminate air. Is this something you explain in detail on your web site, or an add on that you sell? Thanks for the information.

[Kennedy]

For those with chronic air entrapment, and no desire to add a lift pump, I have a bleed orifice that is installed internally to allow the air to pass.

[urcndust]

I have never experienced cronic air entrapment or a stall situation yet. I would like to add a lift pump at some time, but I have more things to buy for the truck first.

[MIKE WIENER]

Thanks for the insight. I will be ordering soon. Not related derictly to the filter but when do you think you may have wireing for the lift pumps. Thanks agen

Mike

[Kennedy]

Things have been progressing more slowly than I like in regards to the fuel psi restriction gauge, and lift harness.

I'll have a few more hanresses coming soon hopefully. Problem as of late is the oil psi switch. Sealed connector switches are hard to find...

[HBruns]

I have the Mege Filter installed post-OEM, and no lift pump.

I have never had a no-start, stall condition, or other noticable problem since installing the Mega filter.

However, I have learned that it is a very good idea to bleed the filter on every tank fill. There is enough vapor in the Mega Filter (my assumption is air) to require at least 15 pumps on the fuel primer pump. I notice very little or no air in the OEM filter, which I also bleed. If the vapor keeps accumulating over time and cannot pass through, then I could envision a fuel starvation condition occurring.

I would like to add a lift pump, but $190 for the pump and another $145 ($335 total) for the control harness is a hard sell just to avoid a simple filter bleed.

Thanks,
HBruns

[Idle_Chatter]

I also have the Mega post-oem with no lift pump. Anticipating the potential for some vapor-venting issues, I modified my Mega vent screw with a clear tube and extended it to the top of the radiator housing for better access. I had a few (maybe 3 or 4) start and stalls that required primer pumping - but traced it to my modified vent sucking air! After disassembling and reassembling the clear tube and compression fittings with a bit of RTV silicone, I've been running without issue for 4 months and 7,000 miles now.

[DmaxMaverick]

Having the Mega Filter installed on my '01 now for about 13K, and 3 seasons, have discovered a very important fact (that's fact, not fiction).

The outgassing (entrained air in the fuel that is released under vacuum or high temps) that occurs with the Mega filter is effected mostly by temperature. My guess (not fact) is the fuel viscosity at lower tempuratures increases enough to cause the draw vacuum to outgas the fuel at a much higher rate. It may also be the filter media itself, actually becoming more restrictive at colder temps. 2 microns is pretty small, and it wouldn't take much to decrease the pore size. I suspect that the repeated heating/cooling of the fuel and ambient temps increases the amount of air that occurs.

I would wager (I am a betting man) that if it were tracked, the colder climates/seasons would see more occurances, and less in more moderate/warmer areas. Just the posts in this thread alone leads to that assumption.

My Mega was installed in winter. Initially, I had no air problems. Probably due to a new filter element. After about a month, I bleed the filter just to see what all the hub-bub was about. It took about 40 pumps to get all the air out of the Mega, there was none in the OEM filter, indicating to me that the restriction was at the Mega, not the OEM. A few tanks later, I had a start/stall situation. Bleed the Mega and all was well again. During the winter months and into spring, I've had to bleed about every 3 tankfuls to prevent an embarrassing stall. It takes about 50 pumps. The stalls only occur on a cold, overnight engine. Never when warmed up.

Now that it's warmed up (and how!), no air, no stalls, no problems, as long as I stay near home. I do stay 4 days of the week at high elevation (7000 ft.). The temps there vary from the 30's to 60's. While I'm there, the air returns. Just like before during winter at home. I've hauled several large trailers (8 - 14K) up to there, and notice that I need to bleed the Mega each trip. I guess it's due to the high rate of fuel consumption. The trip is only 15 miles, and elevates 6000 feet. Major grades on that one! Short, but 2nd gear steep. When I pull up the grade, and turn around in the same day, very little air, if any, that I can detect after an overnight sitting at home. At first, I thought it was the higher fuel rate causing the problem. I'm convinced that it may be a contributing factor, but only a small part. The temperature plays a much bigger part.

There is a fuel pump in my future. But for now, the air issue is a mere inconvenience.

[Idle_Chatter]

Interesting theory, DMaxmaverick, but I think the situation is not as black-and-white. I installed mine in Ohio in October, had the series of start and stalls (I recovered from every one by just pumping the OEM primer button about 15 to 20 strokes and firing her back up - did not vent the Mega) in moderate Fall temperatures. After sealing up the vent in November, I had no further incidents (and none to date - knock wood) throughout a pretty cold winter. I was worried about just the opposite - that as temperatures warmed up I might get susceptible. I guess it's just your truck and your luck on air/vapor problems! tongue.gif

[Manfred]

I installed one of the early Mega filter in the "warm" season in SOCAL and my experience correlates to IDLE CHATTER's, just worse. At that time there was a lot of discussion on it, the physics of outgassing play a role. The higher the temperature, the less a fluid can keep gases or vapor in dissolved state. The same applies to it with ambient pressure changes. At a lower ambient pressure in say 7000ft altdude, fluids will allow less dissolved gas(air)in the meduum.

A lift pump is a good idea and will circumvent the problems. I understand that recent Mega filters allow internally some vapour/gas to be passed on through the addition of additional holes drilled in the assembly.

Since I worried to loose warranty by adding a lift pump and know that the single OEM filter is inadequate for US and Mexican fuel cleanliness,
I changed my set-up to a Racor60 in the same location, post OEM. It never required additional priming during it's use.

[DmaxMaverick]

Idle_Chatter

I don't dissagree with you. I'm sure there is more than one contributing factor. When mine stalls, 8-10 pumps on a closed bleeder will get it fired up with no hic-ups. The fuel system is designed to tolerate some air. The problem is when the "bubble" in the filter prevents the draw pump from priming. By just pumping and not bleeding, the problem will return very quickly. All that is happening is you are forcing the fuel past the air. Once the engine is running, it will handle the amount of air that is passing. The bubble in the filter will still be there, and the stall will occur sooner than if you had bled.

There is some backwards logic at play. When the system cools off, the volume of fuel decreases, as should the air. It also becomes more dense. When this happens, the vacuum in the system increases until the fuel cap vents.

My explanation is not absolute, just one contributing factor. Temps will effect the fluid dynamics. Probably moreso on some than others. On a newly installed mega filter, I had no problems, initially, in the winter. It took several thousand miles to show up, and gradually became more frequent. As soon as the ambient temps increased, the air decreased. The air returned as soon as I was in a cold area, then dissappeared in the heat. I'll be doing the traveling to the high country all summer long, so tracking won't be hard.


Manfred

Yes. The high altitude baro pressure does allow outgassing at a higher rate, but the air occurs predictibly the same as at lower altitudes. The system is closed and the relief of pressure/vacuum is regulated by a valve. The altitude should not have much effect. The folks in Denver don't seem to be having more problems than the lowlanders.

My system may be less prone than others, but a wide temp swing has exaggerated the situation enough to make me take notice.

[YZF1R]

FYI, with my MEGA, I also only had problems in winter. I also thought that it was harder to pull the fuel in winter resulting in a gulp of air at start up. Only after sitting over night. The air was always there, just a problem starting cold trying to pull heavier/thicker fuel, more vacuum. It would stretch the air pocket out and before the fuel flowed fast enough...."gulp", stumble and stall. I think too it was ONE of the factors.

BTW, I absolutely LOVE having the KD lift pump and harness. Normal every day driving seems to have a little more go and fuel mileage has been up slightly also. Also starts with a little more vigor. Less entrained air = better injection timing.

Steve

[Idle_Chatter]

No contention intended, DMav, just my observations on my experience. I know that just pumping for a restart doesn't remove the "bubble" in the Mega - but I've always been convinced that our systems have an air tolerance in their design (as evidenced in any stock system's OEM filter at changeout). Not that having to suck air is a good thing. There's definitely a lift pump in my future, too. I've been collecting the pieces and parts for a while now. I've really been trying to see if I have any stalling problems with the post OEM Mega and have been running it without a hiccup for 8 months and 7,000 miles now (knock wood).