[blazerswampthing]

I have the box style fuel filter and I think its allowing air into the lines. It starts great when warm and takes quite a bit to get it to start cold, once running it runs well. Classic symptom of air in lines, problem is that the only thing I can think of is the fuel filter. I have a spare primary and secondary fuel filter assembly from an 82 or 83, would it make sense to just use those instead? I will still verify that is where the air is leaking into the system. Is the spin on filters any better? Would they help prevent leaking? Isnt the filters cheaper than the box filter?

 

[High Sierra 2500]

I like box filters myself. It seems to be personal preference though, some here on this board swear up one side and down the other the box filters are junk but I disagree...

Spin on filters are less likely to leak, I will give you that. Otherwise I see no benefits.

Do verify where it's leaking first. If it's just the filter itself leaking, just replace the filter. If the base is leaking take a look at where - there are o-rings in there that can be replaced.

 

[0lee]

I have a spare primary and secondary fuel filter assembly from an 82 or 83, would it make sense to just use those instead?

The spin-on filters won't leak, and you could install a fuel pressure gauge while you are at it. It's probably not an awful lot of work to do the change.

Is the spin on filters any better?

Well, that somewhat depends on your preference and needs. The spin-on filters won't leak, but they don't have a heater, water sensor and pressure sensor --- that means they are not as likely to cause problems as the model 80. But it also means that you don't have an indication about water in fuel and low fuel pressure, so you need to drain the water separator like every oil change. I don't believe that the fuel heater works: They draw maybe 200W, and that isn't enough to actually heat the fuel, considering the flow rate. Yet the fuel heater may be an advantage for you because it's still possible that it can help prevent a plugged filter, depending on ambient temperatures.

Other than that, I think that multi-stage filtering can provide better filtering than single-stage filtering can: Each filter can be specialized for what it is supposed to do, like having a relatively coarse filter first to get stuff out that would quickly plug a finer filter (like the water separator), than a finer filter to get the remaining stuff out that must not enter the IP (like the fuel filter).

I changed from the model 80 to spin-ons because the model 80 gave me trouble with the WIF light coming on persistently and because it seemed to be somewhat restrictive with the electrical lift pump --- I couldn't find out why the light kept coming on, but I'm guessing that the WIF sensor is broken. Now I'm using the water separator the older models had from stock and a large fuel filter that is rated for 2 microns and will last a long time. That is better filtering than the model 80 can do.

Isnt the filters cheaper than the box filter?

If you buy them from fleetfilter, the 33123 is $10.11, the 33124 is $8.46, the 33136 is $13.23.

But you might be able to find a fuel filter that fits on the base you have and is rated for finer particles ...

 

[Fred482`]

The most likely spot for air to enter the rectangular (Model 80) fuel filter is through the bleed and drain screw seals. They are square-cut seals that sit in the filter housing, below the two plastic screws, one for bleeding air, the other for draining water/fuel.

I use neoprene fuel hose to make the seals. I remove the old seal by first removing the plastic screw (notice the tapered end), then use an o-ring pick to remove the seal.

I cut a piece of fuel hose to approximate length, insert it into the housing, install the screw noting how far the screw goes into the housing until it begins to compress the seal. I remove and adjust the length of the seal until the screw (taper) just compresses the seal about 1/2 turn before it bottoms out the shouldered head against the filter housing. It needs to bottom out to stay tight. It needs to slightly compress the seal to for an air-tight seal. It's very critical in length. The other critical factor is to cut the hose absolutely straight across. I use a hose cutter but an exacto knife or razor blade will work.

It takes a little practice but a seal can be made easily. Once the length is found, I usually make up a few extras for spares, mark them in a plastic bag and keep them for later use. The factory seals are no longer readily available and to prevent downtime, I just make them up as needed. I usually replace mine every couple of years to maintain elasticity and a good, tight seal.

 

[big_jim]

i hate to side track, i have an 82 with spin on filters, where is my water in fuel sensor, the light does come on from time to time

 

[Jodean]

i dont get why anyone would want the box style filter......

Or was i doing something wrong?...... when you pull it doesnt it leak all over the place??

Im very much happy with the 93 style I installed. No mess.

 

[Fred482`]

big jim, the WIF sensors are incoroprated into the fuel tank sender unit. One in each tank on a factory dual tank installation.

Jodean, I like the box type because it's fast and easy, no lines to undo, etc. No you didn't do anything wrong, just didn't know fuel would run all over the place when you removed the filter. I use a towel to catch it because I haven't found a catch container that will "get it all" without the mess you've described. I change them all the time, so I've developed a method that limits the mess.

I hold the filter against the base, release the spring clips, put a towel (big and heavy, very absorbent) under the filter, as I remove it, I tip it up quickly to keep as much in it as possible. Not much leaks out.

Same procedure, performed backwards when installing a new one. I fill it with a quart squirt bottle (like the ones differential lube comes in) and reinstall the filled filter in reverse order. I usually don't get enough air in the system to even cause it to run rough. I've not had to prime or bleed air since I started doing it this way.

Same with the two filter system, fill them to the top before installing and no priming/bleeding necessary.

 

[0lee]

i dont get why anyone would want the box style filter......

I don't want it ...

Or was i doing something wrong?...... when you pull it doesnt it leak all over the place??

Open the bleeder and the drain valves so that the fuel runs out before taking the filter off the base.

Im very much happy with the 93 style I installed. No mess.

Well, if that's the type that is like a cup, with the filter element inserted from the top (very much like or the same as they had in '96), the mess is inside because if you don't empty the cup after removing the filter element and eventually clean out the (bottom of the) cup, you will get unfiltered fuel to the IP, eventually with sediment in it that has been stirred up from the bottom of the cup.

The cup might be easy to clean in your case, but on the '96 Tahoe, it was mounted all the way behind the intake where it was hard to reach. It was impossible to remove the cup (for cleaning) without pulling the intake because you won't be able to get the fuel lines off the cup other than by ripping the cup out in which case you won't be able to get the lines back on. Besides that, the water drain was made so that it was pretty much impossible to catch what would run out when you opened the drain vent. It was a very stupid design.

Did I mention that I like the spin-on filters?

 

[smackzed]

Ok I couldn't link it but it was still alive