How To: B5.5 FM100 5-micron Fuel Filter Upgrade

daedalus said:

If I understand correctly -- you did not extend the original hoses at all; just used opposing sides of the filter head ports and there is enough slack to raise the filter high enough? If so, that is the clear winner.

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I installed a new feed hose from the firewall plumbing (hard pipe) all the way to the front filter input port on the FM100 head. I left slack in it to be able to lift the filter out of the clamp and change it without disconnecting either hose from the filter head.

The new hose slack drapes through the area bellow the filter head. I used "marine" quality fuel hose which is bio-safe. It has a thick wall and is not very flexible. While it is not as pretty and clean as the above method, I can change a filter in no time.

aja8888 said:

I installed a new feed hose from the firewall plumbing (hard pipe) all the way to the front filter input port on the FM100 head. I left slack in it to be able to lift the filter out of the clamp and change it without disconnecting either hose from the filter head.

The new hose slack drapes through the area bellow the filter head. I used "marine" quality fuel hose which is bio-safe. It has a thick wall and is not very flexible. While it is not as pretty and clean as the above method, I can change a filter in no time.

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Sorry - I mentally combined the two configurations. I think I will go with the original hoses on opposite sides of the head. I can always use my hose clamp pliers thingies to close off a line whenever I need to change the filter.

One question remains: why saw off the mounting flange? Is it in the way or does removing it satisfy a need for look and feel?

daedalus said:

One question remains: why saw off the mounting flange? Is it in the way or does removing it satisfy a need for look and feel?

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It looks cleaner without it.

daedalus said:

If I understand correctly -- you did not extend the original hoses at all; just used opposing sides of the filter head ports

Click to expand...

Correct.

daedalus said:

and there is enough slack to raise the filter high enough? If so, that is the clear winner.

Click to expand...

No...there is insufficient slack in the un-extended stock hoses...one will have to be removed to change the filter. There isn't enough space on the firewall side for extending the hose. It would likely kink and restrict flow.

Thanks to all for the guidance. I installed the FM100 with the short filter and the 100 Watt top load filter this afternoon. It was a piece of cake! By the way, Grainger has the 3/8" NPT to 5/16" hose barb adapter making for a neat installation.

To be honest, I didn't take a hacksaw to the mounting ears or connect the heater to switched +12VDC. The ears will probably come off eventually, but I want to leave my options open for now. The heater requires a +12VDC switched supply. I have to try to find one under the hood as I'd rather not go through the firewall if I don't have to. I'm certain I can pick it up from the area of relay 219, but I really don't want to put a hole in the sealed box. Does anybody know of a switched source before I go digging?

Stanadyne also makes a 2micron filter #35612- full flow. Is there a reason why the 5 micron would be preferred to the 2 micron?

truman said:

Stanadyne also makes a 2micron filter #35612- full flow. Is there a reason why the 5 micron would be preferred to the 2 micron?

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I believe when I did the filter upgrade two years ago, a 2 micron filter was not available, only the 5 micron. I would prefer the 2 micron and will order a couple before next filter change.

This sounds great. I'm curious, though.. With these fine-grain filters, they will trap far more particles. Would they exhaust their surface area much more quickly and require more frequent replacement? I'm thinking of the 6" 5-micron or 2-micron. Could they still be changed every 20,000 miles without incident?

mikeclub said:

This sounds great. I'm curious, though.. With these fine-grain filters, they will trap far more particles. Would they exhaust their surface area much more quickly and require more frequent replacement? I'm thinking of the 6" 5-micron or 2-micron. Could they still be changed every 20,000 miles without incident?

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I suspect they do. I have the 5 micron filter installed. The car started idling very rough after ~7500 miles. After checking a lot of possible causes I replaced the fuel filter element. The car was once again idling smoothly.

This is only the first time I have changed the filter so we will have to watch it and see if the problem returns.

Off the shelf

I hate to pi$$ in anyone's Cheerios but I just found this thread and did a little searching online to see about the possibility of finding an industrial replacement thermostatic tee that would work with the upgraded filter assembly, since I live in CT, and found this: http://www.lubricationspecialist.com/volkswagen-tdi/cat-2-micron-filter-system/ and also the instalation instructions that were posted here: http://pics2.tdiclub.com/video/cincitdi/pdf/catinstall_sm.pdf (on the tdiclub server)
A quick search of the Cat filter part number reveals a 2 micron rating.
I'll be ordering it today.

ctnatureboy said:

I hate to pi$$ in anyone's Cheerios but I just found this thread and did a little searching online to see about the possibility of finding an industrial replacement thermostatic tee that would work with the upgraded filter assembly, since I live in CT, and found this: http://www.lubricationspecialist.com/volkswagen-tdi/cat-2-micron-filter-system/ and also the instalation instructions that were posted here: http://pics2.tdiclub.com/video/cincitdi/pdf/catinstall_sm.pdf (on the tdiclub server)
A quick search of the Cat filter part number reveals a 2 micron rating.
I'll be ordering it today.

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Has anyone installed this on a B5.5 yet?

ctnatureboy said:

I hate to pi$$ in anyone's Cheerios but I just found this thread and did a little searching online to see about the possibility of finding an industrial replacement thermostatic tee that would work with the upgraded filter assembly, since I live in CT, and found this: http://www.lubricationspecialist.com/volkswagen-tdi/cat-2-micron-filter-system/ and also the instalation instructions that were posted here: http://pics2.tdiclub.com/video/cincitdi/pdf/catinstall_sm.pdf (on the tdiclub server)
A quick search of the Cat filter part number reveals a 2 micron rating.
I'll be ordering it today.

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I have one of those in my A4 Golf and it works great there. It was my understanding that it won't fit in the Passat...too tall. Or perhaps it'll fit but without the engine cover. But I'll eat my yellow cheerios if I'm wrong.
The question is...where's that industrial thermostatic Tee you mentioned?

I have a CAT in my B5.0. I had to re-shape the bracket a little bit but it works just fine. I'm sure with similar modifications you could make yours work. I did however get rid of the thermo T because it was allowing air to suck into the filter.

Jon

Biodezl said:

The question is...where's that industrial thermostatic Tee you mentioned?

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Stopped in my tracks and ordered that kit from Lubricationspecialist.com and haven't given it a second thought because the stock thermostatic tee fits the filter head.

Before I found it though, My hopes weren't very high for finding something off the shelf so I was already envisioning buying several VW tee's to harvest the spring and valve assembly out of and SS block tee fittings to machine and fit the stat/valve element into.

I bought the heater head for the Stanadyne filter. No need for the Tee anymore, so far as I know.

Anybody local need six or seven Stanadyne 5-micron filter elements? My TDI is gone (sob!)

thermo T and air into filter

Of the two previous posters 1 got rid of the T because of leaking air and 1 did not. Anyone else using the Lube Specialists and having kept the T ?

I need the temperature help up here.

Cat 2 micron filter system

The thought of a heated fuel filter appeals to me up here in CT. I have had one issue in the past when it has gotten blisteringly frigid for an extended period of time and it always haunts me but at the end of the day, I prefer to keep the car the way it is. The Thermostatic T works and does not leak when maintained with the proper o-rings and adding wiring and modifying anything on the car that cannot be mistaken for and quickly reversed back to stock is not in my interest. I feel that the engine as a whole is a relatively well documented and robust design. If I apply un-engineered modifications, troubleshooting may be hampered in the future.

I chose the lubrication Specialist Cat system because it keeps everything in place with no permanent modifications. Although I never expect to; In a pinch, I can revert to the stock filter if need be. I can attest that the kit shipped very quickly (to satisfy my instant gratification), was complete, and of the highest quality components. I am very satisfied with this solution and highly recommend it to anyone.

My only regret is that I didn't know about the kit 150k miles ago and that the car didn't come with this level of filtration from the factory.

I was wondering if anyone could send me the link to purchase the "lubrication cat specialist" fuel filter or any other 2-5 micron fuel filter that leaves the thermostatic tee intact? Thanks in advance.

My understanding is Lubricationspecialist.com does not sell these kits any more.
If you want to keep the thermostatic "T", your going to have to do some addition machining/modifications to a FM 100 filter head or Nictane filter head.

I've been running the Lubrication Specialist (LS) filter for a few years now, but I am not a fan of replacing the filter. Probably is the reason why I take it to a 35-40 K change interval. The changing the filter in a FM100 very easy comparing to the Nictane and LS counterparts.

Does anyone other than me have concerns using brass fittings? Biodiesel does not like brass if you happen to run it like I do.Who is the best source for the FM100?

i buy my fm100 stuff from thedieselstore, never had a problem with them and good prices.

i love my fm100, i use it on both mk4's and on my mk1 and mk3. i use the 5-micron filters with the clear pre-filter, which thedieselstore also has.

i also have no regrets about not having that pesky thermo-t. you can get a side-load heater for the fm100 if you really feel it helps.

burpod said:

i buy my fm100 stuff from thedieselstore, never had a problem with them and good prices.

i love my fm100, i use it on both mk4's and on my mk1 and mk3. i use the 5-micron filters with the clear pre-filter, which thedieselstore also has.

i also have no regrets about not having that pesky thermo-t. you can get a side-load heater for the fm100 if you really feel it helps.

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I really want to convert. I've been hesitant to eliminate the thermo tee but feel the benefits of better filtration outweigh that loss. Are you limited to Stanadyne 5 micron or are there any 1-2 micron filters that will fit?

stanadyne has 2-micron filters as well, but iirc, the 5-micron supposedly gets 90% filtration @ 2-micron. IMO, the thermo-t is useless. i had my mk4's with the stanadyne and no thermo-t up in northern MN for three FRIGID winters with no issue. and i still have no issues, in any of my cars. my dad (also in MN) has a fm100 in his mk4, no issues. personally, i love this setup.

changing the filter means unclamp the filter (mounted in stock location), pull unit up, unscrew the filter, drain out a few tablespoons into a cup in the odd event there is water, then drain the rest of the filter into the new one, put it on, start car. no priming, no taking fuel lines off, no mess, no futzing with thermo-t, no air bubbles, excellent filtration.

You don't need the thermo T, I've never had issues and I know of others who don't use it either that live in MN

Can confirm, didn't have thermo T through polar vortex BS in MN.

Gelling issues are usually going to prevent starting, which means you won't have anything warm to return to the filter anyway.

sirpuddingfoot said:

Can confirm, didn't have thermo T through polar vortex BS in MN.

Gelling issues are usually going to prevent starting, which means you won't have anything warm to return to the filter anyway.

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That's what I always thought too. If it cold enough to gel the fuel, what good is it to circulate it in the engine compartment? You still have to pull gelled fuel from the tank sometime. Only a heated fuel tank forward wvo sytem would work (of course no actual wvo in my cars). Maybe German gimmickery with this T?

iirc, the mk5 did away with the thermo-t. i think the rationale behind the thermo-t is that extremely cold fuel doesn't combust optimally - typical german over-engineering but i think in reality it doesn't do anything except add an unnecessary failure point and maintenance item.

The dieselstore has th FM100 listed with a 4.3" 5 micron filter. I called them and they didn't have any 6" ones. Is the 6" I've been reading on this thread the OAL of the head and filter or is it the filter itself? If so,anyone got a part number for the 6" filter? The diesel store quoted 31877. Takes about 11" clearance?

6" is what you want, i find it hard to believe they're out of them! maybe they'll have more coming in soon. the total height of the fm100 + 6" filter installed is ~9.75", that is to the bottom of the drain nipple, which is ~1/2" long. they also have a 5.1" filter which is probably acceptable for our needs, but i've never tested one.

Thanks for the help. I am interested in the heated unit, but could not find that option at the dieselstore.com. I saw that it was capable. I think it gets as chilly or chiller here in Montana. We had -30 To -40 multiple days this year and even a -60 wind chill day. I plug her in but if I don't and she sits in the cold(<20f) for multiple days she can be harder to start.