911SC fuel filter confusion

[phiba]

What I thought would be a simple job has turned ugly. I wanted to change the fuel filter on my 78 911SC, so I ordered Pt 930 110 076 from our sponsor. According to the catalog, this is supposed to be Bosch 0 450 905 021. What I received was 0 450 905 079.

No worries, they looked just the same, probably just a part number upgrade. So I removed the filter from my car, and it was a 0 450 905 016. According to the online catalog, this is for years 74-77. (It looks very similar to the 079, except that the direction of flow arrow is pointing the opposite direction.)

Again, no worries, I would just remove the fittings from the ends of my 016 filter and screw them into the 079 filter. But the threaded hole on the outlet port is too small for the fitting taken from the 016. I have now ordered that fitting (930 110 199), but it is apparently backordered. I have also purchased a proper 021 filter from another vendor, but it seems identical to the 079.

So my question is this. What is different between all these filters? Could I install a new 016 filter instead of the 079? BTW, when I bought a new 016 filter, it came with the threaded fittings already on it, whereas the 021 and 079 do not have them.

My main reason for changing the filter was a hot start problem seemingly linked to a faulty accumulator, which I am changing at the same time. But now I am wondering if the 016 fuel filter could have been part of the problem.

[khamul02]

I had the same problem. This might help:
Fuel Filter Fitting

[phiba]

Tom, thanks for the link. Comforting to know I'm not the only one. From the gist of it, I should probably just use the 016 filter, since it comes with the fittings. Still, it seems odd that something so simple...For fun I've posted a few photos of the situation...the one attached to the accumulator in the 2nd photo is the old one I removed.

[phiba]

Having thought about it a little more, it occurs to me that mine is an early MY78, actually built in 77. Maybe the 77-style 016 filter was the original...

[911sc79]

I replaced the accumulator and filter today on my 79. The original filter last digits were 021, the one I received from Pelican was 079.

I was luckier than you. Everything fitted perfectly eventough the Bosch number was different.

[suckho]

What is the recommended change interval for fuel filter in 911 SC? I replaced it yesterday and the old one was dated 5/1984 (my car is 1982 model). How about fuel accumulator, is there any need to change it if it works?

Changing fuel filter was easy in theory, but in reality I had some problems with the upper connector. Thanks to this thread I was prepared and managed to use the old connector instead the one I got with the new filter. Since the car had been sitting in the garage over two months, I didn't have much problems with spilling fuel although there was some in the filter.

[FL911SC]

I had the same problem with my '79 and now have a small collection of fuel filters in my garage. (note to self, need to get these posted in classifieds).

[Jdub]

Holy Cats! Your filter is THAT old? I change my fuel filter twice a year - that is a bit extreme I think though, but it was always my method when winter brought on the waxy crap called Ethanol. Once when the Ethanol season was upon us, once when it went away in the Springtime.

You change the fuel filter by putting a bunch of paper towels under the filter, unscrew the upper nut. Remove the cap from the new filter and place that on the now-exposed old filter's upper thread - this causes a vacuum so no fuel comes out when you now unscrew the bottom nut of the filter. Remove old filter, screw in lower nut, then finish at top.

[suckho]

Yeah, that is the theory how it is easily done.. As I said, I had some "minor" problems opening the upper connection and finally had to open lower one first and screw the whole filter out of the upper connection. I also thought that 1984 is pretty old.. ancient I would say.

[OsoMoore]

I had the same adventure with my fuel filter. What I ended up doing was bringing my old filter into a local parts shop and saying "give me one like this."

[mrhaydndownes]

Hey All,

Just went through this myself a couple of months ago.

I have a '80 SC, but when I looked at the filter in the car, it had the part number of the 72 ~ 76 filter.

I actually called our hosts, who recommended that I stay with that filter, as a] you know that the filter would physically fit the connections, and b] the fuel pump pressure and flow was the same for all of the CIS engines.

I took their answers at face value and installed the same filter, because the car runs fine.

In terms of the frequency, there is apparent agreement that for $15 and 15 minutes, why wouldn't you change it at least once a year?

Between potential ethanol issues in the gas causing the filter to clog and the cost of the downstream components [fuel distributor, injectors], it's cheap insurance.

Hope that this help.

[Tidybuoy]

This is just a hunch, but I guessing that the same guy who designed the various Bosch WUR's was moved to the fuel filter department (i.e, vacuum port on top, then on side...)

Originally Posted by phiba

[oildrip]

Reviving an old thread in case it helps someone else.* My 1980 still had the 450 905 016 filter on it when I got the car.* Bosch no longer makes the -016 filter, it's been replaced with 450 905 021.* The problem is the outlet changed from 14mm to 12mm so the original fitting of 14mm male to the 16mm inverted male for the fuel line won't work.* It took me awhile to figure out that you need to order fitting 930-110-199-00-OEM that has the correct 12mm male outlet to 16mm male inverted flare for the fuel line.* You can still use your original inlet fitting off the -016 filter on the -021 filter. Hope this helps someone else.

[scotricker]

Yes ! thanks, that helps me too. I had the Mahle, but then got a Bosch, and then made my own adapt-o-matic fittings to make the 12 to 16 . I'll get the real part thanks,
So, it's not just me that can't figure out why won't this work ! Now I'm all better .