87 Carrera Fuel Filter

[rwingnut]

I just went to change the fuel filter on my '87 Carrera and noticed that the filter the shop put in previosly was a Mahle KL22. I just order a new filter (928-110-253-06) and received a KL21. They are the same size and shape except the printing indicates flow in the opposite direction. To align the new filter's flow direction with the old one I would need to swap the male/female fittings. That would also put the crimped end of the filter housing down, opposite of how it is now. Question: In a stock '87 Carrera, should the fuel filter flow direction be up or down? Which is correct KL21 or KL22?

From what I can see of the routing of the fuel lines, the old filter appears to have been mounted with the flow direction backwards.

Thanks

[Por_sha911]

I've got the same filter sitting on my shelf and I've been wondering the same thing.

[Por_sha911]

Bump. I know this isn't as exciting as putting a 3.6 in a `77 or hand forging new wheels from a block of AL but any help would be appreciated.

[sushinav]

Can't help you with forging wheels, and my 87 is in the shop or I'd run out and check it for you. If you don't have an answer by tomorrow I'll check mine. Could try tracing the fuel, remember it will flow toward the engine. Free bump at least.

[Tigerrat]

On my '88 its a KL-21 and it flows UP. Ken

[wente]

my 87 flows up - but it's s knecht, not a mahle
ell

[11budlite]

Does anybody know what the difference between these two filters is? I'm in the process of changing the fuel filter in a 1987 Carrera 3.2 and I have a KL22 in my parts stash. The filter that's on the car presently is a KL21 but when I compared the two externally they look the same. The flow direction arrow is pointing up on both filters. Here's a photo showing the installed KL21 on the left with the KL22 on the right:

[twistoffat]

Was the KL22 not for the Turbo´s and the 21 for the Carrera´s ?

[11budlite]

Originally Posted by twistoffat

Was the KL22 not for the Turbo´s and the 21 for the Carrera´s ?

I think you're correct, but I was wondering what the difference was and if there was any reason why you couldn't use the KL22 on a 3.2 Carrera? Maybe the KL22 has a higher flow rate for the increased fuel requirement on a Turbo? From the application guide for the KL22 it looks like you can use it on "911 Carrera / Turbo (1987-1989)": Pelican Parts - Product Information: 928-110-147-05-M67 I'm assuming from this info I could use it but I just wanted to verify that it'd be ok? I just rec'd my order from our host and didn't purchase a fuel filter because I thought I had the correct replacement already.

[wildcat077]

I replaced the fuel filtrer recently in my 89 3.2 with a KL-21.
Everything was identical to the original Porsche item ,and there are no fuel
issues whatsoever since i installed it..

Cheers !
Phil

[big911fan]

I also have an '89 3.2. The current filter is a Mahle KL21 and the fuel flow is up. The replacement I bought from our host is also a KL21 waiting to be installed.

[redranger]

I have a Bosch filter on my 86 3.2 and the fuel flows up.

[big911fan]

As long as we're talking fuel filters here I might as well ask another question.

When replacing the fuel filter what do most of you guys do about bleeding off the residual fuel pressure in the lines? Does anyone go to the trouble of pulling the fuel pump fuse and disconnecting the battery negative or do you just put a rag around the filter and disconnect the fittings? Just curious.

[schnellfahrer]

I replaced mine yesterday.
I just put a bunch of paper towels around the area.
There was a much bigger mess than I excpected, though.
I managed to get it out of the engine bay without spilling anything except for on the paper towels.
I think there was at least 6-7 oz of fuel in the filter.

[wildcat077]

I just put a rag around the filter,it didn't make a mess at all in my case.
Did it after the car has been sitting for two days,maybe there was less pressure ?

Cheers !
Phil

[beamonk]

pull the pump relay while running and let it pressure down.