Frustrating leak at fuel filter...

[mdregister]

IN my previous post, I described a fuel leak at my filter mounted on the firewall of my 85 suburban. Tonight, I changed the O-ring behind the vacuum switch . The old O-ring lookedas if it was the culprit, it was very dry and cracked.

After replacing the O-ring, I still have the leak.

When I disassembled the vacuum switch, my old O-ring was lying in the bottom of the well the vacuum switch lies in. My questionis, does the O-ring just lie in there, or does it actually fit around the plastic housing of the vacuum switch?


Thanks, Mike

[NH2112]

It fits in the groove around the body of the vacuum switch.

[mdregister]

thanks,

I missed that bit of info in your reply in my last post. Thanks!

Mike

[Robyn]

Take the filter off the firewall and hurl it into the trash on put on a raycor with a cat secondary and be done with it. Your little 6.2 will be a very happy camper and the pump will live a lot longer. The factory filters rate about a -1 on a scale of 1-10 when it comes to clean fuel. I tossed mine out a long time ago. I just bought a pair of 94 Suburban diesels and they too will get new filters soon.

[mdregister]

Originally posted by Robyn C52:
Take the filter off the firewall and hurl it into the trash on put on a raycor with a cat secondary and be done with it. Your little 6.2 will be a very happy camper and the pump will live a lot longer. The factory filters rate about a -1 on a scale of 1-10 when it comes to clean fuel. I tossed mine out a long time ago. I just bought a pair of 94 Suburban diesels and they too will get new filters soon. I am not object to changing out the filter assembly. What model number of Raycor product do you use.??

Would this one be acceptable??

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7956798786&category=33660


Mike

[ 02-28-2005, 08:14 AM: Message edited by: mdregister ]

[More Power]

GM issued a bulletin sometime in the late 80s - early 90's that recommended you remove the components associated with the restriction switch, and then drill/tap the hole for a screw/sealant. It would appear GM had to deal with this problem on more than a few occasions, and determined the restriction switch was more trouble than it was worth. I modified a Stanadyne model-80 fuel filter base following the GM recommendation. It's a pretty simple and permanent fix....

MP

[mdregister]

You mean the hole in the bottom of the recess the vacuum switch fits into, or the hole in the switch itself?

[More Power]

Yes, remove and toss the switch components, and you'll see a hole about 1/4" in diameter in the aluminum housing. That's the hole you drill/tap/seal.

MP

[ 03-01-2005, 07:05 AM: Message edited by: More Power ]

[NH2112]

There's nothing wrong with the model 80 filter, I wouldn't replace it but would rather use it as a primary with a 2-micron Racor as the secondary. I only had the 1 leak from my model 80 filter after 15 years or so (it had the original flat O-ring), and it was only a 1/2 hour job to replace the O-ring. About 5 years and at least 100K miles later it's still leak-free, and that includes a year or so when the filter assembly was sitting in the bed of the truck it came out of. Granted it's more of a PITA to change than a spin-on filter, but it does its job well.

[mdregister]

OK, I have done several things here to no avail. I replaced the o-ring x2 and the switch still leaked. I then tapped the hole under the switch with a 1/4 x 20 tap and installed a 1/4 x 20 plug. I still have a leak at the plug. I have tried a multitude of different sealers with no luck.

I have no idea why the plug is leaking- it was a good tap, the plug fits nicely etc.

This seemingly simple problem has blossomed into a full-fledged pain in my ass.

If I should replace the model 80 filter with a Racor filtewr, will I be ok running without a water detection probe and heater. The filters have a plasic see-through bowl so I can see the water, and it does not get too cold here.

[BobND]

Drain and remove the filter base. Flush the threads and plug with spray carburetor cleaner, and blow dry with air. Mix up a little JB weld (or equivalent epoxy) and coat the plug threads, and screw it in and allow to cure overnight. End of leak.

[NH2112]

I haven't had an operational fuel heater in 2 years and haven't had a problem yet in the cold we get up here. The lack of a WIF indicator isn't a problem, I just drain the primary every week or so and check the bowl on the secondary at the same time.

[diesel65]

Mdregister,
Did you use a pipe thread tap?
A 1/4x20 is not a pipe thread tap, you will have a very hard time trying to seal the threads because it is a straight thread, pipe tap has a tapered thread to aid in sealing.

[mdregister]

Wow, thanks for the fast replies everyone, I guess the frustration was apparent hehe.

I did not use pipe threads. My tap was a standard 1/4 x 20 tap.

I am going to try the JB WELD route first. If that does not work, I will tap the hole slightly larger with pipe thread and plug it again.

If that fails, I will order a Racor filter system or push the damn thing off the pier. I will decide at the last moment. I will post pics if I decide to push it off the pier. smile.gif

Mike

[mdregister]

Thanks all,

The JB Weld did the trick- no more leak. I also noticed that the "harder" starts I had been experiencing and my occaisional rough idle are gone. Coincidence or was it air getting in from my leak?