Seals for Stanadyne Model 80

[Jgreemo]

In my hunt for an air leak, I checked with the local GM dealer and was told that the seals for the Model 80 fuel filter were no longer available. As the replacement Racor fuel filter unit is $300 plus shipping, does anyone know where I might be able to pick some Model 80 seals up?

Thanks,
Jon

[NH2112]

Which seals are you referring to? I used a standard (hydraulic service) O-ring to fix a leaky pressure switch, and I'm sure they'd work for the heater and WIF sensor as well.

[Jgreemo]

I'm looking for the seals for the drain and airbleed valves, located top and lower side of the housing. The R+R guide mentioned these can go bad and that GM carried replacements, but apparently no more. I'm looking at some O-rings now, but concerned that they will not hold up against diesel for too long.

Thanks,
Jon

[britannic]

There are other options, if you cannot find the seals (even after I fitted new seals to mine, it was still had problems), since the FM80 isn't the best design for easy (and non-messy) filter changing:

I picked up an FM100 on eBay, it was a straight forward upgrade and spares are still readily available. Here's an example auction: FM 100 eBay Auction (http://cgi.ebay.com/ebaymotors/6-5-turbo-diesel-fuel-filter-housing-assy-NOS_W0QQitemZ170046603872QQihZ007QQcategoryZ33660Q QrdZ1QQcmdZViewItem)

NAPA stores also carry remote filter housings that can take your choice of water/fuel separators that can be had for under $100.00.

[Subzilla]

I'm also trying to narrow down a leak on my '86 filter housing. It's difficult to pinpoint where it is as the dribblely nature of the fuel spreads and ends up at the bottom, of course. The FM100 interests me. Brittanic, you said it is a straight forward upgrade. Does that mean it will plug right up to the same connectors? Did you mount yours in the same location? I assume the open end is the "up" end?? I don't have a 6.5 to look at.

Thanks!

[Jgreemo]

That definitely looks to be the way to go. I don't want to get into a bidding war with Subzilla though! I'll put in a bid, but also check the local salvage yards.

Britannic, If you have any wiring diagrams to show how you made the connections, that would be a great help.

Thanks,
Jon

[Subzilla]

Go ahead and bid for this one, Jon. I'll wait for the next one! I would like to hear the answers to our questions, though. Thanks!

[moody]

if the model 80 is the square stock fuel filter that came stock on some of these the seals that were in the ends of the airbleed and water drain valve are no longer needed as the replacment valve has it built in to the end of the valve and they only cost about 5.00$. Just thread the whole new valve in.

Or you are talking about a different filter I can't check as I am again away from home.

[Subzilla]

Yes, we would be referring to the model 80. Where does one obtain these replacement valves? Trying to stick to my philosophy: Try the cheap, simple stuff first.

[moody]

I got mine from the dealership. The parts person may not understand that the valve now has a sealbuilt into the end. they are just a plastic thread in piece. If Irecall they suggest you trim off the seal end for some years in the instruction that commes with the part. The computer thet they looked up the parts on had a good diagram of the filter. if yours has a presure sensor that is there to tell if the filter is pluged that might be your leak source. They nolonger carry that part but you can probably thread and plug the sensor hole.

[moody]

That last message was a bit rushed so....
The new type of valve has a soft end on it that makes the seal redundent.
Just replace the valves and the seals as one new unit. (5.00$ fix)
The most likely and hardest leak to find on the fuel filter is through the fo;ter pressure sensor. This pressure sensor is there to tell you when the filter is blocked. They discontinued this part so there are no replacements avalibe. The removal replacement is a bit tricky but can be done. A "o" ring might be found that will seal.
The optional fix is to remove the sensor completly. Thread (tap?) the hole and run in a short screw with some RTV. A brass washer on the top of the screw hay help with the seal. The electrical part of the sensor can just be disconected.
One warning, if you decide to drill/tap the sensor hole be sure to get all the metal waste out of the hole and the filter before you re-install the filter.This is on the out put end of the fuel filter and runs straight to the IP.
Hope this helps.

[Subzilla]

Great info. I'm cruising by the stealership after work today. Thanks a bunch.

[Subzilla]

Went to the stealership and they want $19.23 plus tax for each of those goodies!! This is nowhere close to $5. He printed out the diagram and parts number list. It's called "fuel filter vent plug" with pn #15535678. Guess I'll check elsewhere. He'd have to order them anyway. I asked about the filter heater/plug just for the fun of it - $100!! Yikes! I despise going to my local GM place as they always want retail plus some. Seems crazy when you get the same stuff over the internet for much cheaper. They don't seem interested in giving any breaks either, even though I've been going there for a dozen years and they basically know me by name. Anyway.....

[DmaxMaverick]

You gotta really watch those dealers. I've caught a few gouging, some accidental, some malicious. What happens is they "play" with the retail prices for "unit price", and "package quantity". If list for the plug is $19.23, my bet is a package quantity of 3, 4, or 5. Some of the parts managers/salesmen don't break down their order pricing. They order parts for $19.23, get 5 of them, then sell them to you for $19.23 each.

Just checked the price with gmpd. Guess I was wrong on this part. GM list is $19.20 (1 ea), and their price is $11.98. For that price, it's worth considering an aftermarket filter setup.

What I started off to say is still true, just not in this case.

[NH2112]

GM is famous for the way its parts will be $5 one day and $25 the next. 5 years ago you could get a 73-87 door for about $130, then overnight they went to over $400.


If my truck had only the Model 80 filter, and it was leaking, I think I'd hit eBay for 2 fuel filters instead of repairing/replacing the Model 80. I installed a Racor 445 on my truck as a secondary filter. I think I paid around $100 for the filter and 1 element from DIS, and $80 for 6 R60S (2-micron, 60gph) elements in an eBay auction. I'm using my old Model 80 filter as the primary filter. If you're running an electric fuel pump (which I recommend), a good place to mount the filters is on the driver's inner fender (just fabricate a simple bracket.)

[moody]

sorry for the price change but mine really were only 4.99 $ CND just under a year ago.

[Jgreemo]

Just ordered a new FM100 setup from reliable industries (www.reliableindustries.com) with WIF and heater, three 6" 5 um filters and a 150 um prefilter (for use in Mexico, otherwise worthless) for $160. I'll mount it in the same location as the current Model 80 and be done with the headache.

Subzilla, if the ebay auction for the used FM100 is still going, it's yours buddy!

Thanks for a good thread guys.

Jon

[Subzilla]

Moody or anyone, is that pressure sensor on the side of the filter housing? How is this mounted into the housing? Screw in or friction? It appears that is where mine is leaking but it is wet on the side and on the back of the housing. I need to clean it off good then drive it. Thanks!

[NH2112]

Are you referring to the Model 80? It's on the back of the filter base. There's a round plastic piece about 1.5" across, with 2 wires coming out of it. Carefully pop it out, and you'll see there's an O-ring stretched around the periphery. Clean the groove in the switch, carefully inspect the switch bore for scoring, and clean up any scratches or scores with 600 grit paper. After cleaning the switch bore, stretch a new small fuel-safe O-ring onto the switch. Off the top of my head I'd say a 3/32" x 3/8" is what fits. Lube the O-ring and the switch bore with STP and carefully pop the switch back into place. The side with the wires should go in last. The switch will go in tight, but if you can't get it in with normal thumb pressure or you notice shavings of rubber coming off, use a smaller O-ring or use more lube.

[moody]

Yes that seems to be the way to fix it. I could not get mine to quite leaking and the sensor was NFG so I removed it tapped the hole and threaded in a small bolt. This was discribed somewhere in the forum.

[Subzilla]

Yes, mine is the model 80. I've got a black plastic piece, not really round but more triangular, on the back held on by 2 tiny screws with wires (parts schematic calls it the heater) AND I've got a smaller black fitting on the driver's side of the housing with 2 wires coming from this. I'm wondering if this is the pressure sensor that has been discontinued. I'll pop it out and make a decision on what to do. Thanks!

[moody]

fuel heater has two wires and is at the top of the filter asembly.
pressure sensor(filter change signal) also has two wires and is a clip mounted cirular piece.
Water sensor , has three or four wires, is mounted with two screws(on back of filter) and projects into the filter.
some filter mounts do not have the pressure sensor.

[Subzilla]

Moody, you're exactly right. I went back and looked at the schematic (so much for my memory) and the heater is on top with the water sensor on the back. The pressure sensor is on the side. Thanks.

[Subzilla]

I finally removed the whole shabang this past weekend and now have the full picture of everything ya'll were describing. Even though the pressure sensor is on the back, the 2 wires protude from the side of the housing - hence, my misunderstanding of the picture. I pulled this sensor and saw the big, cracked, leaky o-ring. Went to Napy, Automoan, Advance Auto, Home Depot, & Lowes and had no success with finding an o-ring this big. I'll hit some hydraulic hose shops this afternoon to continue the search. I would tap and plug the tiny hole but I don't have that equipment. Might be time to upgrade the toolbox. Thanks for all the help.

[NH2112]

I would just get a small O-ring - about 3/8" diameter x 3/32" thickness - and stretch it. Try a hydraulic or machine shop for fuel-rpoof O-rings.

[moody]

If you do tap thehol you will want to make sure you get all metal out waste out of the filter moun before you reinstall it. This spot in the fillter is the last stop before the the injection pump.

good luck.

[Subzilla]

I found the correct o-ring at the local hardware store for a whopping 9 cents. I couldn't resist the deal so I splurged and bought 2 of them. Must be that holiday gift buying spirit in me. They had a wall of o-rings so it was easy to match the exact size. Installed it, drove it, no leaks. Life is good.

[waorth]

I want to replace a FM80 in my 85 CUCV. Right now there's a 6.5TD diesel filter on ebay germany (very rare).
Would this (http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=320064519997&ru=http%3A%2F%2Fsearch.ebay.de%3A80%2Fsearch%2Fsea rch.dll%3Ffrom%3DR40%26satitle%3D320064519997%2509 %26fvi%3D1) this be an upgrade for my system?

Sorry for using this thread.

Walter

[john8662]

Chances are that some of the vendors have these sitting on the shelf.

Not worth the risk of ordering something out of the country (had that problem myself).

One member I know of has been running one of these on his '85 K1500 6.2/6.5 pickup for years. TJ.

Supposedly the connectors were the same. I haven't tried it myself.

You'll want the bracket the normally holds the electrical harness on a 94+ 6.5TD to use to adapt a holder to attach this unit to the firewall. The bracket I'm referring to doesn't normally hold the filter to the intake, but it could be used in another fashon, as in this situation.

J

[waorth]

Thanks John for your tips. I didn't think of the firewall holder so far http://coolsmiley.de/smileys/coolsmiley.de.01.09.0002.gif



Maybe I should have been more detailed in my above post:
I am from germany, thus buying this filter on ebay.de is a national deal for me . . .


Anyway, I will think it over.
No leaks on my current unit and for priming the system after a change I already installed an electric fuel pump.
Besides I have to use my FM80 spare filters (5 ea) first . . .


One last question: So this is not the FM100 filter described earlier in this thread?

Thx again.

Walter

[rdurh]

Went to the stealership and they want $19.23 plus tax for each of those goodies!! This is nowhere close to $5. He printed out the diagram and parts number list. It's called "fuel filter vent plug" with pn #15535678. Guess I'll check elsewhere. He'd have to order them anyway. I asked about the filter heater/plug just for the fun of it - $100!! Yikes! I despise going to my local GM place as they always want retail plus some. Seems crazy when you get the same stuff over the internet for much cheaper. They don't seem interested in giving any breaks either, even though I've been going there for a dozen years and they basically know me by name. Anyway.....

GM Parts Direct (www.gmpartsdirect.com) $11.98

[neo]

Is the hole that is about 3/4" in diameter on the top of the Model 80 supposed to have the heater element? How is that thing held in? Mine has (from the DAPO I presume) a peice of what looks like 1/2" copper tube with a cap soldered on stuffed down in the hole with an o-ring wrapped around it. Noticed it was leaking pretty good, that is how I found out it was a piece of copper tube. Don't ya just wanna kick some DAPO's??? ANy idea where I could get a good image of this stuff? My Haynes manual is about worthless... As always, thanks a bunch.

[Goose]

Reviving old post...

I did a seach and found the info I needed for my leaky fuel filter.
It was the pressure sensor o-ring.
Found at local hardware store for $.042 (1 1/4 x 1 1/8 x 1/16)
Took longer on-line than to do the fix.

thanks