Need help locating an obsolete part - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kazoocruiser · 09-25-2018, 12:27 PM

The truck is a 1981 C10 Scottsdale longbed with a 250 inline 6 with the integrated head.

The switch I need screws into the oil galley on the passenger side of the motor, about 4-6 inches to the right of the oil pressure switch.

It is a 2-port switch, which allows manifold vacuum to flow to the heater stove actuator, until oil temperature reaches 150 degrees F. It is called a EFE valve or switch.

The part number I pulled from the service manual is 866887. CORRECTION 366887 Thanks ElGracho.

Thanks in advance for the help.

83GMCK2500 · 09-25-2018, 05:28 PM

Napa calls it a Ported Vacuum Switch, still available. If you know the temp rating that may help your search.

https://www.napaonline.com/en/search...=nol-veh-conds

kazoocruiser · 09-25-2018, 09:15 PM

Thank you for the reply, however, the switches showing on the NAPA website mount in the water jacket, probably on the thermostat housing, so they are too big to screw into the hole in the oil galley. I'd prefer to go back with what is coming out if I can.

ElGracho · 09-25-2018, 10:13 PM

Are you sure it isn't 366887?

http://www.gmpartswiki.com/getpage?pageid=59361

kazoocruiser · 09-25-2018, 10:45 PM

ElGracho thanks for correcting my typo. I fumble fingered it from a three to an 8, so yes, it is 366887.

Seems GM used a number i am having no success finding.

83GMCK2500 · 09-26-2018, 10:29 AM

Interesting, what size thread is the switch you're looking for?

I see on this search: https://www.gmpartsgiant.com/parts/g...ch-366887.html that it notes the original P/N was superseded to 12388891. Looking for that number also leads to "discontinued" however there is one on ebay, the appearance is different from original, but the function may be the same...does this look like it is the correct thread dia? The one on ebay: https://www.ebay.com/itm/212-354-AC-...kAAOSwNxlbNVtQ

kazoocruiser · 09-26-2018, 02:55 PM

Hi 83GMCK 2500,

I just sent a message to the seller of the switch on Ebay you sent me the link for, to see if he could put a wrench across the flats of what he has to see if it is the same size as what is in there now.

I don't know what the thread pitch is on what I have, but I am pretty sure, because what I have now is 3/4" across the flats, that if I get something with 7/8" across the flats, that I am going to have to either use an adapter, or try to use the thermostat housing.

Thanks for the detailed help. The difference between a normal ported vacuum switch, which is normally closed until a certain temperature is reached, and what I need, which is an EFE, is that an EFE switch passes vacuum until a certain temperature is reached, when the vacuum is then shut off.

kazoocruiser · 09-26-2018, 03:18 PM

I just went to gmpartswiki.com and entered in 12388891. No results!

Irish1941 · 09-26-2018, 03:46 PM

Quote:

Originally Posted by kazoocruiser

I just went to gmpartswiki.com and entered in 12388891. No results!

Because that part number is too new. It replaced 366887 in 2002.

The one on eBay is correct but if you're still not sure I can look thru my junk and see if I have one in the 366887 box for comparison.
It was used on ALOT of GMs. Shouldn't be too hard to find one.

ElGracho · 09-26-2018, 09:54 PM

I have no knowledge of this company, but I found this one based on the interchange to an acdelco number from the ebay ad above:

https://www.stockwiseauto.com/acdelc...-vacuum-switch

Never mind, I missed the zero in stock...

If you search the ac delco number of 212-354 there are 3 on ebay...

kazoocruiser · 09-27-2018, 01:11 AM

Now that it looks like a replacement switch might be available, my next project is definitely making sure the one I have is bad. Anyone have any advice before I break an egg I can't unbreak?

Maybe I should take a poll.
1. Abandon the switch where it is, and relocate a new switch to the water jacket.

2. Restore operation to original location.

kazoocruiser · 10-21-2018, 12:33 AM

Here's an update. Things can change in a month. I got an offset crowfoot line-wrench wrench (Snap-on, no less) off Ebay to remove the old switch, and then the wrench went missing before I could pull the original switch, In the interim, I ordered another wrench off of Ebay (another Snap-on unit, that is now in transit from Texas). I did a search under the original part number on Ebay, and now there are TEN of these switches available as N.O.S. parts from someone I have bought from before. So things seem to be moving towards a good conclusion. I think EVERY 4.1 250ci I6 motor used this same switch.

09-25-2018, 12:27 PM	#1
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Need help locating an obsolete part The truck is a 1981 C10 Scottsdale longbed with a 250 inline 6 with the integrated head. The switch I need screws into the oil galley on the passenger side of the motor, about 4-6 inches to the right of the oil pressure switch. It is a 2-port switch, which allows manifold vacuum to flow to the heater stove actuator, until oil temperature reaches 150 degrees F. It is called a EFE valve or switch. The part number I pulled from the service manual is 866887. CORRECTION 366887 Thanks ElGracho. Thanks in advance for the help. Last edited by kazoocruiser; 09-25-2018 at 11:07 PM.

09-25-2018, 05:28 PM	#2
83GMCK2500 Registered User Join Date: Sep 2009 Location: Beaverton, OR from WA State Posts: 1,515	Re: Need help locating an obsolete part Napa calls it a Ported Vacuum Switch, still available. If you know the temp rating that may help your search. https://www.napaonline.com/en/search...=nol-veh-conds __________________ Devin 1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt 1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050 1997 GMC Sierra SLT 1500 4x4, Z71/F44, EC/SB, Vortec 350 My Introduction with my '83s History New Daily, the '96

09-25-2018, 09:15 PM	#3
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part Thank you for the reply, however, the switches showing on the NAPA website mount in the water jacket, probably on the thermostat housing, so they are too big to screw into the hole in the oil galley. I'd prefer to go back with what is coming out if I can.

09-25-2018, 10:13 PM	#4
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,550	Re: Need help locating an obsolete part Are you sure it isn't 366887? http://www.gmpartswiki.com/getpage?pageid=59361 __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

09-25-2018, 10:45 PM	#5
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part ElGracho thanks for correcting my typo. I fumble fingered it from a three to an 8, so yes, it is 366887. Seems GM used a number i am having no success finding. Last edited by kazoocruiser; 09-25-2018 at 11:23 PM.

09-26-2018, 10:29 AM	#6
83GMCK2500 Registered User Join Date: Sep 2009 Location: Beaverton, OR from WA State Posts: 1,515	Re: Need help locating an obsolete part Interesting, what size thread is the switch you're looking for? I see on this search: https://www.gmpartsgiant.com/parts/g...ch-366887.html that it notes the original P/N was superseded to 12388891. Looking for that number also leads to "discontinued" however there is one on ebay, the appearance is different from original, but the function may be the same...does this look like it is the correct thread dia? The one on ebay: https://www.ebay.com/itm/212-354-AC-...kAAOSwNxlbNVtQ __________________ Devin 1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt 1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050 1997 GMC Sierra SLT 1500 4x4, Z71/F44, EC/SB, Vortec 350 My Introduction with my '83s History New Daily, the '96

09-26-2018, 02:55 PM	#7
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part Hi 83GMCK 2500, I just sent a message to the seller of the switch on Ebay you sent me the link for, to see if he could put a wrench across the flats of what he has to see if it is the same size as what is in there now. I don't know what the thread pitch is on what I have, but I am pretty sure, because what I have now is 3/4" across the flats, that if I get something with 7/8" across the flats, that I am going to have to either use an adapter, or try to use the thermostat housing. Thanks for the detailed help. The difference between a normal ported vacuum switch, which is normally closed until a certain temperature is reached, and what I need, which is an EFE, is that an EFE switch passes vacuum until a certain temperature is reached, when the vacuum is then shut off.

09-26-2018, 03:18 PM	#8
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part I just went to gmpartswiki.com and entered in 12388891. No results!

09-26-2018, 09:54 PM	#10
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,550	Re: Need help locating an obsolete part I have no knowledge of this company, but I found this one based on the interchange to an acdelco number from the ebay ad above: https://www.stockwiseauto.com/acdelc...-vacuum-switch Never mind, I missed the zero in stock... If you search the ac delco number of 212-354 there are 3 on ebay... __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed Last edited by ElGracho; 09-26-2018 at 09:57 PM. Reason: Messed up.

09-27-2018, 01:11 AM	#11
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part Now that it looks like a replacement switch might be available, my next project is definitely making sure the one I have is bad. Anyone have any advice before I break an egg I can't unbreak? Maybe I should take a poll. 1. Abandon the switch where it is, and relocate a new switch to the water jacket. 2. Restore operation to original location.

10-21-2018, 12:33 AM	#12
kazoocruiser Registered User Join Date: Aug 2018 Location: Bronx, NY Posts: 215	Re: Need help locating an obsolete part Here's an update. Things can change in a month. I got an offset crowfoot line-wrench wrench (Snap-on, no less) off Ebay to remove the old switch, and then the wrench went missing before I could pull the original switch, In the interim, I ordered another wrench off of Ebay (another Snap-on unit, that is now in transit from Texas). I did a search under the original part number on Ebay, and now there are TEN of these switches available as N.O.S. parts from someone I have bought from before. So things seem to be moving towards a good conclusion. I think EVERY 4.1 250ci I6 motor used this same switch.



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