Oil fill tube question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mblackburnjr · 06-12-2014, 07:24 AM

I have been looking at lots of original engine pics and noticed some have the fill tube, and some dont. So.....was this a factory option or dealer installed?

geezer#99 · 06-12-2014, 09:09 AM

If you mean the tube by the thermostat, it was factory installed with the motor. It was part of the crankcase ventilation system. Depending on the year of the motor the cap on top was vented or solid. When they went to the pcv on the valve cover and a breather on the other cover around 1967, the oil fill tube was plugged.

**FirstOwner69** · 06-12-2014, 09:40 AM

Are you asking about the tube near the rear of the left valve cover or the tube at the front of the block above the water pump?
I believe geezer is referring to the one at the front of the intake that was used prior to emission controls. I think the one in the valve cover may have been just a 4x4 thing. If not, it was probably added in 71 or 72 to make it easier to add oil. Not sure. My 69 3/4 ton never had either.

Coley · 06-12-2014, 10:18 AM

Or....are you referring to the tall oil filler tube sometimes located on the back port of the drivers side valve cover?
I think this was used when the truck came with a/c. The backstory being the fact that the a/c brackets covered over the normal (front) fill location hole on the passenger side valve cover so they added that tall filler tube on the opposite side.
Correct me if I'm wrong on this guys....
Coley

Bigdav160 · 06-12-2014, 11:01 AM

No idea, however, my '72 4x4 w/AC has the tall extension near the brake booster.

The '67 Corvette in my avatar has the filler tube in the front of the intake and has a PCV in the side of the tube.

bMr · 06-12-2014, 11:05 AM

Original owner of a '72 2wd, 350/TH350, A/C which also has the oil filler tube near the brake booster.

71 super · 06-12-2014, 11:11 AM

The extension was used on both 2wd and 4wd to allow oil to be added with brake booster option in place.

**FirstOwner69** · 06-12-2014, 11:27 AM

As I noted in post 3, my 69 3/4 on 2WD with A/C and power brakes did not have one since new. However, the power brakes were added by the dealer prior to sale. I have looked at a bunch of these trucks in junkyards over the years and don't think I've seen one in a truck prior to 71. I very well could be wrong about the year though. To simplify adding oil when there's a brake booster makes sense, but when did it start?

I did a forum search and didn't find a definitive answer.

seattle gmc · 06-12-2014, 03:20 PM

My 70 k2500 has the tall one by the brake booster.

71 super · 06-12-2014, 04:09 PM

No idea on intro. Def. seen more on 71-72 trucks than any other

mblackburnjr · 06-13-2014, 07:48 AM

Ooops! Guess i should've been more specific. I was refering to the one at back of drivers valve cover, near the booster. Is this an option listed on the spid? The few i've seen have been 71 or 72. So the booster reason makes more sense.

**jocko** · 06-13-2014, 07:58 PM

It is not a SPID option. While there appear to be cases where it was not installed on power brake cars, that seems to be the reasoning. Perhaps it was a new thing in 71 to help resolve the pain of filling with oil once everyone started ordering power brakes in those days. Remember that power brakes really weren't all that common (although available) in earlier trucks, so maybe GM finally got the word that folks were annoyed trying to fill up with oil with the big ol booster in the way - and they didn't get the fix incorporated til 71(?) Anyhoo, not a SPID option. Having said all that - I know of a few 71/2's with pwr brks that didn't have it installed. Always hard to tell what some POs have pulled off and tossed though.

06-12-2014, 07:24 AM	#1
mblackburnjr collector of vintage rust Join Date: Apr 2004 Location: southern ohio Posts: 421	Oil fill tube question I have been looking at lots of original engine pics and noticed some have the fill tube, and some dont. So.....was this a factory option or dealer installed?

06-12-2014, 09:09 AM	#2
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,573	Re: Oil fill tube question If you mean the tube by the thermostat, it was factory installed with the motor. It was part of the crankcase ventilation system. Depending on the year of the motor the cap on top was vented or solid. When they went to the pcv on the valve cover and a breather on the other cover around 1967, the oil fill tube was plugged.

06-12-2014, 09:40 AM	#3
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,844	Re: Oil fill tube question Are you asking about the tube near the rear of the left valve cover or the tube at the front of the block above the water pump? I believe geezer is referring to the one at the front of the intake that was used prior to emission controls. I think the one in the valve cover may have been just a 4x4 thing. If not, it was probably added in 71 or 72 to make it easier to add oil. Not sure. My 69 3/4 ton never had either. Last edited by FirstOwner69; 06-12-2014 at 10:04 AM.

06-12-2014, 10:18 AM	#4
Coley Registered User Join Date: Oct 2011 Location: Victoria, B.C Posts: 3,794	Re: Oil fill tube question Or....are you referring to the tall oil filler tube sometimes located on the back port of the drivers side valve cover? I think this was used when the truck came with a/c. The backstory being the fact that the a/c brackets covered over the normal (front) fill location hole on the passenger side valve cover so they added that tall filler tube on the opposite side. Correct me if I'm wrong on this guys.... Coley __________________ ....for some men, there is experience, skill and effort....for the others...there is visa and UPS LOL 1966 Chevy 1/2 ton (Florida- Red/white) 1972 Chevy 1/2 ton (California- Blue/white) 2005 Chevy Silverado HD2500/Duramax 2000 Dodge Ram 1500

06-12-2014, 11:01 AM	#5
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Oil fill tube question No idea, however, my '72 4x4 w/AC has the tall extension near the brake booster. The '67 Corvette in my avatar has the filler tube in the front of the intake and has a PCV in the side of the tube. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

06-12-2014, 11:05 AM	#6
bMr Registered User Join Date: Aug 2009 Location: Auburn Posts: 78	Re: Oil fill tube question Original owner of a '72 2wd, 350/TH350, A/C which also has the oil filler tube near the brake booster.

06-12-2014, 11:11 AM	#7
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,079	Re: Oil fill tube question The extension was used on both 2wd and 4wd to allow oil to be added with brake booster option in place. __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle

06-12-2014, 11:27 AM	#8
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,844	Re: Oil fill tube question As I noted in post 3, my 69 3/4 on 2WD with A/C and power brakes did not have one since new. However, the power brakes were added by the dealer prior to sale. I have looked at a bunch of these trucks in junkyards over the years and don't think I've seen one in a truck prior to 71. I very well could be wrong about the year though. To simplify adding oil when there's a brake booster makes sense, but when did it start? I did a forum search and didn't find a definitive answer.

06-12-2014, 03:20 PM	#9
seattle gmc Registered User Join Date: Dec 2013 Location: Seattle, WA Posts: 155	Re: Oil fill tube question My 70 k2500 has the tall one by the brake booster. __________________ 1970 GMC K2500 aka MaTeR 2007 Chevy Silverado 1500HD Classic

06-12-2014, 04:09 PM	#10
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,079	Re: Oil fill tube question No idea on intro. Def. seen more on 71-72 trucks than any other __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle

06-13-2014, 07:48 AM	#11
mblackburnjr collector of vintage rust Join Date: Apr 2004 Location: southern ohio Posts: 421	Re: Oil fill tube question Ooops! Guess i should've been more specific. I was refering to the one at back of drivers valve cover, near the booster. Is this an option listed on the spid? The few i've seen have been 71 or 72. So the booster reason makes more sense.

06-13-2014, 07:58 PM	#12
jocko Senior Member Join Date: Oct 2009 Location: Godley, TX Posts: 17,960	Re: Oil fill tube question It is not a SPID option. While there appear to be cases where it was not installed on power brake cars, that seems to be the reasoning. Perhaps it was a new thing in 71 to help resolve the pain of filling with oil once everyone started ordering power brakes in those days. Remember that power brakes really weren't all that common (although available) in earlier trucks, so maybe GM finally got the word that folks were annoyed trying to fill up with oil with the big ol booster in the way - and they didn't get the fix incorporated til 71(?) Anyhoo, not a SPID option. Having said all that - I know of a few 71/2's with pwr brks that didn't have it installed. Always hard to tell what some POs have pulled off and tossed though.



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