63/64 HP fuel filter assembly

[Alan D.]

The fuel filter for 63/64 HP motors, L76-84, have a number of parts, some common and some different. Summation of parts;

Yr ......Filter ......Bracket .....Screw .....Washer ......Nut

63 ....5650703 ...3834122 ...3778013 ...120394 ...124829
64 ...... “ .............."...... ...3840344....... “ .............“

The washer is common to all however the JG, I believe, has an error relative to the washer.
The 63AIM lists the part (120394) as a L. Washer, a review of the Group 8.929 shows that part to be a Flat Washer. The misconception in the JG that said washer was a “lock washer” in 63 appears to have come from the incorrect note of the 63AIM.

Further the JG calls for a star washer in 64 – why, I have no idea on that one!

I have also found the same washer, 120394, used on the exhaust stud to hold the air intake pipe assy on the L84 (FI) in 64 which lists said washer again as a L.Washer.
However when listed for use with the fuel filter bracket in Sec L75 its called out as a WASHER!

Reference pages in 63/64 AIM used are;
63 Sec L75/76 sheet 3.00 Rel date 11/23/62
63 Sec L84 sheet 5.00 Redraw date 9/4/62
64 Sec L75 sheet 1.00 Rel date 11/23/62
*
64 Sec L84 sheet 2.00 Redraw date 10/10/63
64 Sec L84 sheet 5.00 Redraw date 10/8/63

Fortunately I have owned my car since Aug 1967 at the 30K mile mark. An inspection of the chrome bracket shows no indications of any marks from a lock or star washer. Such lack of damage lead me to look at these parts in the first place.

Clearly from GM documentation thus far the washer used in 63 & 64 was the same part, 120394, and is a flat washer.

Anyone have part prints of any of these ???
* NOTE; the bracket was the same missed a page in the 64AIM, Sec L76 sheet 4.00 redraw dated 3-9-63
However 63 may have had an earlier version, the 63 guys will know better.

[Edward J.]

Re: 63/64 HP fuel filter assembly

Alan, It sure sounds feasible for use of a flat washer, if you were to use a lock washer, when removing the nut it would be possible to loosen the stud with the nut making for a tough filter or bracket replacement, Or even damging the filter bracket

[Doug L.]

Re: 63/64 HP fuel filter assembly

Hi Alan,
MY JG seems to differ from yours or I have not found the location you are looking at. The sheet in my latest edition JG that shows the L-84 fuel filter says to refer to the L-79 sheet. In looking for that sheet I found a list of "non-illustrated parts". Within that list for L-79 and L-84 it shows the part numbers you reference with the exception of the "screw". The only screw listed in that area is the clamping screw that passes from one side of the bracket to the other and clamps the filter in the bracket. My JG shows it as 3840344, not 3840314. The description of the "washer" is only that, "washer". There is no iindication of "L" or "toothed" (star). That washer is used on the stud that is threaded into the adaptor plate. The fuel filter bracket fits onto that stud and is secured with the washer (I installed a flat washer because that is what was there at the time of disassembly) and the nut.

Doug

[Alan D.]

Re: 63/64 HP fuel filter assembly

Right you are on the screw, its 3840344 - been corrected now.

Believe we are both talking about the Assembly Instruction Manual, ie AIM for 1964. When I use "JG" that's the 63-64 Corvette Technical Information Manual and Jugging Guide, ie JG My impression has been that a Judge will follow the AIM if a conflict is found between the two. (??)

So the argument goes as follows;
Sec L84s5.00 says "for fuel filter installations see RPO L-76" and also Sec L84s2.00 says "same as RPO L-76" ->
Sec L76s4.00 says "bracket- attaching parts are the same an assemble same as RPO L75" ->
Sec L75s1.00 shows "view A" which lists the parts and for part 120394 it is listed as a WASHER.

The conflict in the JG for 1964 L76/84 is that it calls for a "star washer", see page 98 just above 10.
So yes Doug we both agree its a flat washer!

[Michael H.]

Re: 63/64 HP fuel filter assembly

The fuel filter for 63/64 HP motors, L76-84, have a number of parts, some common and some different. Summation of parts;

Yr ......Filter ......Bracket .....Screw .....Washer ......Nut

63 ....5650703 ...3834122 ...3778013 ...120394 ...124829
64 ...... “ .............."...... ...3840344....... “ .............“

The washer is common to all however the JG, I believe, has an error relative to the washer.
The 63AIM lists the part (120394) as a L. Washer, a review of the Group 8.929 shows that part to be a Flat Washer. The misconception in the JG that said washer was a “lock washer” in 63 appears to have come from the incorrect note of the 63AIM.

Further the JG calls for a star washer in 64 – why, I have no idea on that one!

I have also found the same washer, 120394, used on the exhaust stud to hold the air intake pipe assy on the L84 (FI) in 64 which lists said washer again as a L.Washer.
However when listed for use with the fuel filter bracket in Sec L75 its called out as a WASHER!

.

Alan,

You are absolutely correct. The fuel filter bracket washer is definitely a flat/plain washer.
This is a mistake in description in the 63 AIM and has caused problems for years. Most/all of the reproduction folks firmly believe it's supposed to be a lock washer because of the "noun description" in the AIM.
Because parts were not ordered by description at the St Louis assembly plant, for very obvious reasons, the correct flat washer arrived when the part number 120394 was ordered.

Imagine St Louis ordering parts by description; "Hey Wilbur, send us about 2000 of those little black bracket gizmos that hold the thing on the manifold".

The error in the AIM carried over to the reproduction industry and eventually, the 63-64 Judging Guide. A correction request was submitted and hopefully, it will show up in the new 6th edition.

[Doug L.]

Re: 63/64 HP fuel filter assembly

AIM. That's what I intended to say.

So is there another page showing the fuel filter hardware? I'm still trying to figure out if there is any logic to the order in the AIM.

Doug

[Timothy B.]

Re: 63/64 HP fuel filter assembly

Post #18 in the attached thread shows the flat washer on a original exhaust stud. This is the same arrangement as the fuel filter with flat washer and thin bolt.

https://www.forums.ncrs.org/showthread.php?t=65126

[Alan D.]

Re: 63/64 HP fuel filter assembly

Doug, Sec L75 sheet1.00 shows "view A" which lists the hardware. Leave second inquiry to the pros

[John H.]

Re: 63/64 HP fuel filter assembly

I'm still trying to figure out if there is any logic to the order in the AIM.

Doug

Doug -

Actually, there's logical rhyme and reason to the way the A.I.M. is organized, so it matches the Engineering Release System - this article explains it:

http://www.camaros.org/AIM.shtml

[Alan D.]

Re: 63/64 HP fuel filter assembly

Timothy,
"This is the same arrangement as the fuel filter with flat washer and thin bolt."
And the AIM calls it a "L Washer" - just to add to the confusion a little more
However think we agree its just a plain old washer. (& thin nut)

[John D.]

Re: 63/64 HP fuel filter assembly

Excellent post Alan. For an eon now most of the car 63 to 65 FI owners,etc have been using a star washer under the thin hex nut holding the fuel filter bracket on.
When in fact it's exactly like you and others said here.

I personally would be over joyed to see the car owners pitch the fake outside star washer and use the SAE flat washer. Hanson would be also as he has been preaching this for decades. So has Jorjorian.

As mentioned above the Aims does in fact call it a L washer. But the part number is for a flat washer. Look that part number up in the Standard Parts book.
Group 8.929 (washers, flat) 120394 ID: 13/32, OD 13/16, Thickness: 5/64, Finish Steel. Unit package 500

My 63, the LWC has had the flat washer on the fuel filter bracket stud since 2006.
Alan, Why don't you write an article and send it in to Vinnie for possible publication on this subject. There just has to be many thousands of Corvettes out there with the incorrect washer on them. Thanks very much, John