PF-131 Oil Filter Canister Restoration

[Greg K.]

Does anyone know where to buy the copper washer (.500" ID x .812" OD x .032" thick), o-ring (.484" ID x .139" cross section/thick) and snap ring (Waldes #5100-50) for reassembly and retention of the bolt? I have a canister I'm wanting to restore (it leaks) but don't want to start this project until I can find these parts. Any help would be greatly appreciated.

[James W.]

Read this article. It works, parts list is at the end. The person who wrote this is an NCRS member.

James

https://www.corvetteforum.com/forums...KIe6yszSPbSPVw

[Kurt K.]

Clips and Fasteners, 7/16 Copper Washer 1/2"I.D. 7/8"O.D. 1/16" Thick. Part # FBA15918-25. Amazon sells them. 25 in pack.
I elected not to use the snap ring. The filter holds everything in place when it's on the car.

[Greg K.]

James, I saw that article a while ago. I was looking at John Bradley's article and parts list. Looking at Corvette Forum article I could find his parts.

Kurt, Using that part number I could not find any copper washers. I did find Dorman 725-005BX Copper Washer-1/16" x 1/2" x 7/8" for $14.+ on Walmart & McMaster-Carr websites (20 pak & 10 pak respevtivey).

Thanks guys.

[Gary B.]

Kurt,

Do you know for a fact that your Amazon choice of a copper washer is reasonable for the sealing requirement for the oil canister? There are at least six ASTM grades of copper, ranging from soft to hard. For sealing, a relatively soft grade is appropriate, like would be used for crush washers. A hard copper washer would not be a good choice.

Gary

[James W.]

Greg,

I believe the parts needed from McMaster-Carr are listed below.

James


"The copper washer between the head of the bolt and the bottom of the canister… When discussing this part with my consultant I told him I could probably get this part at my local NAPA store. He said, “No, they’re too thin. They need to be about 1/16th thick. So, I purchased from McMasterCarr the following items:

• 110 Copper Ring Shim 0.064" Thick, 1/2" ID, part # 94397A643
• Oil-Resistant Buna-N O-Ring 1/8 Fractional Width, part # 9452K185
• 18-8 Stainless Steel Washer for 15/32" Screw Size, 0.500" ID, 1" OD, part # 92141A232
• External Retaining Ring for 1/2" OD, 15-7 PH Stainless Steel, part # 91590A122

Please be aware that the copper washer needs to be a soft copper. That’s one of the reasons I purchased the copper washers from McMasterCarr - because the properties of their parts are on full display. This 110 copper washer is soft and is thick (1/16th) like in the original GM assemblies and is a perfect match for this assembly.

The o-ring listed above is oil-resistant. If you find a better o-ring please share it below.

The stainless steel washer(s)... I used 2 of them and I’ll explain why here… The steel washer in the assembly (on top of the spring and below the o-ring) from the seller/restorer was very thin (too thin for my comfort) and could possibly be deformed under pressure. This washer sits on top of the spring which is not a flat surface where the end of the coil meets the other coil and is the base for the o-ring that sits under the cup. Thinking that the base for the o-ring should probably be a firm, inflexible surface I chose a thicker steel shim or steel washer for the job and replaced the much thinner steel washer in the prior assembly. This is where I used one of the SS washers. The location where I used the other SS washer was between the cup and the external snap ring retainer. Remember (from above) when we removed the jagged edges and irregularities of the top lip of the cup, and remember in doing so this enlarged the opening of the top lip of the cup where it interfaces with the retainer? Well, because the opening of the top of the cup is a little bigger than it was originally I didn’t want the possibility of the cup slipping up/past/around the external snap ring retainer so I installed the second steel washer between the top of the cup and the bottom of the external snap ring retainer."

[Gary B.]

…
"The copper washer between the head of the bolt and the bottom of the canister… When discussing this part with my consultant I told him I could probably get this part at my local NAPA store. He said, “No, they’re too thin. They need to be about 1/16th thick. So, I purchased from McMasterCarr the following items:

• 110 Copper Ring Shim 0.064" Thick, 1/2" ID, part # 94397A643
• Oil-Resistant Buna-N O-Ring 1/8 Fractional Width, part # 9452K185
• 18-8 Stainless Steel Washer for 15/32" Screw Size, 0.500" ID, 1" OD, part # 92141A232
• External Retaining Ring for 1/2" OD, 15-7 PH Stainless Steel, part # 91590A122

Please be aware that the copper washer needs to be a soft copper. That’s one of the reasons I purchased the copper washers from McMasterCarr - because the properties of their parts are on full display. This 110 copper washer is soft and is thick (1/16th) like in the original GM assemblies and is a perfect match for this assembly.

…

James,

Earlier today I posted a question to CADbrian (on the Corvette Forum), who I believe is the author of the above description of the canister rebuild, and the required parts, including the all-important copper washer. My question to CADbrian is why did he chose the 110 Copper (yes, I know he says because it’s “soft”) rather than a copper crush washer which McMaster-Carr specifically describes as for a sealing application, where the washer needs to be malleable (soft) enough to deform in order to seal. I am not a materials scientist, so I don’t know the difference between 110 copper and whatever grade of copper is used for crush washers. I presume one is softer than the other. But which is which? I tend to trust manufacturers more than hobbyists when it comes to recommending what is best or better for certain applications. Now maybe CADbrian is knowledgeable enough to make the choice between 110 copper and a copper crush washer, but I would like to hear his response.

Gary

[James W.]

James,

Earlier today I posted a question to CADbrian (on the Corvette Forum), who I believe is the author of the above description of the canister rebuild, and the required parts, including the all-important copper washer. My question to CADbrian is why did he chose the 110 Copper (yes, I know he says because it’s “soft”) rather than a copper crush washer which McMaster-Carr specifically describes as for a sealing application, where the washer needs to be malleable (soft) enough to deform in order to seal. I am not a materials scientist, so I don’t know the difference between 110 copper and whatever grade of copper is used for crush washers. I presume one is softer than the other. But which is which? I tend to trust manufacturers more than hobbyists when it comes to recommending what is best or better for certain applications. Now maybe CADbrian is knowledgeable enough to make the choice between 110 copper and a copper crush washer, but I would like to hear his response.

Gary

Gary,

I know Brian. I will get an answer from him and let you know. Let's just say that his "consultant" may be someone that is well know in the Corvette "hobby", and had been rebuilding these for years. This is just my hunch.

James

[Gary B.]

James,

Thanks for checking with Brian.

There are several places on C2s where copper washers are used in situations where the sealing of fluids is required. Another place is the 63-64 wheel cylinder to brake hose and the 65-82 front caliber to brake hose. Commenting on those brake copper washers In a 2022 posting Joe Lucia said:

”The wheel cylinder-to-brake hose seals at the copper washer. The same is true for caliper-to-brake hose for 1965-82 front calipers.

Hydraulic brake systems operate, of course, at very high pressure when the brakes are applied. So, the sealing is challenged. The sealing surfaces of the wheel cylinder/caliper and brake hose fitting flange are critical and need to be perfect. You will note the "concentric rings" seen on the wheel cylinder/caliper sealing surface. This is an important part of the sealing function.

The other critical part of the sealing system is, of course, the copper washer. Sometimes this is taken for granted. However, this washer needs to be dead soft copper and not some harder copper alloy. I think that some of the copper washers "out there" are too hard and will not seal well.“

Joe mentions “copper alloy”, but the issue is not just (pure) copper vs copper alloy. Copper which is not alloyed is available in a range of hardness. Not every copper washer sold on Amazon or McMaster-Carr or wherever, of the same dimensions as the GM original washers, will work like the original GM washer did. It’s not a big deal with the oil canister, as a too hard copper washer might just lead to an annoying oil drip. The brake hose to caliper seal is obviously much more important

Gary

[Gary B.]

This table shows why just choosing 110 copper doesn’t tell you everything you need to know about its malleability.

[Gary B.]

James,

I hadn’t read it before, but the description on the McMaster-Carr webpage for the copper shims that Brian spec’ed make it sound like they should be soft enough. It describes them as “our softest metal shims”. Other than dimensional tolerances, I don’t know how those copper shims compare to what McMaster-Carr sells in their copper crush washer category.

Gary

[Gary B.]

A customer support person at McMaster-Carr told me this about the copper crush washer and copper shim washer):

“The washer (97725A232) is grade 110 and half hard. The shim (94397A643) is also grade 110 and half hard.“

Gary

[Kurt K.]

I just annealed my washers. If you can bend it with just your fingers it should be soft enough to seal properly.

[Gary B.]

Kurt,

That will do it!

Gary