canister type oil filter washer?

[1955CJ-5]

This has happened before....

Changed the oil and canister filter element. 

Tightened everything, I let the engine run and I watched the oil filter for leaks....everything is fine, not a stray drop.

I went for a short 2 mile drive and when I got home there was oil everywhere!

It came from around the center bolt in the oil canister cap...

So, I have a copper washer in there. It's not a crush washer.

Does anyone know what type and size washer( I did measure it but promptly forgot the size..but it was less than 1/2")  is supposed to be in there, or what works for you?

For now I've tightened it as tight as I dare and it's not leaking, but I'd like to get the correct washer in there to prevent future problems.

Mcmaster-Carr has all sorts of crush washers, copper and aluminum....so plenty available.

Thanks!

Randy

[Rus Curtis]

Randy,
Your signature block indicates a CJ-3A.  Is that what we're looking at in the image?

I just took my bolt out to measure (CJ-3B - could very well be a different canister).  I got 7/16" on the bolt size but it has a "shoulder" under the head so that there's a larger surface to seal against the washer - like this "Flanged Hex Head bolt: https://www.mcmaster.com/hex-bolts/head-type~hex/medium-strength-grade-5-steel-flanged-hex-head-screws/ 

My washer has been stuck on the cover for some time and I didn't want to disturb it but it appears to be fiber (not copper).  The outside diameter of that washer was 3/4" but it matches the flanged shoulder under the head of the bolt.

I looked at Walck's (didn't have anything) and KW (had a hardware style bolt but no gasket).  rfjp had a copper washer available.

Using the bolt you have I'd think the washer you get (copper may be good) shouldn't extend too fare outside the head.

HTH

[1955CJ-5]

Hi Rus,

Thanks for the reply.

Yes it's for the CJ-3a, the CJ-5 uses the same filter element but the bolt is different.

Looks like a 3/4 head on the CJ-5 and the 3A takes a 7/8" wrench.

I also had looked at Walck's and KW, didn't think of Ron Fitzpatrick....sometimes those military filters are larger, but I did find the washer you mentioned..

https://www.vintagejeeps.com/p-131-oil-filter-cover-bolt-gasket-a1233.aspx

I may have to just take it apart again.....would like to have a replacement handy when I do though!

I think my 3a  bolt has a flat mating surface but no flange....it does have a raised letter "T" on it and a number.."1035"

Attached is a picture of the CJ-5 filter bolt, sounds like the one you described.

Randy.

[1955CJ-5]

Turns out I have a box of the A-1233 gasket/washers as offered by Ron Fitzpatrick.

https://www.vintagejeeps.com/p-131-oil-filter-cover-bolt-gasket-a1233.aspx

Unfortunately they are too large....

[squidtone]

I also wondered what was the "original" material used for the washer. When I got my engine, there was no washer at all (the filter housing was in a box of parts). I ended up making a washer out of heavy duty exhaust gasket material. I don't know what kind it is as I've had it for years and years. But it seals well but I still have to really snug down that bolt.

If you want to keep using an old copper washer, it may be work hardened. I believe you can "anneal" the copper by heating it with a propane torch. (this is unlike how to anneal steel alloys). THe copper will be soft again and perhaps it will seal better...

[1955CJ-5]

Tomorrow I will take the cap bolt off and go find a replacement washer/gasket.

This time I'll measure it and....write it down!

If I can't find a replacement then annealing the old one is a great idea.......I'm pretty sure the washer I'm using had to be filed out to fit...tedious but it worked...mostly.

[1955CJ-5]

I took it apart again and measured. The bolt is .436" so 7/16, as Rus had posted, ought to work.

I annealed the old washer and put it back together and ordered crush washers from Summit racing.

[1955CJ-5]

So somewhere between 1951 and 1955 they revised/improved the oil cannister. Maybe I'm not the only one who has has issues with it!

Attached are pics of the 3a canister top and bolt, and the CJ-5 cannister top and bolt. The CJ-5 top has what looks like a machined surface for the fiber sealing gasket. Looks just like what Rus described in reply #1.