The Stovebolt Site Forums The Shop Area Engine Shop 58 261 oil filter leak

hello everyone, i just picked up a 1958 chevrolet viking 60. it has its factory 261 all stock and i got it running as it is. pretty cool no noises, no issues, gauge showed good oil pressure. so after i knew it ran i changed the oil and the filter. replaced the old seal in the canister lid and now it pours out from between the lid and the canister. i cant even run the truck anymore cause it will puke out all its oil in a minute. i am using 15-40 for oil im just not sure what to do.

also can anyone tell me which way the oil flows through the canister? does it come in through the bottom and out through the side port?

thanks!

Wrong gasket. Hope you saved the old one to take with you to match up.

I ran into the same gasket issue with my ‘59 235. There are several different canister sizes that use the same filter element. If you didn’t save the gasket, measure the top of the filter housing and take the filter top with you to match it up.

i had the old gasket and it matches up perfectly with the new one. i was wondering if theres a clogged line which is why i was interested in which line was the return to the block.

gaskets are identical. i matched them up for size and thickness too. ill have to try and look into it a little harder to find what else it could be.

The AC filter housings are usually marked "inlet" on the side fitting. Here's a NOS unit in my shop, AC S-6, a bit older vintage than '58, but that shouldn't matter. Makes sense, since the oil should flow from outside the filter element to inside. You may want to check to make sure the small hole in the side of the center pipe in the housing is clear.

Thank you very much! mine is so rusty you cant see the letters i honestly didnt think they were even there. now i know there to start by cleaning the lines out and checking for blockages.

does anyone know what the oil filter part # is? just out of curiosity i wanted to know what "Big A 92500" crossed over to from wix or ac delco etc. thats the only numbers on the old canister filter.

There's a very good tech tip on filters on this site. I believe your problem is simply "not tight enough" on the center cap bolt. There's a lot of upward thrust on the cover from oil pressure (like hundreds of pounds) trying to lift the cover off the gasket, so you really have to sock the bolt down tight. At 30 PSI of oil pressure, each square inch of the cover receives a lifting force of 30 pounds. If there's 12 square inches of surface area involved that's 12 X 30- - - - -360 pounds of push on the cover trying to lift it off the gasket!

https://www.stovebolt.com/techtips/engines/oil%20filters/index.html

Jerry

Just asking here but I knida remember reading/hearing, and was under the impression that, the 261 oil filters, the large full flow truck filters, were problematic. That they in fact had a pressure blow out issue with seals, lines, and were prone to spraying oil over the exhaust manifold and causing a fire. Am I remembering/recalling this incorrectly?

i didnt know how much torque the cover bolt could take, when i initially took it off to do the oil change it wasnt hard at all (also didnt leak before that) the service manual says 5-8 ft/lbs of torque on the cover bolt. now i cranked it down pretty good but i was worried about stripping the threads so i didnt go crazy and i dont have a replacement for it. im thinking about swapping it over to a spin on filter with a remote adapter. would have been nice to just leave it alone though

that would be useful information if its true!! if thats the case then i will definitely be swapping over to a screw on style filter adapter.

I'm with HRL, remove the lid and check that the gasket is not damaged and seated correctly. Replace the lid onto the canister carefully and it make sure it is seated properly. The fastening bolt has to be really torqued down until it feels like the lid is being distorted (it's not). Otherwise it will pump lots of oil out around the sides as you describe,- been there done that!

Using a spin-on filter is a huge leap backwards in filtering ability, and unless you also install a 1/16" diameter restrictor in the return line you're going to destroy the engine with low oil pressure. How big are the lines from the engine to the filter and back to the engine? If they're small flexible lines, like less than 1/2" outside diameter, you've got a "bypass" filter that only runs part of the oil to the filter and dumps it back into the oil pan. The rest of the oil goes to lubricate the engine. Some late model 261's used a "full flow" filter with huge oil lines to and from the filter and flowed all the lubricating oil to the filter before supplying the engine with oil. That system used a tall, large-diameter canister with flexible lines with 1/2" pipe thread fittings, and a different routing of the oil inside the engine block.

DO NOT mess with the filter system until you fully understand how to make modifications properly. Right now, you've got a pretty simple leak problem. Don't destroy your engine in the process of trying to solve an annoying leak by making inappropriate modifications to a system that's worked well for over 70 years on millions of vehicles.
Jerry

ill give that a shot today then, double checking the filter gasket, if its messed up ill just buy another filter so i can get a new gasket and swap them both in. but youve described the problem to a t the oil just pours out all around the canister its not just 1 spot. ill check it then crank it down hard


the line going to the filter is probably 1/2 inch. the line going back to the block was smaller for sure. probably 3/8"

Some filter elements come with two gaskets in the package, one wider than the other. Use whichever one fits your particular canister lid the best. I believe that Fram and AC canisters were able to use the same filter cartridge, but they required a different cover gasket. The diameter of the cartridge might not completely fill the canister, but the rubber grommets are supposed to be a snug fit on the center standpipe. If you clean the canister well and shine a bright light on the standpipe, you should be able to see a tiny hole (1/16") in the pipe a few inches below the top. That is the flow control restrictor that prevents the filter from starving the engine for oil as it bypasses some of the oil directly back to the pan. (Assuming you have the filter with the small supply and return lines).
Jerry

there is a very small hole just below where the bolt would bottom out the o rings for the filter are snug against the standpipe. its clean and clear. the filter cartridge came with 2 gaskets i used the wider gasket as thats the one that matched the old gasket. the more you describe it the more it seems like the bypass type system where it doesnt have massive lines they are pretty small fittings that go into the canister and the block, i appreciate all the info and all the help!

Later model 261's had the option of running a full flow filter, but I don't think that was available in 1958. Those engines will have two large pipe plugs (1/2" NPT) on the driver's side near the exhaust pipe, and a round dowel pin that must be driven into the block about 1/2" to change the oil flow from the pump to the bearings. When that is done, all the oil from the pump passes through large-diameter flex lines after it leaves the pump, goes through a tall, large filter canister, and then re-enters the engine to provide lubrication. That's the system Dragsix was referring to when he mentioned leaks. A bypass filter line can also spring a disastrous leak and pump the engine dry or start a fire, so be sure the flex lines are in good condition. Some people choose to plumb the filter with hard line tubing and add a "vibration loop" to the plumbing to prevent the lines from stress-cracking. That's OK as long as the filter housing is on the engine somewhere like the intake manifold, not mounted over on a fender well, etc.

Since oil filters were often dealer-instaslled options, using flex lines to connect them made more sense than hving hard lines made up to fit a lot of different filter mounting locations.
Jerry

Supposedly,1958 was the first year for the 261 optional full-flow oil filter.

http://www.oldchevytrucks.com/articles/261-engine.php

Thanks, Tim! For some reason, I thought the full flow setup was incorporated in 59. I've got a 59 engine stashed away with that option, but it's currently set up for bypass filtering. When I put it into service, I'll probably use both types of filters, with the bypass being a "Frantz" style toilet paper cartridge in a stock-appearing AC housing. It's fairly simple to do that conversion.
Jerry

http://devestechnet.com/Home/TheVenerable261

found that link very bottom of the page shows me what im looking for as far as it being full flow or bypass style but incase anyone else would like to learn a little i posted the link here.



EDIT: i didnt know anything about the history between this forum and the link i found. i found it on this forum while searching for 261 threads. so if it is a problem to anyone i can remove it. or if its false info id like to know about it and remove it as well. i dont want to steer anyone wrong especially while learning myself.