Chris,
You didn’t say which line burst. I recommend you test your oil pressure sender. Hook it up to your air compressor hose and compare the two readings. You should be able to do this close to the engine so you can read it.
Check the hose and fittings after the filter (all of them) for some kind of blockage. If the sender is ok, you may have a blockage between the filter and the sender. Could be the exit from the filter adapter.
Did you make up your own hoses and install the ends? If you didn’t use a mandrel, it is possible to get a sliver of the inside of the hose that could come up and partially block the hose.
Like Al, I don’t see how this could happen. Maybe Lynn will know.
Bill B
The Teflon lined braided stainless hose uses the braid as the pressure bearing media. The liner is Teflon and has no strength at all. Just a fluid conduit. Typical ratings are 1500 pounds working and 3000 pounds burst. If I remember correctly (who am I kidding?) that 3000 pounds would be for one hour at max rated pressure and temperature without failure.
On used hose you will see the outside of the liner has extruded into the braid when run close to burst. The advantages are light weight, available at the local hot rod shop, relative low cost, and they are pretty.
There are many brands to choose from. Goodrich, Goodyear and Aeroquip are the best known. There are also house brands (like the name of the chain store where the hose is sold). New old stock from military sales is an excelent source. Although the shelf life may be expired, the half life of Teflon is probably 5,000 years, so it will last long enough for us. The real military stuff has a metal tag on every hose. That tag has the NSN (National Stock Number) A long P/N the government applies to every part. The contract number (minimum) the working pressure, and may have the Cage Code (identifies the manufacturer) the manufacturers part number, the burst pressure.
The fittings from different manufacturers should not be interchanged. The fittings from different styles from the same manufacturer should not be interchanged. Be aware that AN (Airforce-Navy Standard) (the airplane stuff) and JIC (Joint Industry Standard) look identical. The SAE hose looks exactly the same as well but will more likely have 45 drgree flair angles rather than 37 degree flair angles.
This is one of many sites that explain hose use well...............
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Introduction
If you want to separate yourself and your car from the amateurs you have to stop using cheap rubber hose and clamps to plumb the vital fluids to your motor. That stuff works and gets you by, but it is not classy and has major limitations in durability and more importantly, safety. Most racing bodies, like the NHRA, do not allow more than a six inch stretch of rubber hose for things like fuel and oil lines. They mandate that those fluids flow through hard-line or steel braided line as those two materials are unlikely to burst, melt, or be cut in the event of a mishap. That is why the top race cars at the track have motors decked out in steel braided line and those spiffy red and blue fittings - it is due to safety and durability, not just because it looks cool. The greatest benefit to AN (pronounce each letter) is in the sealing capability. A connection between male and female AN flares can handle tremendous pressure without leaking, making it the right choice for oil, fuel or water. In this article we'll give you the entire scoop on how to properly plumb your car with AN hard and soft line.
Background
AN stands for "Air Force-Navy Aeronautical Standard" and was an aviation fitting standard developed around WWII. The fitting featured a 37 degree mating angle which provided superior sealing compared to the common 45 degree fittings. The fittings also utilized a higher class of
| 3 key facts about AN fittings. |
 Flare angle is 37°, not 45° |
| Interchangeable with JIC fittings |
| Divide AN # by 16 to get inches | |
thread quality. Eventually the AN fittings saw widespread military use and a multiple manufacturers began producing the fittings, leading to quality problems. The Joint Industries Council (JIC), an industry organization, sought to standardize the specifications on this type of fitting and created the "JIC" fitting standard, a 37 degree fitting with a slightly lower class of thread quality than the military AN version. The SAE went on to adopt the JIC standard as well. As a result JIC or SAE 37 degree fittings are perfectly interchangeable with AN fittings, and while this may not be acceptable for military aviation use, for automotive use there is no downside other than perhaps mismatched color coordination as JIC fittings are not available in the pretty anodize aluminum colors. However this may be a worthy tradeoff considering the JIC fittings are a fraction of the price of their true "AN" counterparts. We mixed and matched in this article to show you their interchangeability.
Using AN
A half-dozen companies make AN fittings, hose, and line and most all of it is interchangeable except for certain proprietary "push on" type hoses and fittings. Always check the manufacturers information before purchasing hose or hose ends to make sure it is compatible. The AN side will always be 37°, it is the hose side that can vary depending on manufacturer designs. AN components come in easy to understand sizes, all divisible by 16 for easy conversion into fractions of one inch. For example, a -8AN (dash 8 AN) hose is 8/16" inner diameter, or 1/2" inch. AN is generally available in -4 to -12, and larger specialty sizes.
When selecting AN you must determine if you need to use hard line or soft line (generally Teflon, rubber, or special material with a steel braided or other protective sheath) or a combination of both. Hard line is not specific to AN, and this can be aluminum or steel and can be sourced from any hardware supply store. In other words 1/2" aluminum tubing is compatible with -8AN fittings. Soft line is AN specific because it needs to mate properly with the hose ends (as we'll show you later in this article.) When selecting soft line be sure to use hose material that is compatible with the fluid and pressure you plan to run through it.
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So, what to do. If there is any doubt about the use or applications or assembly, take the hose to your local hose shop and have them checked by a professional. They will gleefully explode any sub-par and Chinese replica hoses in their test cell, usually for free. They will also test any hose they make up for you before you pay for it.
The big three make lines of hose and fittings for hot rod use. They are easy to assemble, and when done properly can withstand the factory tests for pullout and burst.
How did the hose fail?
If it was a name brand assembled by the manufacturer it would fail above 3000 pounds. A figure not available from a powdered metal oil pump in the Mazda engine. So let us suggest that failure happened well below the burst rating of the hose. The later Mazda front covers have improved the "O" ring junction that would blow out and loose oil pressure on older 13Bs. The front cover is still way too flexible and that junction would still leak because the cover will be pushed off of the junction by an over pressure. Early 13Bs had a reliefe valve in the cover (looks like a brass bolt head) that opens at 144 pounds to protect the "O" ring junction and the stock oil cooler from damage in a cold start. The relief valve at the bottom of the rear iron in early engines was a piece that could be disassembled and adjusted to produce any oil pressure you might want to run. In stock form it produced 71 pounds of pressure. In turbo engines and Renesis the valve is welded shut and set at 110 to 115 pounds.
So,
If the front relief and "O" ring junction is not used, and the whole oil supply is delivered to the oil filter stand, there must be a restriction in the hose beyond the failure point, or in the filter stand.
Remote filter stands flow outside-in. If you look at the top of the filter, the little holes around the outside is where the oil goes into the filter. Oil exits through the center hole. If the filter can has the anti drainback feature, you will see some black rubber through the little holes areound the outside.
When these cans are installed upside down that black rubber flap keeps oil from running back out of the filter for a month or so. So, in most cases you can get oil pressure in short order on start-up, rather than having to run the engine for 15 or 30 seconds before you see oil pressure.
With the number of cans that have been tried on this installation and this is the second filter stand.
My bet is on a defective hose from the git-go that hase been the source of the leak all along.
That would fit best in my mind. There is no excessive oil pressure. The hose never saw its burst rating. It was failed before it was installed.
Lynn E. Hanover
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