Plumbing 101: Part 7

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Last time around in our comprehensive plumbing series, we detailed exactly how to assemble and test top-of-the-line Earl’s Perform-O-Flex hose and Swivel Seal fittings. In this issue, we’ll begin the process of assembling Earl’s latest UltraPro series hose and matching fittings.

Let’s start at the top and rewind a little bit: Earl’s UltraPro series hose is constructed with an inner liner made of polytetrafluoroethylene (PTFE) – a lightweight and rugged material ideally suited for transferring fluids in high performance automotive applications, including the most extreme forms of racing. Earl’s notes: “The inner liner is carbon-infused and features a double-helix ribbed structure that supports robust flow even in applications requiring tight bends. The double helix ribbed structure also promotes superior sealing through positive engagement and retention of hose-ends. Structural integrity is enhanced even further by a glass-fiber wrap applied to the inner liner before the final application of either polyester or stainless steel braid.”

The matching UltraPro Series hose ends from Earl’s are manufactured from premium high-strength 2024-T8 aluminum and fitted with fluoroelastomer internal seals which are chemically resistant to all known fuels, oils and coolants. They feature brazed bent tubes for increased strength, and all unnecessary weight has been eliminated from UltraPro components. The result is a very lightweight hose and fitting package (the stainless braided UltraPro is up to 37% lighter than comparable stainless braided hose, and the Polyester Braided hose shown here is a whopping 67% lighter than comparable rubber lined stainless braided hose). The bottom line here is that the weight reduction alone makes it perfect for modern racecars.

One very important thing to keep in mind with the new PTFE lined hose from Earl’s is the fact it is impervious to modern gasolines. The chemical mix used in many of today’s fuels (including some pump gas blends) can attack rubber hose or braided hose with rubber liners.

Fair enough. But how does it go together? There are a couple of ways to assemble this type of hose – by hand and by machine. For our purposes here, we’re using the lightest fabric braided UltraPro hose coupled with Earl’s matching UltraPro hose ends. This type of hose can be assembled at home with common tools. Here’s how it goes together (we’ll finish up with the hose next issue):

In order to cut the hose and ready it for assembly, tightly wrap the desired cut location with Teflon (PTFE) tape. This prevents the polyester braids from fraying. Do not use any other tape (such as common duct tape) to wrap the hose.

Begin the cut with a common box cutter. Use a fresh, sharp blade. Cut the hose at the location you marked with the Teflon tape. Once the cut is approximately 90% complete, stop!

Finish the cut with a sharp pair of scissors (we use these high tech medium size serrated blade scissors available from www.cindysthreadworks.com). They’re extremely sharp and they’re specially designed to draw the fabric into the scissor jaws. This makes for a very clean cut. If necessary, the scissors can be used to trim the braid flush to the end of the hose.

DO NOT remove the Teflon tape at this point. It is important the braid should not be allowed to fray apart during assembly. It must remain in its braided state so the hose-end compression stack-up is correct.

Disassemble two fittings – one for each end of the hose. At this point, you’ll need the sockets only. Set the other pieces aside.

Once you have the hose cut to length (and the Teflon tape is still in place), slide the socket onto the hose with care. Repeat for the second socket (opposite side of the hose). Keep in mind the second socket should be put on backwards. If the socket catches on the braid or the Teflon tape, rotate the socket clockwise, threading the socket past the end of the hose. Once both of the sockets have been installed, the hose assembly should look like this:

The respective socket olives are assembled next. Gently slip the braid back away from the edge of the hose, still leaving the PTFE tape in place. The olive must be threaded onto the hose liner only.

Thread the olive past the end of the hose only enough to allow the cutting of the hose flush. If threading the olive becomes difficult by hand, you can use a pair of small channel lock pliers to thread the olive onto the liner. Use light pressure on the pliers so you don’t damage (crush) the olive.