The only time a lowrider should sport a standard black rubber coolant hose is if you’re going for a full factory spec resto. Other than that, we don’t want to see one amidst a sea of chrome. It’s just not right.

That said, an aftermarket coolant hose is one of the first things you should add. It’s a simple detail that goes a long away so that’s what we’ll be talking about in this issue. For our LS, we decided to visit Summit Racing to see what they had and we then decided that making our own would be the best bet. To do that, we ordered a couple of 16-gauge, 1 1/2-inch-diameter mild-steel, mandrel-bent U-bend pieces. In addition, we picked up a 7 1/2-foot, 16-gauge, 1 1/2-inch-diameter piece of straight tube.

Once they arrived we got to work, and thanks to a bit of past welding experience—and a whole lot of patience and measuring—we made moves and finished off our custom coolant pipe in just about three hours.

Of course, buying an aftermarket stainless steel coolant pipe would be much easier and cost effective but you can’t beat the look of a well-crafted mandrel bent unit like the one we just built.

how to make custom coolant lines using exhaust tubing summit racing 16 gauge exhaust tubing

1. After browsing online, we wound up ordering two 16-gauge, 1 1/2-inch mild-steel U-bends (PN SCH-015016U) and one straight length (PN WLK-47980) of the same gauge and diameter exhaust piping from Summit Racing. All three pieces only set us back about $40.

how to make custom coolant lines using exhaust tubing exhust tube u bend marking

2. Using a Sharpie, we marked the dead center of our first U-bend in order to create our first 90-degree turn.

how to make custom coolant lines using exhaust tubing band saw cutting

3. To cut the U-bend you can use a hacksaw or a cutoff wheel but the best results come from using a bandsaw.

how to make custom coolant lines using exhaust tubing burr cleaning

4. Clean whatever burrs may be left after the cut. You can use a wire wheel, deburring tool, or whatever’s handy.

how to make custom coolant lines using exhaust tubing coolant line mock

5. Using hose clamps and a bit of 1 1/2-inch id hose, we then mocked in the first cut coming off of the water pump’s outlet to get an idea of where to cut the second piece going into our AutoRad radiator.

how to make custom coolant lines using exhaust tubing second coolant line piece

6. Using the other half of the U-bend tubing we cut earlier, a mark was made indicating where to cut the second piece of our hardline.

how to make custom coolant lines using exhaust tubing eastwood bandsaw

7. Using Eastwood’s Benchtop bandsaw made cutting the tubing quick and easy.

how to make custom coolant lines using exhaust tubing coolant tubing mock up

8. We mocked in both pieces of tubing and then marked a straight line from one to the other to ensure the correct orientation once we started welding.

how to make custom coolant lines using exhaust tubing exhaust tubing tig welding

9. Using our Miller Diversion 180 welder loaded with 1/16-inch tungsten, we used 1/16-inch rod and welded the ends together, making sure to get a good bead all the way around the tubing.

how to make custom coolant lines using exhaust tubing coolant tube welds

10. You can see the nice thick bead all the way around the tube. We weren’t concerned about aesthetics at this point.

how to make custom coolant lines using exhaust tubing weld grinding

11. We then smoothed the welds down by using an angle grinder topped with a 36-grit Rolox disc.

how to make custom coolant lines using exhaust tubing weld sanding

12. From there, we hit the welded area with a DA topped with 80-grit sandpaper to knock down the deeper scratches. Next, we went with 220-grit paper to get a smooth, uniform surface.

how to make custom coolant lines using exhaust tubing coolant tube sanding

13. Even though there is a little more work to do here, you can see the weld beginning to smooth out. We eventually performed the same process on the entire piece to get a uniform look.

how to make custom coolant lines using exhaust tubing coolant line radiator mock up

14. We did one last mockup before metal-finishing the entire tube.

how to make custom coolant lines using exhaust tubing lower coolant line mock up

15. For the lower hard line, we used the second U-bend and went through the same basic mockup and marking process as we did for the top hard line.

how to make custom coolant lines using exhaust tubing lower coolant tube angled cuts

16. The space is a little more confined coming from the bottom of the radiator to the thermostat housing, so we needed to make the angled cuts a little more precise than we did up top.

how to make custom coolant lines using exhaust tubing lower tube mock up marks

17. Just like up top, we mocked in the bends and marked an orienting line where the two ends need to be welded.

how to make custom coolant lines using exhaust tubing lower coolant tube welding

18. The welding process is the same for the bottom hard line as it was for the top.

how to make custom coolant lines using exhaust tubing finished lower coolant line

19. Here’s the bottom line all finished and looking sweet.

how to make custom coolant lines using exhaust tubing fabricated coolant lines

20. After about 3 hours and around $40 later, we were all done fabricating our coolant lines.