# Brake tubing question



## 89D21 (Jan 22, 2008)

I've got some crazy rust in the rear of my truck... some of which has affected some of the tubing for the brakes. Anyone know the sizing of the OEM brake tubing and fittings so I can replace some of the crusty lines? Looks to me like 3/16" but I just need to verify that and the size of the fittings.


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## 89D21 (Jan 22, 2008)

Anyone know off the top of their heads the size of those lines? I'm hoping to replace pads, rotors, shoes, e-brake cables, master cyl., lines and bleed the whole thing out this weekend...


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## nismo_d21 (Jan 26, 2008)

When I replaced mine, I went to my auto parts store to see if they had my wheel cylinder in stock. I got luck and they did, so I had them match up the tubing to the wheel cylinder size. What I would recommend is to get two just in case because the tubing is thin, take your time while bending it and try to use a round surface to bend it against instead of just using your hands so it doesn't get pinched. I would give you the size I used but I honestly can't remember what it was, I think it should be somewhere around 3/16 but don't hold me to it.


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## nismo_d21 (Jan 26, 2008)

Correction, It should be 7/16. I just got back home and measured the spare tube I have in the garage. Good luck.


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## 89D21 (Jan 22, 2008)

nismo_d21 said:


> Correction, It should be 7/16. I just got back home and measured the spare tube I have in the garage. Good luck.


Awesome - thanks for the help Nismo. Heading out to the parts store after work today to pick up those lines.


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## smj999smj (Jan 1, 2006)

7/16" would be the size of the wrench you use on the line fitting, not the tubing size. Technically, the tubing is 4.5MM, which is essentially 3/16" and the size you will find at the parts store. FYI, metal fuel line is typically 5/16" or, in some applications (high performance use, for example), 3/8".


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## nismo_d21 (Jan 26, 2008)

7/16 is the size of the fitting that is on each end of the tubing. The size of the wrench needed is actually a 12mm believe it or not.


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## smj999smj (Jan 1, 2006)

On the vehicle, the fitting should be 10MM.


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## nismo_d21 (Jan 26, 2008)

Ok, on my truck, fitting that goes into the wheel cylinder is 7/16 and the wrench for it is 12mm.


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## 89D21 (Jan 22, 2008)

The parts store didn't have any in stock so I went home and double checked. 7/16 looked huge for brake line so I figured that might've been a typo or something. Anyway, 3/16 is what I figured for the tubing but the fitting is 10mm as in M10x1.0,1.25,1.5?? I've got some fittings left over from when I replumbed the brakes in my CR-X so I'll try those - or if anyone knows the actual metric size.. (not wrench size). If I can't figure it out soon I'll probably end up buying one of those "brake kits" that has an assortment of fittings - kind of learning by trial and error.


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