I need to replace my 1/4" rear brake supply line with new 1/4" line I ordered (FMSI #P4) and the rear tube nut from the original line will not fit over the new 1/4" line. I'm guessing that this is because the original 1/4" line is actually 6mm, and the replacement line is a true 1/4", which would mean it's actually 6.35mm. The slightly larger diameter must hamper the nut enough so that it won't slip over the line. Regardless, I need a new tube nut. However, none of the parts stores I go to have any 1/4" bubble flare nuts (I think it's bubble flare... looks like it?), nor can they order them (plenty of 3/16" bubble flare though). FMSI doesn't even seem to carry them, so I'm not sure it's a bubble flare tube nut, or they just don't make them anymore.

I have the Earl's hyperfirm kit, which gave me a new stainless steel braided differential flex hose. Can I upgrade the tube nut to a 1/4" inverted flare, and then use that to connect to the hyperfirm hose (came in the kit for 4-wheel discs)? If so, that'd be great, and solve the problem of finding 1/4" bubbleflare fittings.

Thanks for the help.

 

if the nut wont fit then swap it from the original line- its not hard at all, just cut off the line end and swap the nut and double flare the end

real easy

i dont know why ppl think they have ot have fancy lines and stuff, i dont understand it

nothing is wrong with the lengths of hardlines at auto zone and so forth, i have used the stuff on a million different vehicles all with never a single problem ever, for years upon years

getting ready to replace the old crusty rusted and blown rear line on a 97 C-1500 pickup most lijely tomorrow

will be yet again using the trusty old auto zone tubing and the trusty ol 15 dollar tubing double flaring kit


if you cannot simply swap the nut from the old to the new then please elabortae why not

pics?


good luck

 

My post said that's what I did, and it doesn't fit.

Fancy nothing, FMSI is far from a fancy company. They have OEM-equivalent stuff at a decent price ($15 per 25'). I did not want to shell out the money for custom bent replacement lines from Fine Lines, Inline Tube, or Classic Tube, when I'm going to modify the line for a proportioning valve. My original 6mm (or 1/4") line was bad and wouldn't flare with my tools (hydraulic Mastercool flaring tool). The nut from the original line would not fit the new 1/4" line I purchased to replace it.

Perhaps you are getting confused. I am talking about the 1/4" rear supply line, not the 3/16" line that goes to every caliper. Yes, those can be bought or ordered at any auto parts store, but not 1/4" line (at least from the shops I checked).

I have nothing against those trusty 'ol parts/tools, as I have some myself. However, I need a tube nut that's compatible with a bubble flare end: ----(), not a double flare (also known as a 45 degree double flare, or inverted flare) which has the end bent back on itself (an inverted cone): ----<<

Here you go. The nut won't slip over, not even with some persuasion. Normal 1/4" inverted flare nuts purchased at Napa slip over fine, so this nut must be 6mm or something slightly smaller that doesn't want to fit. Besides, the threads are less than satisfactory, so I should use a new nut anyways.

 

Found it! Classic Tube said the tube nut is 1/4" 12mm x 1.0 bubble flare.

 

Hey Kev,
I don't know if your resolved your nut issue yet, but why not just drill out the nut so the nut will slip over the tube. I think that would be a quick and easy fix.

 

Good idea Oscar, but I had to get a new one anyways as the old one had some messed up threads. And yes, I figured out the nut, now I'm just waiting for it to get here.

 

Randy, the brake line that he is talking about is not the same diameter as all the lines sold in the store, it is a true 6mm line. Like stated above, the 1/4 is slightly larger and therefore the nut willnot fit. (on a caliper I measured the 2 lines and it was VERY close) I was having the same problem as him. The solution i did is one that was stated above. I drilled the old peice with a 1/4 inch bit for my new lines. You have to be careful to do it straight. Glad to see everything worked out.