Brake Line Compression Fittings?

[Tim Martin]

From time to time I read about using compression fittings on brake lines. I have used them already but in reading some posts on this forum there seems to be a rather negative concept regarding the use of them on brake lines. I think I understand the implications and the risks of them but I would like more input from the "experts" on this forum. Do you use them? If not, why not?

[steven kiser]

i will not use compression fittings on brake lines. i cut, flare, and use unions. i've been told it's illegal but i really don't know. i see way to many vehicles that brake or fuel lines are twisted or run in different ways to accommodate extra length, compression unions used to shorted or lengthen lines or just to splice when the line nuts have to be used from the old lines. i can't recall how many times i've seen vehicles that have enough brass on them that the scrap dealer will pay me enough for dinner. years ago i invested in a hydraulic flaring tool that will even make g.m. fuel line connectors. i use a spool of 3/16ths and 1/4 inch brake lines. have a good selection of line nuts and will even make new lines instead of using adapters on some after market wheel cylinders. i always fear restrictions in the fluid flow. i've seen compression unions over tightened to the point of 80% line collapse. my feeling is if i'm going to charge someone two or three hundred bucks to replace brake lines i don't want some other shop pointing out a series of compression unions and lines wrapped around things to make the line fit. i've seen abs blocks on g.m. trucks with the lines looking like someone threw spaghetti along the frame as well as them leaking because some dink forced the incorrect nut into the aluminum housing. i had a person come in because another shop replaced a brake line and now he's adding fluid every other week. they jammed a standard nut into a metric hole. 26 hundred bucks later it was repaired. all lines were replaced along with the module. there are slight differences in metric and standard lines. slight, but none the less there. they must be taken into account and dealt with professionally. some issues boil down to quality, integrity, pride, and just common sense. after a while it takes no time to make a line to fit like o.e.m. and when a person climbs under their vehicle to look at the work it looks like it did the day it was new. not wire tied and stuffed into place. i now i'm repeating myself using different descriptions and dialogue but issues like this are close to my button. it's like opening a hood and seeing ignition wires that were installed in another shop all wire tied in a bunch because they were the universal fit all. some shops have homer simpsons and fred flintstones working there and it shows.

[Tim Martin]

Steve, aside from the safety and looks issues, you mention the possibility of using compression fittings on brake lines as being illegal. In this country with laws, bylaws, rules, regulations, etc, etc, I can easily believe that. I am wondering if there is a place where I can go to find that out. I'm asking that cause I ain't got a clue where to start to locate legislation like that. Because if it is illegal and I use them and the vehicle I put them on is involved in an accident and someone is injured or even killed and the fault could be traced to a blown out brake line/compression fitting, I am in big trouble, am I not.

[marcdaniels]

Not only are compression fittings on brakes lines dangerous (they are not designed to withstand the extreme pressure of a brake system) Here in New York they are deffinently illegal to the point that a vehicle will not pass a NYS inspection with them. But what it all boils down to with other shops that use them and make the replacement brake lines look like a six flags rollercoster is just pure lazyness and greed. Lets do this as easy and quick as possible and charge the customer for a professional job. Thats what I see here when we get one in for inspection for instance and they just had these lines replaced. Or the DIY'er, one of my guys put himself thru college working at Advance and he always said you would not believe the people that wanted to just install rubber hose and hose clamps on their brake lines. He said you HAVE to sell that to them knowing fair well it won't last a second.

[ricmorin]

There's no specific federal law preventing their use that I know of. In several states with safety inspections they are specifically prohibited. Maine and NY are two. In NH it's a matter of interpretation. I fail them. Most comp fittings are good for 400 psi where some brake pressures would double or triple that.

No go.

[Tim Martin]

While I do not doubt the legitimacy of the statements made so far, has anyone ever seen one of these compression fittings fail? It was stated that these compressions are only rated for 400psi and we all know that most brake systems can put out up to 1500 psi, so potentially they can fail but have you ever seen one blow apart?

[nickscarcare]

I believe that here in Minnesota that compression fittings are illegal. I have never used one on a brake line and never will. I do ocassionally use a union, where I cut and flare the line, but usually try to go from front to rear, or one junction block to another. I have seen sompression fittings come in, and they are not allowed to leave my hands without being fixed properly. I have seen them leak, but thankfully not seen them blow out yet. We have a do-it yourselfer around here that has a "shop" and that is how he fixes lines. About ready to turn him in.

[jbadenoch]

Ive been taught and through experience that unions or full line replacement is the only SAFE way tor repair them. In mass, where I grew up, comp fittings were shunned and pretty sure illegal. Certainly against map standards. Brakes are the MOST important component on the vehicle, why take a chance of losing them? Flaring isn't much more time consuming or really any more difficult. Bob in sc

[wbuxton]

Double flare and be done, or custom bend. There are too many lawyers around. Temporary fix on the side of the road is a substitute for a wrecker and fixed safely. We flare the ends of tranny cooler lines when a customer wants an aftermarket cooler installed.

[ricmorin]

I have never seen one blow out. I've seen them leak, though.

[brianp87]

I havent had to do a brake line in a long time. Maybe 2 years. I only flare when I do.

[mopwrforme]

as you can see with my avatar i love going around in circles at a high rate of speed. part of that is of course much brake going into the corner. i have seen comp. fittings just blow apart i think mainly due to installer error.. having to fab. all the brake lines by hand is the norm. with these type of cars and ive watched back yard stuff come apart on several of them and of course its hello mr. wall. at my shop i will not use them many have touched on the fact that they are not up to dot spec. and in indiana i have to fail a vehical for them. i have worked hard to get where i am and refuse to let something like low quality work go out of my shop that any compatant lawyer could and would own you and everything you have. not even thinking about the sleepless nights when you realize youve just killed someone due to cutting corners. they are not rated for high preasure stuff. they have there use just not for brakes. as far as legal goes if you are a quailified tech. and have been trained then you legally should know that if comp. fittings are dot rated unsafe. and you put it on a car that has problems it really isnt a big leep to the court room. its called liabitity we are responsable for what we put out the door. case in point a good customer of mine has a friend that went to one of the local big chain brake shops they quoted her xxx for a complete brake job after she pickeed her jaw off the floor. she declined the repair and her friend told her about me well they put it back togeather she made it about 5 miles on the interstate and watched as her tire passed her going down the pike well thats not the end of it the tire went into traffic granny run over the tire in the minivan got some air and then had a hart attack. what do you think that outcome will be. who cares if its legal do it right the first time. were not talking about price here its all about quality. sure it takes longer so charge for it,in my shop custom brake line work is actual time ill start with 2hrs and call you if i need more.,... im sorry ill stop its been a long day

[steven kiser]

when a vehicle comes into my shop for a repair and i see compression unions on brake lines i insist that they are removed. i can recall a few times when i've seen them tightend so much the sleeve is twisted and the line is restricted. i've seen a vehicle that the rear feed line has been cut and bent over, crimped so it wouldn't leak and has been that way for a while. i guess nothing amazes me any more. i do get angry when i see something like this and the bottomer thinks i'm the one that's wrong..........................