New brake lines leaking at fittings

Finally got around to testing my brake lines that I've installed into the 84 Bronco. Some I made myself, others are pre-made legnths from O-reilly's Auto Parts. I bench-bled the master cylinder, and let gravity flow take the fluid down the lines as much as possible before try to bleed the system. No leaks at all four wheels, but some of the tee-fittings and unions leaked like mad. How tight should the connections be? I snugged them all up beforehand, but not past the point where the nut felt like it stopped, maybe 10 ft-lbs max. The two lines I custom-made appear to have a low-quality double flare as compared to the pre-made lines, so I plan to replace them with the pre-made. But two of the connections on the pre-made also leaked . Any suggestions for better quality hard lines? Or should I invest in some more braided steel flex hoses? I have two of those, one for each axle drop. JSM84

JSM- i think the connections should be no tighter than 10-15 ft lbs, i think thats how tight mine are. as far as the leaks at the unions, i have never done this, have you thought about teflon tape at the threads? Have you tried looking at classic tube products? I ended up going with braided lines on my axle drops and had no problems.

I went with Russel & Goodridge parts when I built my Mustang & Grand National but they're a bit pricey and I didn't go that route when I started building trucks. I've run into the same problem with being able to produce good quality double flares at home, particularly when using stainless lines (almost a necessity up in New England). What I ultimately wound up doing was purchasing lengths of pre-flared stainless and then cutting & bending them to fit. I always use Swagelok unions to marry the lines (I was introduced to Swagelok stuff when I was a commercial diver & in hyperbarics) because there simply *isn't* a better quality tube fitting available anywhere at any price (Parker brand fittings are a reasonable alternative when you can find them in stainless). Just be sure to get the 316 stainless fittings regardless of whether or not you're using stainless or carbon steel lines since compression fittings should always be harder than the tubing (you *can* get away with buying stainless ferrule sets to use in carbon steel or brass bodies. With Swagelok at least, don't know if Parker sells ferrule kits or not). For some reason every compression fitting that I've ever seen or gotten from an auto parts place has been brass. With compression fittings in general and Swagelok's in particular you tighten the nut as much as you can by hand & then go an additional one & a quarter turns with the wrench and you're done. I've always gotten my fittings from a local Swagelok dealer (it's always *city name* Valve & Fitting, you might have one nearby) but I'm sure you can order them direct. Goodridge is showing set of pre-bent lines for $92. The Swagelok fittings aren't cheap but the price isn't excessive either (again you can save some cash and buy brass, alloy or carbon steel bodies and just use stainless ferrule sets) but you simply won't find a better quality fitting.

http://www.russellperformance.com/

http://www.raceshopper.com/goodridge_brake_lines.shtml

http://www.swagelok.com/

http://www.swagelok.com/search/product_det...x?part=SS-400-6

T-tape won't help w/compression fittings. The threads only serve to swage the ferrule onto the line and to force the ferrule into the fitting body which is what creates the seal. I've also used braided lines for extensions when installing lifts, never had a problem with them. I've never had a problem using pre-flared lines & compression fittings either.

Basic info on the Swagelok fittings:

http://www.swagelok.com/EN/SYN/10858/product_detail.aspx

Justshootme84 said:

Finally got around to testing my brake lines that I've installed into the 84 Bronco. Some I made myself, others are pre-made legnths from O-reilly's Auto Parts. I bench-bled the master cylinder, and let gravity flow take the fluid down the lines as much as possible before try to bleed the system. No leaks at all four wheels, but some of the tee-fittings and unions leaked like mad. How tight should the connections be? I snugged them all up beforehand, but not past the point where the nut felt like it stopped, maybe 10 ft-lbs max. The two lines I custom-made appear to have a low-quality double flare as compared to the pre-made lines, so I plan to replace them with the pre-made. But two of the connections on the pre-made also leaked . Any suggestions for better quality hard lines? Or should I invest in some more braided steel flex hoses? I have two of those, one for each axle drop. JSM84

Click to expand...

TEFLON Tape! It'll seal the threads! Yup. Damn, never mind someone beat me to it!

Lil StompeR said:

TEFLON Tape! It'll seal the threads! Yup. Damn, never mind someone beat me to it!

Click to expand...

No, Teflon tape won't seal the threads. Not on compression fittings anyways (or AN/JIC type fittings either the threads on these types of fittings don't see fluid, they're designed to compress one half of the fitting into the other & the interface between the fitting halves is what holds pressure), see the last part of my previous post /emoticons/[email protected] 2x" width="20" height="20" />

Are the fittings that are leaking brass like you get at the auto parts store ? IF so that's most likely the problem since the brass ferrules are softer than the steel lines they'll never swage on properly & you'll never get a tight seal.

Thanks, BB78, I'll look into getting some better fittings and check on the SwageLok brand. The lines I'm using are steel, not stainless. The unions and tees are brass. I'm thinking that both those and the fitting ends I got from JEG's are the problem, as much as my poor-quality double-flares. I got to where 3 out of 5 attempts looked decent, while the other two were off-center. So if the fttings are at fault, I maty be able to keep my homemade lines. I made one for the rear drop from the MC to the proportioning valve, since that has different sized fittings on each end. (3/8" and 7/16"). I am using Russell's braided steel hoses for the axle drops, then teeing off to each wheel. The rear tee is fine, but the front one leaked. I replaced it with another one and it still leaks.

I also agree that I can't use Teflon tape or any kind of thread sealer for brake lines. My Dad said that the 'cheapie' brass fittings and couplers I'm using are the likley culprit, too. (paraphrased, of course). I didn't want to spend $180 on a compete set of new hard lines, but that may end up being the result. Having good brakes is naturally a big safety concern, even on an offroad only rig that's rock crawling. I've got to get this problem solved before ican fire up the engine again and take the Bronco for a test drive.

Thanks for the replies, JSM84

Yea teflon tape wont do much of nothing for ya there, might actually hurt by not letting you tighten the fitting down to the point where the two ends get compressed together. I've had good luck with small plumbing compression fittings on brake lines before. ****, I've even sweat soldered them together like plumbing pipe.

Make sure you have the parts well aligned before tightening the fittings, you can force them to fit a little crooked with very minimal effort, and then leaks are plentiful. I usually snug them up and wiggle the connection a bit to make sure it's properly aligned.

I don't know that I'd trust my brakes to a soldered joint, not even a silver soldered one. /emoticons/[email protected] 2x" width="20" height="20" /> The Swagelok stainless fittings are good to 11,000psi and are only a few bucks apiece so that's why I like to use them.

Well I dont know what to say about this post except I hope none of you ever get in an accident and hurt someone with compression fittings or soldered brake lines because if they inspect the vehicle after the crash you're probably going to prison if you killed the person . These kinds of joints have absolutely no place in an automotive brake system although the swagelock fittings metioned are very good if installed properly they are still a compression fitting and DO NOT belong in this system . The double flare joint is the only fitting allowed in the automotive brake system for safety reasons obviously they cannot blow out of the fitting . Also brass has no place in a hyraulic system capable of this kind of pressure . I have seen lines blow off at work because some idiot put a brass or black pipe fitting in a hydraulic circuit and it blew up . Under pancic stops the hydraulic pressure can get to or exceed 2000 psi most brass fittings are only good for a couple hundred pounds . Heres some links to read through . Please do not offer that advice to new people do it right or do not do it you dont want to have hurting or killing someone on your concience trying to save a couple dollars . I know in the sate of Michigan for instance if your truck is over the legal height limit and you hurt or **** someone your doing jail or prison time would be the same for an unsafe vehicle with a repair like that . /emoticons/[email protected] 2x" width="20" height="20" />

http://action.publicbroadcasting.net/carta...ist/575009.page

http://www.pirate4x4.com/forum/showthread.php?p=9490119

http://www.familycar.com/brakes.htm

http://action.publicbroadcasting.net/carta...list/84411.page

While I can appreciate the comment, and this is not in fact an attempt at being contentious, I'm just not seeing how this is different from any other aspect of working on your own truck. If someone decides to install a 9" lift using nothing but taller springs the bump-steer will make it very dangerous to drive, front lift blocks do the same. The guy who decides to "tighten up" his steering box by cranking down on the steering gear pre-load ***** or the person who doesn't properly tighten his calipers down and loses one. Obviously it's everyone's responsibility to either do the work safely, pay someone else who can or park the vehicle.

Stainless Swagelok fittings are good to considerably more than the bursting pressure of stainless lines (6000PSI) and low-carbon lines (3500PSI). Properly installed the system will not leak or blow out. Simple as that. The Swageloks easily exceed the pressure rating of the braking system. Double flares are the industry standard because they're safe *enough* to take the rated pressure and they're cheap to install & maintain not because they're inherently superior. If the proper materials are used & the installation is correct stainless lines w/Swageloks exceed the pressure rating of the factory hydraulics. While I'm sure we've all seen poorly installed compression fittings it isn't rocket science, finger tight then one & a quarter turns with a wrench. No more, no less. Scribe a line on the body & nut and you can't get it wrong.

Now I'll grant that it may be a bad idea for *everyone* to run out & try it, exactly because of the experiences you relate, someone is bound to grab a brass fitting w/brass ferrules and try it out (Swagelok brass *bodies* have a 4000PSI pressure rating so when used with stainless or low-carbon ferrules (to properly swage onto the line) they still exceed the burst rating of standard low-carbon lines) but if someone who is aware of the facts and knows what he's doing chooses to go this route the system is no less safe then what was on there to begin with. The problem will always be with those who try to cut corners, are misinformed, or have poor work habits. I agree with your thoughts on soldered lines but was simply being polite.

No unsafe information was provided (by me at least, I cannot take responsibility for the thread as a whole) . The correct materials were referred to as well as the correct installation practices and manufacturers specs & info were referenced with links provided. It's no more of a burden to my conscience than if I tell someone how to install a lift & they fail to torque down the bolts resulting in a loss of control. I didn't elaborate any further than I did because JSM84 strikes me as the kind of guy who can turn a wrench & do it safely if given the necessary information.

checking out http://www.familycar.com/brakes.htm what I read there was "You must never use brass "compression" fittings or copper tubing to repair a brake system. They are dangerous and illegal." From what I'm reading this confirms what I said in my post, that brass wouldn't work (a brass *body* will work but you must have ferrules that are harder than the material your brake line is made of, a distinction I specifically made and that was made only in reference to Swageloks)) I assume the illegal reference is to brass fittings as well but without a citation or knowledge of what state we're talking about it's hard to know.

http://www.pirate4x4.com/forum/showthread.php?p=9490119 provides no specific or verifiable info either other than to correctly note that Swagelock's are not actually compression fittings but are in fact tube fittings. Swagelok's use a different 2-piece ferrule design than standard compression fittings. I should have made that distinction clear initially, I'm just used to calling them compression fittings. Specifically, Swagelok's are 2-ferrule/mechanical-grip type fittings. My bad.

http://www.swagelok.com/fittings/proper_se...ourceIdlt=33840

Neither of the other pages addresses the issues that I posted about. Admittedly the former state inspectors said they'd be reluctant to pass a vehicle with compression fittings but Swagelok's aren't compression fittings and I believe the intent of both their statements and the applicable laws is to keep people from using substandard parts to repair vehicles & by substandard I'm meaning parts that will cause the system to not function correctly or have a lower margin of safety than designed neither of which is an issue with what I discussed. The issue with compression fittings comes down to their pressure rating, pure & simple. Swagelok fittings have pressure ratings that far exceed the working or bursting pressure of factory braking systems & it's hard to see how that compromises safety. Hydraulic systems are one of Swagelok's intended applications, they're designed and patented to do this & to do it better than double-flared fittings. Yes, they *can* be installed incorrectly and that will compromise safety but you can say the same thing about any brake, suspension or steering work that someone chooses to do at home rather than pay a shop for and that possibility doesn't stop us from offering advise about those issues either.

Clearly this is a difference of opinion & I hope my post comes across as respectful. As I said, I'm not trying to be contentious and I honestly don't want to repeat or revisit past issues that I've had to apologize for. I'm honestly just not seeing the point. The fittings are rated far in excess of the system bursting pressure if installed correctly and I didn't think for a moment that JSM84 wouldn't be able to do that. My advise to someone I was unsure of would have been different.

If I can remember to do it this weekend, I'll take some pics of what i have and where the leaks are. One of the fittings that doesn't leak is the factory brass tee on the rear axle, where the single line drops from the frame to the tee, then splits off to either side thru hard lines to the wheel cylinders. I know that is fine to use, because it is a factory part. I have a similar-type tee for the front Dana60 axle, except it's from O'Reilly's and not sure of the brand. It leaks on both ends where the hard lines fit into it. The hardlines are either the pre-made ones with ends already on them, or ones I made with the double-flare kit and ends from JEG"S. I believe those lines and ends from JEG's to be of inferior quality, as well as their DF kit. HEck ,even the pre-made lines may be of poor quality? That's the subject of this post - the questionable quality of auto parts store brake lines and accessories. Along with that is my vain attempt to make my own lines, even with older ttols that my Dad has used for years as a professional mechanic. I do have his advice to keep me safe. I will check out those links y'all posted and do some further research. JSM84

Bill I just wanted to make it a point that compression fittings are not the correct answer. I agree with you that swage locks are a very high quality product we use them at work and I have them in the fuel system on my own truck,s . They do have to be installed correctly though if you just put the tube in and tighten down then they are nothing more than a compression fitting there is a special tool for them called a swedgeing tool that actually cuts a groove on the tubing being used that the first ferrule then crushes down into that groove causeing the mechanical lock and yes it probably would never let go but I would not take the chance a double flair just cant get back out of the fitting . /emoticons/[email protected] 2x" width="20" height="20" />

True, I've used the pre-swaging tool myself but never on anything smaller than 1" lines (or maybe 3/4" when using thickwall low-carbon or stainless). Your tubing has to be cut square & has to be inserted until it bottoms out or you'll short-stub it and have leaks but I've never had a problem completely swaging anything smaller than 1/2" (including stainless) by hand and having a good swage that can be safely disassembled & reassembled. A properly swaged ferrule ain't slipping out thru the nut /emoticons/[email protected] 2x" width="20" height="20" /> For that matter a gauging tool is only a few bucks and guarantees you've properly tightened the fittings (assuming of course it isn't short stubbed)

I had meant to attach a copy of the handbook with the original post since it provides all the correct installation & usage info as well as a lot of good information about stainless & carbon-steel lines. It's good stuff to know even if you aren't using the fittings.

swagelok_handbook.pdf

My battery was dead in my camera, so no pics. But I replaced the 3 lines that I had made myself with new, pre-made ones from Advanced Auto. I really had to tighten down the fittings on the lines where they connected to the union and front tee, but finally stopped the leaks. I figured at least 25 ft-lbs. of torque. One rear line was clogged where it was bolted into the old wheel cylinder before replacing thos with new ones recently. Just had to unbolt that line and blow it out with the air hose, then it was clear. The front bleeder screws were stubborn, and I ended up having to use Vise-Grips to remove them. Both sides were clogged with debris or rust. After bleeding all four corners twice, I now have a good, firm brake pedal. And dry connections!!! JSM84