Question in the title. I'm redoing the Datsuns original brake lines in NiCopp and have a bunch of lines flared that I think are "good enough", but I would hate to get the entire system together and find they all leak. Is there a simple way?
Question in the title. I'm redoing the Datsuns original brake lines in NiCopp and have a bunch of lines flared that I think are "good enough", but I would hate to get the entire system together and find they all leak. Is there a simple way?
PSI is PSI. Put a cap on one end, put a gauge and air fixture on the other. Apply pressure, measure for leaks. Dunk under water or spray with soapy water if you think there is one.
Brakes make up to 2000psi, the only effective way is to just go for it, really.
Pete. (l33t FS) said:Brakes make up to 2000psi, the only effective way is to just go for it, really.
Yea, this. If anything is wet, you lost.
berkeley yeah. Alright, I'll slap it all together and see where it leaks.
I have a telescopic hood prop.
When I finish bleeding a system, I pump up the brakes and wedge it between the steering wheel and pedal overnight.
It's not leg pressure but it's enough to find a leak by morning.
If what you want to prove is that you did not do a bad flare, then make a dead end fitting and apply 100 psi and put the end in a pail of water.
Bet that if the flare holds at 100 it will hold at higher pressure. 100 psi bubbles are apparent.
If you are worried about making good flares, buy one of these:
I tossed my other brake line flare tool as useless after trying one of these.
In reply to NOHOME :
That looks like a great tool, and shockingly affordable. I have made a bunch of flares that I think look good, but they're not factory quality and I've not done other lines before so I don't quite know how perfect they need to be vs "good enough".
I have an air cylinder brake setup I used when I tow my jeep behind my motorhome- ties into air brake system of the motorhome.
I used that setup with a timer & hook to shop air. 5 seconds on, 5 seconds off. It allowed me to proof the new flared fittings on my race car, calibrate the pressure sensors, bleed the brakes, etc.
I just set it up and let it pump the brakes 500 times looking for leaks...
When you are assembling the lines, don't just tighten the fitting once. Get your flare nut wrench on, snug it down, back it off 45 degrees, snug it down, back it off, snug...You don't have to get carried away with tightness, you are just bedding stuff in. Once the wrench stops turning a bit farther with each swing, you should be good.
I've found that's a good practice even when using factory lines.
Yup
I have found that brake flares are pretty forgiving. If they seem okay they will be, and every flare that has leaked (which isn't many) I thought looked pretty questionable and I knew I should have redone it. The ni-copp lines make it even better because the softness makes them flare and seal so much easier.
I guess my point is if the flare looks ok just put it on the car.
classicJackets (FS) said:In reply to NOHOME :
That looks like a great tool, and shockingly affordable. I have made a bunch of flares that I think look good, but they're not factory quality and I've not done other lines before so I don't quite know how perfect they need to be vs "good enough".
I just finished my "hopefully" last brake job and have this tool (or one of the Amazon equivalent versions) if you want it I will toss it to you for however long you want it if you pay shipping both ways. Should end up half price I would think. It's for 3/16" (4mm) line.
Although it appears you may be done already.
If anyone else reading is currently tackling a similar job, save yourself time and money and do not buy the flare tool from Harbor Freight. Shouldn't even be allowed to exist. I broke two kits back to back just a couple months ago and I was only flaring copper not steel. With a good kit it's pretty straight forward. Check for burrs and knock them down without introducing any flat spots.
In reply to Olemiss540 :
That's a super nice offer. I got most of my new system slapped together last night - need to bench bleed and install the master to check. If they look bad, I might take you up on this!
ClassicJackets-I'm local to you (Beverly Hills, MI) and have the turret style flaring tool if you'd like to borrow it.
NOHOME said:If what you want to prove is that you did not do a bad flare, then make a dead end fitting and apply 100 psi and put the end in a pail of water.
In 30 years of being a hoser this is how we test metal hose assemblies. There are better tests (hydrostatic, nitrogen) but this is the basic test and it works well - the larger hoses might only see 50-70psi.
If you really need to check the hardlines, get a spare master cylinder a few fittings, a cap, or even put a caliper at the end of the line with a block to clamp. Heck, you could mock up every bit of it off the car if you are running all new stuff. Overkill, maybe? It seems like a good idea and could save a bunch of headaches.
wheelsmithy (Joe-with-an-L) said:Yup
At least half the system was working. 
+1 on that tool. Easy enough to do it even on the car if it comes to it.
https://grassrootsmotorsports.com/forum/grm/novel-and-affordable-brake-like-flare-tool/180562/page1/
My advice for it is to not tighten down the tool TOO MUCH on the line you're working on, it will crease the line and screw things up. It's otherwise foolproof, as promised
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