Help! Brake Lines Leaking at Flares (1 Viewer)

[Will Van]

I am following this excellent write-up on the ABS/LSPV Delete, and I cannot get the lines to stop leaking at the master cylinder t-fitting, or the 90* fitting at the driver's side rear axle. I have disconnected them and cleaned them with brake cleaner several times. I have used both the OEM T-fitting and an aftermarket Earl's Performance T-fitting (both M10x1.0 inverted flare). I don't want to over-tighten the fittings, but I'm still not sure why they won't stay dry.

Does anyone have any suggestions? Is there a tool specifically designed to clean the flare mounting surface?

 

[CruiserIRL]

Could be some residual paint/coating stuck in there or dirty threads preventing them from sealing up. A wire brush and a pipe brush should get it cleaned out.

 

[ZackR]

When you reassembled after cleaning were the fittings dry? I found its better if they are lubed a bit with brake fluid. You also might need to tighten them a bit more.

 

[CruiserIRL]

When you reassembled after cleaning were the fittings dry? I found its better if they are lubed a bit with brake fluid. You also might need to tighten them a bit more.

Use a flare wrench, also.

 

[ZackR]

Use a flare wrench, also.

One of the best tools I ever bought was a nice set of flare wrenches. Invaluable for brake line work.

 

[CruiserIRL]

You definitely can get them much tighter with a flare wrench. They usually start to strip as you snug them up with a spanner. I had air in my clutch line after rebuilding the master because I didn't have a flare handy. Turns out a little 1/4 turn with a flare from that point and the leak stopped for good. I hope it's as easy for you here. Also, I would just make sure as you tighten each flare nut you are holding the brass fitting with a crescent or something so not to tweak or loosen the other connections.

 

[NV1971FJ40]

I had the same problem. I just cranked on them hahah

 

[ajax1]

Use a flare wrench, only thing I’ve used to clean lines is piece scotch brite and sometimes a jewel file on threads. Prob just need to tighten more

 

[Will Van]

I have a flare wrench.

 

[Saito]

Could it be a bubble flare tee ? And you’ve got inverted flare fittings ?

 

[Saito]

Ah. Never mind.

 

[LandCruisinMy93]

@Will Van go to Autozone and get the metric flaring loan a tool and hit the end of the offending lines with the tool. You may need to true up the existing flare, or if it still wont seal, redo the flares and try again. If you tried using the Earls M10x1.0 it was probably a bubble flare fitting and screwed your inverted flares so they wouldn't work with the stock fitting.

 

[Will Van]

@Will Van go to Autozone and get the metric flaring loan a tool and hit the end of the offending lines with the tool. You may need to true up the existing flare, or if it still wont seal, redo the flares and try again. If you tried using the Earls M10x1.0 it was probably a bubble flare fitting and screwed your inverted flares so they wouldn't work with the stock fitting.

Here is the Earl’s fitting I used. I don’t think it’s a bubble flare fitting. It says inverted flare.

What are the specs on the OEM brake flares? 37 degrees? I want to make sure I get the correct flaring tool.

Also, the other 90 degree fitting is OEM Toyota. So it’s definitely not a bubble flare fitting, but it’s still leaking.

 

[bigredmachine]

if you have enough line I would cut the end of the line off and reflare it.

 

[Will Van]

if you have enough line I would cut the end of the line off and reflare it.

What are the specs on the flare? Japanese double flare at 45 degrees? Or 37 degrees?

 

[bigredmachine]

that im not sure, but I have this flaring kit at work
www.gearwrench.com/gearwrench-41880d-combined-double-bubble-flaring-tool-kit.html
. as per their description the kit does 45 degree flares, ive had to make lines for my truck and they haven't had any issues sealing unless I made a bad flare

 

[flintknapper]

What are the specs on the flare? Japanese double flare at 45 degrees? Or 37 degrees?

Automotive flare is always 45°. Should be double flare.

Some applications (don't know about the Land Cruiser) can be bubble flare (usually only found on European Cars).

 

[LandCruisinMy93]

What are the specs on the flare? Japanese double flare at 45 degrees? Or 37 degrees?

As mentioned it should be a 45 degree AFAIK. All I can say is, if the Earl's fitting is in fact a inverted flare fitting, you may not have lined it up good enough when tightening the lines and may have screwed the flare up. I have deleted the LSPV/ABS and have also screwed around with hydroboost. The metric double flare loan a tool at autozone worked for me. Making new flares isn't difficult if you just take your time to do them right. The biggest problem you'll run into and cause yourself when doing any kind of brake work is not making good connections. If your lines don't naturally fall on the cone of the connection or very close, you will try to tighten the nut down and it will tighten but the connection is off kilter and you just screw the flare seal. Think of it like you're tightening a cone into a cone shaped socket...as self aligning as you think it should be...its not. It's easy to tighten that cone into the sidewall of the socket 8f you're not cautions, possibly gouging the sidewall or otherwise not creating a true seal. You have to make sure that the brake lines are nice and perpendicular to the connection point as you cinch the nut down. Then once there is no more freeplay in the line, then you tighten it.

 

[JeepinPete]

@LandCruisinMy93 how do you like hydroboost on the FZJ80 brake system?

 

[flintknapper]

I didn't read the thread in the link you provided but I have this question:

1. Are you reusing certain lines and fittings? I didn't see you mention purchasing any lines or making any flares in existing lines?

The reason I ask....is you might check and see if the 'flare' type is different on the ABS end as opposed to the flare type at Tee's, Unions, Master Cylinder.

It is possible the flare for the ABS could have bubble flares (depending on where it was manufactured).

Also, check to see what type of tubing nuts are used. There are basically two types:

1. Fully threaded nut.
2. Threaded nut with a non-threaded 'lead'. The 'lead' is right before the flare in the tubing.

You don't want to thread one into a fitting designed for the other.