Tips for removing stuck brake lines from the MC?

[Bmachine]

More great info! Thanks so much guys.

Now, when using the torch, at what point do you start worrying about fire?

I usually put a blanket and then some kind of spark resistant material like all foil on top of that. Fire extinguisher at the ready of course. And good ventilation.

Anything else you guys do?

 

[Gary Knox]

I have had great success with Kroil products, especially their Penephite, which is the Kroil with graphite added. They also have a product with silicone - Silicroil that is good as well.

 

[Bmachine]

Success at last!

After two days of Kroil penetrating oil, two different flare nut wrenches, what finally did the trick was the dQ "do the nut" tip. I used a hard rubber mallet and whacked the wrench a couple of times forward and then couple of times backwards and all 3 stuck ones finally came loose. The propane torch and fire extinguisher I just bought this morning obviously scared the bejesus out of those nuts and they relented.

Thank you all for your help!

Pics: Me and my buddy John performing surgery. Ironically the MC is the must corroded part of this whole car. Finally gone.

 

[restart]

Here is another to add to the list. Maybe some of you aircraft folks are familiar with mouse milk? A bit pricey but I recently heard some good stuff about this....
https://www.mousemilk.com/

FWIW there are a number of forums that quote this informal test of force required to turn a nut:


Penetrating oil ..... Average load
None ..................... 516 pounds
WD-40 .................. 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench .... 127 pounds
Kano Kroil ............ 106 pounds
ATF-Acetone mix....53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic transmission fluid and acetone.


I've had good luck with Liquid Wrench as it appears to be quite effective and easy to get in spray form. I've been curious to try the acetone mix but have never gotten around to it.

 

[deQuincey]

this is extremely interesting

i have removed the brake lines from the calipers satisfactorily, no problem using the flare nut wrench, ok

but i no not dare to remove the flexible hoses, as i have to deal with a flexible mount point that does not allow me to make force against a fix and steady point, i must use two wrenches a normal one and a flare nut one
my attempts had proven to be unsuccessful so far applying regular force, so i have not tried further

used ATF+Acetone soaking the nuts for a while but nothing changed

question : do you recomend using a torch ? if so, where do i point the flame ?

i am seriously worried about heating anything to red colour there, those nuts are some kind of soft alloy, and the hoses aren´t steel neither (IMHO)

please advise

regards

 

[m5bb]

its been a while since i have done this - but what i did was heat up the line, then put a flare nut wrench on it - then hit the top of the wrench with the palm of my hand in sharp blows.

This works. Even use a small hammer to hit the wrench. I know it sounds scary but the impact gets the nut loose.

 

[Sean Haas]

PB Blaster overnight, flare wrench and a torch worked for me.

 

[dang]

With enough room you could always try the flare nut wrench with vise-grips on the wrench to squeeze it tighter. :eek:

 

[mulberryworks]

this is extremely interesting

i have removed the brake lines from the calipers satisfactorily, no problem using the flare nut wrench, ok

but i no not dare to remove the flexible hoses, as i have to deal with a flexible mount point that does not allow me to make force against a fix and steady point, i must use two wrenches a normal one and a flare nut one
my attempts had proven to be unsuccessful so far applying regular force, so i have not tried further

used ATF+Acetone soaking the nuts for a while but nothing changed

question : do you recomend using a torch ? if so, where do i point the flame ?

i am seriously worried about heating anything to red colour there, those nuts are some kind of soft alloy, and the hoses aren´t steel neither (IMHO)

Years ago I was trying to remove the flexible lines from my '54 Beetle after it had sat in a field for several years. The rubber lines themselves were cut so I wasn't worried about hurting them. I was heating the steel connector at the hard line junction with an oxyacetylene torch because with a small tip the flame is smaller and easier to control in addition to being hotter than propane. The hotter flame gives you faster differential expansion, which can break the rust loose faster. Sheet metal shields can protect paint.

I hadn't realized that the rubber line was fully plugged so when I heated the connection with the torch I got a very positive result in the hose exploding off the connector with a bang. Hard to say if that was water that expanded or residual brake fluid. Fortunately, I had the welding goggles on. I still had to heat the connection further as it had been quite a while since those two were apart. I replaced the old rusty hard line as well since heating things that much will affect the temper of the steel, something to worry about more with fasteners than brake lines.

 

[Cornishman]

De Q. I had the same issue, after ages of thinking about how to do it just replaced the metal pipes, hoses and then the metal pipes upto the servo's. It is diffent with RHD to your LHD but I am sure you can manage it. Your car is so perfect it deserves new brake pipes and braided hoses.
If you don't have a pipe bender you could use different size cans for different radius curves.
I bought a low cost pipe cutter from Toolzone, just like my home plumbing one but smaller and a minimal cost. Lastly I bought a Draper flaring tool, pipe and fittings online. I used pieces of rubber tube to encase the new metal pipes wherever they are attached to body. Whilst doing this I replaced the oil rubber plugs on the inner wing that the pipes are routed through. Make a note of which pipe goes to which place on the servo and do one side at a time so that you can check how the other side is routed.
The downside is with all that new pipework bleeding is difficult, so I bled it all twice, drove it for a while then did it again. It seems that air sticks to the sides of new pipework more than that which has used and remains wet.

 

[nosmonkey]

I often find staring menacingly at the offending nut with a large lump hammer and cursing does the trick.

Whilst waiting for penetrating oil to do its magic, I also highly recommended shearing some kind of bolt as a sacrifice to the car gods to increase your chances.