brake line replacement

[47silver]

Hi
i am going to rebuild the calipers and replace the rubber brake lines.

What hard lines will break when i dissasemble this 30+ year old system. i am thinking i should just order them now with everthing else..

[James Brown]

they shouldn't break just make sure that you use the proper flare wrench when removing them, and a little lube won't hurt.
but if you do, you can make your own lines with a tube bender and a flare tool, or buy them new.
going with stainless steel braded hoses?

[47silver]

have the ss hose, but wondering if i should get the regular.....

[James Brown]

I think it depends on the quality of the parts more than if they look cool. the old ones are what 25 years old and still hold tremdous amounts of pressure. but that was back in the day when quality ment something. today, who knows where there made and how long the'll last. go with the best ones regardless of type. lots of disscusion on here on hoses. I did mine (rebuld) and man the stock brakes almost pull your teeth out when everything works correctly! Don't leave a 6 pack on the seat when braking!!!!!! now everything gets belted down

[docrodg]

Soak the steel lines with WD40 at the nuts prior to disassembly. Spray the back of the nut and the threads.

Use only a flare nut wrench on them.

You can bend and flare replacements if needed, but the flare is critical and can be difficult to do. Get your line bent and cut then take it to a hose shop that does hydraulics and have them do a double-flare. Their equipment works better.

The SS braid covered lines are not significantly stronger than good quality rubber lines, rubber lines are inside the braid, the braid just helps with bulging that should not be a problem with a good quality line.

The real key to a good brake job is getting everything true and bled well. Measure the run-out of the rotor and mark the high spot with the measurement. When you get the rotor turned have them mount it on the lathe with the runout the same as on the car, viola - zero runout. If you don't match the measurement then any deviation in the suspension knuckle will give you runout when remounted.

Use a pressure bleeder. Our host has them for 40 bucks or so, they give best brake performance.

Torque wrench only on the lug nuts. Run them in at half torque then to full, that will balance the stresses on the rotor and prevent warping.

[mtnfir]

I would use PB blaster and soak the threads overnight to loosen the gunk. THen make sure you use a flare wrench and you won't screw anything up. Sears sells a nice 6 piece metric flare set for like 34 dollars. Well worth the frustration of not having to deal with a regular combination wrench.

[47silver]

thanks for the advice, will let you know how it went.

[cmcfaul]

What’s a flare wrench? How is it different from a regular wrench?

Thanks,

Chris
73 911 E

ps I had a SS front brake line explode on me. luckily it was while I was checking the other side for leaks. Could have been real bad.

[kkinzli]

A flare wrench is crucial for doing the brake lines on a 911 as you will otherwise destroy your hard brake lines. This happens because a normal wrench will only have 2 sides to contact on the nut and since they are made of brass they will deform. The flare wrench basically gives you more contact points on the nut to ensure you don't deform it. Here try this link.

WikiAnswers - What is a solar flare

image here : Google Image Result for http://www.mclendons.com/img/diy/38-flare.jpg

[cmcfaul]

Thanks, having changed the brake lines a couple times the nuts was stripped. I had to use vice grips on at least two to get them off and really butchered them. Now I know why.

Live and learn

Chris
73 911 e

[aj88cab]

Not to state the obvious, but since nobody mentioned it, and just in case, please use two flare wrenches, one on the nut and one on the hard line to keep it from twisting.

[Monza_dh]

I recently did this on my '88 and no matter how many times or how long i soaked the hard lines in PB Blaster or liquid wrench the line still goat mangled removing from the rubber and main lines.

I ended up buying new ones and replaced them with the new rubber lines as well. With rebuilt and cleaned up calipers the brakes look sweet!

[avendlerdp]

Hey- The best way to get frozen brake line fittings apart is to use HEAT. Just a regular propane torch on the line nut and presto, its off. Not a lot of heat, just a little, you don't need to get it glowing or even close, just hot.

Oh, and get a flare nut wrench. You have to use that.

[burgermeister]

1) if you cut the flexible line, you can unscrew it even if the flare nuts are seized to the hard lines

2) if the flare nuts are indeed seized to the hard lines, you can heat them & wiggle them & PBblaster them repeatedly and they will free up. The line will become a neat cannon shooting exploding brake fluid - be prepared.

3) if you're not inclinded for 2), you can replace the outer hard line, and then the inner can stay seized. Thread & tighten the soft line onto the inner, then thread & tighten the new non-seized outer hard line.