brake line install...dumb question

jasonlee · 04-09-2010, 08:08 AM

Just received new stainless brake lines from our host to replace the old rubber flex lines. Here comes the dumb question...is there anyway to install said lines without having to bleed the brakes afterwards? I am guessing probably not, but it never hurts to ask. Thanks in advance.

Gunter · Gunter's Garage

Jason,

It's academic. Do you have the Bentley Repair Manual? If not, get it.

I am worried about you.

First, why SS lines.?? The OEM rubber lines are fine, good for 20 years + and are much easier to install than SS which are trickier and don't flex as much.

Is it also time for a caliper rebuild? meaning: are the pistons frozen? Can you push them back easy? If not, they're frozen. (rusted)
Are the rotors o.k. ? meaning: measure them with a vernier in 4 different places because they can wear uneven.

Bleeding is easiest with a low-pressure speed bleeder. Do a search.

eauboy · eauboy's Garage

If you first submerged your vehicle in a swimming pool-sized vat of brake fluid you could probably change out the lines without introducing air into the system, but then you would have issues with your paint job.

Bleed the brakes after installing the new lines; it is a chance for you to ensure there is fresh fluid in the brake system. The Motive bleeder system works very well for me.

Mitch Leland · Mitch Leland's Garage

Jason,

Bleeding brakes isn't that hard and yes you'll have to do that once you remove the old brakes lines and open the system to the atmosphere (air). However as mentioned above maybe you should be looking further than just the brake lines. If you're not prepared to evaluate, replace the pads, either surface or replace the rotors, rebuild the calipers and replace the fluid with new, I don't think I would just replace the brake lines.

If your entire brake system has been inspected by a "professional" and he only recommended you replace the brake lines, then that's a different story?

BTW, I disagree with Gunter. I think old rubber brake lines can break down inside with some particles of rubber falling down into the pathway acting like a check valve, where as the S.S. line has a teflon liner and is less likely to breakdown. The downside to S.S. lines is the exterior jacket is like a hack saw if it rubs up against any other lines or wiring.

jasonlee · 04-09-2010, 10:36 AM

thanks for the advice. I knew the answer before I asked, however sometimes people have some tricks to share. Not concerned about the callipers or rotors. They move in and out without issue. Rotors are fine as I replaced them not long ago. Reason for SS brake lines, well my OEM are original to the car, so I bought new ones. I like SS, I also bought some super ATE blue and a power bleeder. So actually had every intention of bleeding the brakes. Just wondering if there any tricks.

I have read all the stuff on bleeding the brakes. Doesn't sound hard, but more of a PITA as it were.

Thanks again.

bkreigsr · 04-09-2010, 10:37 AM

brace the brake pedal down a couple of inches to seal off the 'out' valve in the master cylinder. you shouldn't lose more than a couple of drops from each line.

btw, it's a good idea to make sure all the fittings can be loosened on all four corners before you start. you might have to soak a few for a few days with pb blaster or kroil.

if that fails, carefully dremel off (run a slit down one side) the offending hose fitting, as you have new ones waiting to go in.

Bill K

sig_a · 04-09-2010, 06:12 PM

Quote:

Originally Posted by Mitch Leland

Jason,

.........I think old rubber brake lines can break down inside with some particles of rubber falling down into the pathway acting like a check valve, where as the S.S. line has a teflon liner and is less likely to breakdown. The downside to S.S. lines is the exterior jacket is like a hack saw if it rubs up against any other lines or wiring.

--------------------

Just replaced four 23 year old original 911 rubber brake lines, and slit the old lines lengthwise to inspect for what I thought would be weak, pitted, degraded passageway. Nope--no apparent wear or deterioration whatever. SS lines are more about bling than performance or safety. DOT approved rubber brake lines are at minimum performance equals.

dshepp806 · dshepp806's Garage

I stay with rubber (factory).

I guess the braiding would add a layer of protection from things "hitting" the lines....

I've no need for "bling"......

Doyle

Carrerax · 04:32 AM

IMHO, SS lines are better than original rubber (especially old original rubber). Not just bling. They DO De-laminate and deteriorate. They also expand under pressure. If you have ever driven a car on the track with and w/o SS lines there is Def a difference in feel. You may not feel it driving to the Cars and Coffee but if you actually drive your car hard and on the track there is a difference. That said, if you drive your car hard and dont want SS at least buy new OEM rubber lines. I have seen old lines fail and it isnt pretty. I have also seen SS lines fail on racecars first hand and highly suggest only using the highest quality ones. Do not buy them based on price. The diff between the cheapest and the most expensive isnt that much $. Just my $.02
PS, I dont want to make this a discussion on the best kind of lines. Everyone has their own opinion. Mine is based on many years racing experience.

mthomas58 · 05:55 PM

Quote:

Originally Posted by Gunter

Jason,

Bleeding is easiest with a low-pressure speed bleeder. Do a search.

I'm right behind you. My new stainless brake lines were delivered by FedEx 20 minutes ago! I am also rebuilding the calipers and replacing the flex line to the slave cylinder (noticed it was weeping a little on connection up by the slave)

I fabricated a DIY pressure bleeder using my shop compressor at 15 psi connected to a length of clear 3/16" ID tubing. Pull off reservoir overflow tube and attach low pressure line from the compressor. (be careful not to use too much pressure or you will mist brake fluid out through the center hole of the cap - ask me how I know). You should also have a water filter on your compressor (compressed air contains water and brake fluid will absorb it) This method for bleeding works great!

Good luck.

Gunter · Gunter's Garage

Quote:

Originally Posted by jasonlee

thanks for the advice. I knew the answer before I asked, however sometimes people have some tricks to share. Not concerned about the callipers or rotors. They move in and out without issue. Rotors are fine as I replaced them not long ago. Reason for SS brake lines, well my OEM are original to the car, so I bought new ones. I like SS, I also bought some super ATE blue and a power bleeder. So actually had every intention of bleeding the brakes. Just wondering if there any tricks.

I have read all the stuff on bleeding the brakes. Doesn't sound hard, but more of a PITA as it were. Plus some surprises in not getting the pedal to feel hard.

Thanks again.

Soak the old fittings generously with real penetrating oil (NOT WD-40) and use quality wrenches to counter-hold and open the fittings. No cursing allowed.

Women want to know if the the 911 has SS lines before accepting a ride.

And paint the calipers; red or silver is popular.

Enjoy.

jasonlee · 04-10-2010, 12:19 PM

no cursing allow? That may prove to be easier said than done. SS lines are as important for w woman to accept a ride as the envy impressive parking brake slide (of course never attempted in the 911 no would it be)

holtjv · 04-10-2010, 05:21 PM

Quote:

Originally Posted by Gunter

Soak the old fittings generously with real penetrating oil (NOT WD-40) and use quality wrenches to counter-hold and open the fittings. No cursing allowed.

Women want to know if the the 911 has SS lines before accepting a ride.

Enjoy.

Grumpy today, Gunter?

Do you have bias ply tires on your 911? Women want to know.