Replace rubber brake lines, yea or nay?

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02FailBlazer

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2002 TB LTZ, 4WD, 198K miles.

Overhauling my brakes soon, wondering if I should replace the rubber brake lines. Pretty sure they're all original. I don't have any reason to believe any of them have failed or are seriously deteriorated, this would be a purely preventative measure. Is it worth the extra money and effort?

This has been a California car its whole life, and an inland one at that, so there's as little rust and deterioration as you could ever reasonably expect for a 24 year old vehicle. Things are generally in good shape.
 
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By "overhaul my brakes" are you meaning pads and rotors and all calipers and master cylinder? If you are doing all that, do the lines. Especially if you plan to keep the TB.

Your screen name makes me feel that you have had some bad times with the TB. Are you on the other side of all that and gonna keep it? If you are not keeping the TB, doing the lines will not get you more money but most certainly save you some headaches. Afterall, the wear and tear of the brake lines is usually on the inside, especially in the climate you are in.

Are you doing the steel lines and rubber hoses or stainless braided hoses?
 
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And they're not overly expensive. You could get yourself all 4 for under $100. I also vote change 'em.
 
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movietvet said:
By "overhaul my brakes" are you meaning pads and rotors and all calipers and master cylinder? If you are doing all that, do the lines. Especially if you plan to keep the TB.

Your screen name makes me feel that you have had some bad times with the TB. Are you on the other side of all that and gonna keep it? If you are not keeping the TB, doing the lines will not get you more money but most certainly save you some headaches. Afterall, the wear and tear of the brake lines is usually on the inside, especially in the climate you are in.

Are you doing the steel lines and rubber hoses or stainless braided hoses?
Click to expand...

Wasn't planning on doing the master cylinder or calipers, just pads, rotors, fluid change, and slide pin boots since those are cheap and easy. It's never leaked brake fluid and I looked the steel lines over whenever I had the chance to get a close look and I haven't found any areas that looked really concerning, cars last forever out here.

I'm keeping the TB, but it's a second car now and is being relegated to severe weather/off-road/backup use, it's not a daily driver anymore. I just want it in reasonably reliable, drive-able condition, doesn't need to be perfect.
 
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02FailBlazer said:
Wasn't planning on doing the master cylinder or calipers, just pads, rotors, fluid change, and slide pin boots since those are cheap and easy. It's never leaked brake fluid and I looked the steel lines over whenever I had the chance to get a close look and I haven't found any areas that looked really concerning, cars last forever out here.

I'm keeping the TB, but it's a second car now and is being relegated to severe weather/off-road/backup use, it's not a daily driver anymore. I just want it in reasonably reliable, drive-able condition, doesn't need to be perfect.
Click to expand...
Overhauling brakes means something different to me. But I also was in shops for 40+ years. Your overhaul is "friction materials replacement with a fluid flush added on. I have always felt that the brake system on ANY vehicle, is the single most important system. Don't care about the other systems but when you apply the brakes, it BETTER stop.
 
Small update - before putting in a parts order I was checking a few things and there's a hiss when pressing the brake pedal to the floor. See video. Thoughts? No codes, brakes feel the way they have for the past 10 years.

Video link here.

You can hear me depress the brake pedal near the beginning and release it at the end. Phone was held over the dash in front of the steering wheel, couldn't pinpoint a source for the sound.
 
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flyboy2610 said:
Sounds like the brake booster to my tired old ears.
Click to expand...

That's what I suspected after a quick search, just wanted some confirmation. Guessing it needs to be replaced? Looks like the only new one available is from SKP, hopefully it's decent. Will I need anything else to do the replacement?
 
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02FailBlazer said:
Small update - before putting in a parts order I was checking a few things and there's a hiss when pressing the brake pedal to the floor. See video. Thoughts? No codes, brakes feel the way they have for the past 10 years.

Video link here.

You can hear me depress the brake pedal near the beginning and release it at the end. Phone was held over the dash in front of the steering wheel, couldn't pinpoint a source for the sound.
Click to expand...
Yea, brake booster. You can hear an initial "whoosh" sound when you apply brakes with a vacuum booster but continuous noise like that, IMO, indicates a vacuum leak that is leaking at the inside firewall. If you pinch off the vacuum feed to the booster, engine running, and then hold brake pedal again, the noise should not be there. When you pinch off and hit pedal, it will also feel hard, like you hit the brakes without the engine running. Want to be sure the new one does not make that noise.

In your case, the brakes likely felt normal but as it would get worse, the pedal would have gotten harder over time.
 
I remember my 02 had mushy brakes and that whoosh noise. Was told at the time this was normal despite multiple brake bleeds. Apparently the aluminum calipers allowed more movement or stretch and allowed the pedal to go down to almost the floor. Now my 07 with cast iron calipers aren't mushy and don't have that whoosh noise because I can't get the pedal down enough to do it. Could be the reason they stopped using aluminum calipers in the front.

Try gently pinching the front caliper rubber hoses with hose pinchers and see if the pedal firms up and stops the noise.
 
Check out In Line Tube for the lines/hoses.
 
Pinched off vacuum hose to brake booster, brakes firmed up to near rock-solid feel and the hiss was gone. Guessing that confirms the booster is bad.
 
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Failing now/going bad and hard pedal before long when it leaks enough.
 
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New question - Any recommendations on what brand/type of vacuum hose to buy to replace or make spares for the brake booster hose? I looked for direct replacements and there aren't any.
 
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@02FailBlazer I replaced the booster years ago on my 08 because it was failing and 1 thing I did forget to order is the gasket between the firewall and booster. It was totally toast and I had to make up my own gasket.
 
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Parts will all be here soon, want to make sure I've got the process right.

Parts being replaced - vacuum booster, master cylinder, front/rear rubber brake lines, rotors/pads, front caliper brackets (exchanging to perform EXT brake upgrade), front/rear slide pin boots

Process -
  • Replace vacuum booster and gasket
  • Bench bleed new master cylinder, replace old master cylinder
  • Separate calipers from brake lines, replace slide pin boots
  • Replace rubber brake lines
  • Reinstall calipers
  • Replace pads/rotors
  • Bleed brakes/do brake fluid change, starting at rear right and working forward

Does this look right? Do I need to do anything special when bleeding the brakes, like engaging the ABS system to bleed it?
 
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For the EXT brake upgrade :thumbsup:

For the brake bleeding, as long as you don't have air in the system to begin with, it should be fine doing a normal brake bleed/flush. The order is RR, LR, RF, LF

Be sure to use actual brake lube for the pins. I like the ceramic type, usually purple or orange, but the regular silicone type is also good.

Be sure to clean the surface of the wheel hub down to clean metal. Brake jobs can get ruined just by having some rust under those new rotors.
 
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Mooseman said:
For the EXT brake upgrade :thumbsup:

For the brake bleeding, as long as you don't have air in the system to begin with, it should be fine doing a normal brake bleed/flush. The order is RR, LR, RF, LF

Be sure to use actual brake lube for the pins. I like the ceramic type, usually purple or orange, but the regular silicone type is also good.

Be sure to clean the surface of the wheel hub down to clean metal. Brake jobs can get ruined just by having some rust under those new rotors.
Click to expand...

Inland Cali checking in, what is "rust"?

Jokes aside, sounds like I'm set. Got Sil-Glyde for brake lube, seems commonly recommended. I'll stick with the standard bleed procedure and see what happens. Going to do the one-man "bottle" method - run clear tubing from the bleeder into a bottle filled part way with fluid placed above the caliper, work the brakes with a block of wood under the pedal to flush air/old fluid out, and keep the master cylinder topped off with fresh fluid.
 
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Only thing with the one man method is that I would wind up with some air in the caliper as air would get sucked in through the bleeder screw's threads when you let go of the pedal. One thing I did was remove the bleeder completely and put some teflon tape on the threads, screw it back on part way, bleed and then close the bleeder.

Another way would be to use a vacuum pump, an oil pump or what this guy used.

 
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Hopefully your old one is reusable. I think it is just a rubber piece. I think you have to be conscious of the thickness if making one as this could affect the rod to brake pedal distance.

And I also remember this thread although no resolution came from the OP regarding the rod or "pill" in the booster that pushes on the master cylinder being too long:
R

Thread '04 trailblazer, brakes dragging after new pads, calipers, master cylinder'

So, I took my TB to a guy who does my auto work to get the brakes improved. I had like they were a little weak and I tow my camper with it, so wanted it right for spring.

he pulled all pads off, and odd thing, he told me both front calipers froze and even with clamps he couldn’t push them out. (Made no sense to me cause he said they were not froze when he test drove)
So he did 4 sets of new pads, 2 front rotors, and a master cylinder. Not sure if it was new or rebuilt but I think it was aro7 d $160 for the MC
He also told me he had a hard time bleeding them, and he replaced all the...
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This one was kinda resolved:
https://gmtnation.com/forums/threads/oreilly-reman-brake-booster-adjustment.21779/

Be sure you keep an eye on this and verify that the pill doesn't push on the MC when the pedal isn't pushed. Might have to reuse the pill from the old booster.
 
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