Non-working brakes.

gnsnprwldwsl · 09-06-2008, 06:32 PM

I bled my brakes at all the calipers.

But my brakes still aren't working.

When I step on the brakes, sometimes they'll work like normal,
but most of the time they'll just sink straight to the bottom
where the wheels would lock if you pressed any harder.

If you stepped on the brakes fast enough, it might work ok,
but it's mostly when you slowly step on the brakes, that the
pedal would just sink to the bottom.

Think you guys might have an idea of what's going on ??

kbrew8991 · 09-06-2008, 09:46 PM

hmm, tough to say without really looking at it / feeling it myself - but I'd look at replacing the master cylinder if I had to take a stab from across the internet

toy-driver · 09-06-2008, 11:24 PM

I agree with kbrew. Master cylinder sounds like the problem.

Gunner87 · 09-07-2008, 12:02 AM

Sounds like the master cylinder... possibly air in the lines but it sounds like the air would be out by now... so I'm voting on the m.c.

gnsnprwldwsl · 09-07-2008, 05:09 AM

Would it be possible that air is in the master cylinder itself and I would have to keep bleeding my brakes until I see air??

Also, would it be possible that the Brake booster be messed up??

Because the brakes would work sometimes and would only lock up at the bottom of
the braking pedal's path...

Gunner87 · 09-07-2008, 09:31 AM

If you bleed the brakes and caught air in the lines because the M.c. ran low of brake fluid then it would be you still have air in the lines. The brake booster could be messed up and is not pulling off the vacuum, the vacuum line may be leaking. Or you may just need to bleed it again and find air in the system...

Its a very hard question to answer over the internet due to I don't know how they feel when the pedal is pressed.

kbrew8991 · 09-07-2008, 10:02 AM

bleed some more if you want - if it spits out some bubbles then you just didn't quite bleed it all the way before and that could be your issue

if it keeps spitting nice clean no-bubble fluid - sounds like an internal seal in the MC is bleeding off pressure and not "activating" the brakes - time to rebuild it or buy a new one (I prefer the latter, usually just a few $$ more after you return your old one to get the core charge back)

dvoth · 09-07-2008, 11:08 AM

Im with all the others, the mc is bad and needs to be replaced.

metheores · 09-07-2008, 11:30 AM

Well, my friend has a similar problem with his RX-7, in order to brake he has to push the pedal to the border line where the tires are supposed to lock (not enough pressure to actually lock em) that's because there's air in the brake booster, but it might also be the MC, but if it were the MC wouldn't the brakes be down at the bottom the whole time? just wondering.

toyotagt_mr92 · 09-07-2008, 12:32 PM

it is the master cylinder i had the same problem change it fer sure

gnsnprwldwsl · 09-07-2008, 05:40 PM

Dang, changing the master cylinder would be a big pain .

Thanks for all your input guys !!

For some reason, I'm really hoping that there's still just air
in the system so that I can just try to get it out.

Would having air in the braking system for a prolonged
amount of time increase the likelihood of this kind of thing
happening though ??

kbrew8991 · 09-07-2008, 06:02 PM

it shouldn't be too bad, just make sure you pick up the specialized line wrenches so you don't round off the fittings

muffinman · 09-08-2008, 04:22 PM

I had the exact same problem in my 86 , some times the brakes worked and some times they went straight to the floor, and i changed the MC but the problem still existed. Recently i flushed all the fluid and found that one of my bleeder screws was blocked. After all new fluid and cleaning the bleeder screw the brakes are working properly again and there is no pedal fade at all.

Gairloch · 09-08-2008, 04:44 PM

Quote:

Originally Posted by Gunner87

If you bleed the brakes and caught air in the lines because the M.c. ran low of brake fluid then it would be you still have air in the lines. The brake booster could be messed up and is not pulling off the vacuum, the vacuum line may be leaking. Or you may just need to bleed it again and find air in the system...

Its a very hard question to answer over the internet due to I don't know how they feel when the pedal is pressed.

You might have something here. OP, are you sure that you didn't suck air in through the master cylinder when you were bleeding?

If you are confident that you didn't suck air in and bleeding the system results in no change then yes, it's got to be the master cylinder. Having air in the system doesn't increase the liklihood of this happening. It's just a matter of wear and tear over time.

You might want to check with Aaron @ Lithia Toyota to see what a MC would run you with the club discount.

gnsnprwldwsl · 09-08-2008, 07:35 PM

Wow, Muffinman !!

Thank you !! That's the best thing I've heard all week !
But it does sound like a big thing to fix if I'm going to have
to flush out all the brake fluid.

Another question .. do brake fluid turn reddish orange over time ??

kbrew8991 · 09-08-2008, 08:32 PM

Quote:

Originally Posted by gnsnprwldwsl

Wow, Muffinman !!

Thank you !! That's the best thing I've heard all week !
But it does sound like a big thing to fix if I'm going to have
to flush out all the brake fluid.

Another question .. do brake fluid turn reddish orange over time ??

after decades it could turn that color as it corrodes all the inner linings of the brake lines

muffinman · 09-09-2008, 09:42 AM

Quote:

Originally Posted by gnsnprwldwsl

Another question .. do brake fluid turn reddish orange over time ??

Mine turned to a dark orange/brown , it's not hard to flush.
Take a small piece of clear hose that fits the bleeder screw tightly and submerge it in a bottle with some fluid in it and then just work your way around the car as some one pumps the brake , make sure you constantly check your MC so that you don't run out of fluid and start sucking in air.

gnsnprwldwsl · 09-11-2008, 04:12 PM

Wow, the master cylinder is really expensive to replace !!

Is there anything else that I might have to check for ??
Could it be that the brake lines somewhere instead be
leaking fluid ?? Any particular trouble spots that I might have to check ??

muffinman · 09-11-2008, 04:16 PM

Quote:

Originally Posted by gnsnprwldwsl

Could it be that the brake lines somewhere instead be
leaking fluid ?? Any particular trouble spots that I might have to check ??

unless the fluid level keeps dropping i don't think you have a leak

kbrew8991 · 09-11-2008, 04:52 PM

Quote:

Originally Posted by muffinman

unless the fluid level keeps dropping i don't think you have a leak

correct - it *has* to go somewhere

where are you shopping for the part? Shouldn't be *that* bad...

09-06-2008, 06:32 PM	#1 (permalink)
gnsnprwldwsl Cage Fighter Join Date: Jan 2008 Location: Los Angeles Posts: 109 Thanks: 4 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Non-working brakes. I bled my brakes at all the calipers. But my brakes still aren't working. When I step on the brakes, sometimes they'll work like normal, but most of the time they'll just sink straight to the bottom where the wheels would lock if you pressed any harder. If you stepped on the brakes fast enough, it might work ok, but it's mostly when you slowly step on the brakes, that the pedal would just sink to the bottom. Think you guys might have an idea of what's going on ??

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09-06-2008, 09:46 PM	#2 (permalink)
kbrew8991 gimme some turns Join Date: Apr 2006 Location: Houston, TX Posts: 1,415 Thanks: 60 Thanked 73 Times in 63 Posts My Google Map iTrader Rating: (4/100% )	hmm, tough to say without really looking at it / feeling it myself - but I'd look at replacing the master cylinder if I had to take a stab from across the internet

09-06-2008, 11:24 PM	#3 (permalink)
toy-driver Getting there Join Date: Oct 2007 Location: Dallas, TX Posts: 265 Thanks: 3 Thanked 12 Times in 12 Posts iTrader Rating: (3/100% )	I agree with kbrew. Master cylinder sounds like the problem.

09-07-2008, 12:02 AM	#4 (permalink)
Gunner87 No Skills Join Date: Aug 2008 Location: Alabama Posts: 35 Thanks: 3 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	Sounds like the master cylinder... possibly air in the lines but it sounds like the air would be out by now... so I'm voting on the m.c.

09-07-2008, 05:09 AM	#5 (permalink)
gnsnprwldwsl Cage Fighter Join Date: Jan 2008 Location: Los Angeles Posts: 109 Thanks: 4 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Would it be possible that air is in the master cylinder itself and I would have to keep bleeding my brakes until I see air?? Also, would it be possible that the Brake booster be messed up?? Because the brakes would work sometimes and would only lock up at the bottom of the braking pedal's path...

09-07-2008, 09:31 AM	#6 (permalink)
Gunner87 No Skills Join Date: Aug 2008 Location: Alabama Posts: 35 Thanks: 3 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	If you bleed the brakes and caught air in the lines because the M.c. ran low of brake fluid then it would be you still have air in the lines. The brake booster could be messed up and is not pulling off the vacuum, the vacuum line may be leaking. Or you may just need to bleed it again and find air in the system... Its a very hard question to answer over the internet due to I don't know how they feel when the pedal is pressed.

09-07-2008, 10:02 AM	#7 (permalink)
kbrew8991 gimme some turns Join Date: Apr 2006 Location: Houston, TX Posts: 1,415 Thanks: 60 Thanked 73 Times in 63 Posts My Google Map iTrader Rating: (4/100% )	bleed some more if you want - if it spits out some bubbles then you just didn't quite bleed it all the way before and that could be your issue if it keeps spitting nice clean no-bubble fluid - sounds like an internal seal in the MC is bleeding off pressure and not "activating" the brakes - time to rebuild it or buy a new one (I prefer the latter, usually just a few $$ more after you return your old one to get the core charge back)

09-07-2008, 11:08 AM	#8 (permalink)
dvoth No Skills Join Date: Mar 2007 Location: Texas Posts: 48 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (1/100% )	Im with all the others, the mc is bad and needs to be replaced.

09-07-2008, 11:30 AM	#9 (permalink)
metheores Supreme! Join Date: Feb 2008 Location: Boston, MA Posts: 683 Thanks: 38 Thanked 16 Times in 16 Posts iTrader Rating: (1/100% )	Well, my friend has a similar problem with his RX-7, in order to brake he has to push the pedal to the border line where the tires are supposed to lock (not enough pressure to actually lock em) that's because there's air in the brake booster, but it might also be the MC, but if it were the MC wouldn't the brakes be down at the bottom the whole time? just wondering.

09-07-2008, 12:32 PM	#10 (permalink)
toyotagt_mr92 mrjonny Join Date: Feb 2008 Posts: 74 Thanks: 7 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	it is the master cylinder i had the same problem change it fer sure

09-07-2008, 05:40 PM	#11 (permalink)
gnsnprwldwsl Cage Fighter Join Date: Jan 2008 Location: Los Angeles Posts: 109 Thanks: 4 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Dang, changing the master cylinder would be a big pain . Thanks for all your input guys !! For some reason, I'm really hoping that there's still just air in the system so that I can just try to get it out. Would having air in the braking system for a prolonged amount of time increase the likelihood of this kind of thing happening though ??

09-07-2008, 06:02 PM	#12 (permalink)
kbrew8991 gimme some turns Join Date: Apr 2006 Location: Houston, TX Posts: 1,415 Thanks: 60 Thanked 73 Times in 63 Posts My Google Map iTrader Rating: (4/100% )	it shouldn't be too bad, just make sure you pick up the specialized line wrenches so you don't round off the fittings

09-08-2008, 04:22 PM	#13 (permalink)
muffinman Brain Surgeon Join Date: Jan 2008 Location: Ft. Lauderdale Posts: 1,804 Thanks: 24 Thanked 102 Times in 99 Posts My Google Map iTrader Rating: (1/100% )	I had the exact same problem in my 86 , some times the brakes worked and some times they went straight to the floor, and i changed the MC but the problem still existed. Recently i flushed all the fluid and found that one of my bleeder screws was blocked. After all new fluid and cleaning the bleeder screw the brakes are working properly again and there is no pedal fade at all.

09-08-2008, 07:35 PM	#15 (permalink)
gnsnprwldwsl Cage Fighter Join Date: Jan 2008 Location: Los Angeles Posts: 109 Thanks: 4 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Wow, Muffinman !! Thank you !! That's the best thing I've heard all week ! But it does sound like a big thing to fix if I'm going to have to flush out all the brake fluid. Another question .. do brake fluid turn reddish orange over time ??

09-11-2008, 04:12 PM	#18 (permalink)
gnsnprwldwsl Cage Fighter Join Date: Jan 2008 Location: Los Angeles Posts: 109 Thanks: 4 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Wow, the master cylinder is really expensive to replace !! Is there anything else that I might have to check for ?? Could it be that the brake lines somewhere instead be leaking fluid ?? Any particular trouble spots that I might have to check ??