General brake question

-
tom999w

tom999w

Well-Known Member
Joined
Mar 30, 2024
Messages
101
Reaction score
72
Location
New York
I have a car (a 2000 XYZ with power brakes, no ABS, disks in front, drums in back) and the front brakes locked up while driving and were smoking. So I replaced the rear brake shoes, rebuilt the front calipers, inspected the front pads (they were new), inspected the metal brake lines (in good condition), and replaced the front rubber brake lines.
So when I went to bleed the brakes, the fluid level in the master cylinder reservoir is not moving at all, the pedal goes to the floor, and the fluid in the reservoir is cloudy. Little to no fluid comes out of the bleeders. I've been trying to bleed the brakes for two days with no results ( tomorrow will be day three).
So my question is: might the car need the master cylinder replaced? I hate to keep throwing parts at it like a mechanic shop would do, because it's getting expensive. But all the symptoms don't point to a faulty master cylinder.
 
The pads/shoes need to be in full contact with the rotors/drums before you start to get "pedal".
So it can take quite a few pumps to move the pads out, then you should be able to get fluid while bleeding.
Set the emergency on, to ease rear bleeding as well, shoes also need to be against drums. All
 
Last edited:
True, the front pads do not expand to press on the disks no matter how many times I press on the pedal. There's a 1/8" space between the pads and the disk.
And the brake fluid in the reservoir never budged.
 
If the fluid level is not dropping it's possible that you could have a frozen brake caliper. The brake fluid being cloudy is can be caused from moisture. When you changed the pads did the pistons in the calipers move easily? The master cylinder could be leaking internally between the front and rear reservoirs.
Click to expand...
 
Inertia said:
The pads/shoes need to be in full contact with the rotors/drums before you start to get "pedal".
So it can take quite a few pumps to move the pads out, then you should be able to get fluid while bleeding.
Set the emergency on, to ease rear bleeding as well, shoes also need to be against drums.
Click to expand...
If the fluid level is not dropping the pads will not make contact with the rotors as disc brakes adjust by the fluid level, as the pads wear the fluid level goes down. It's better to adjust the brake shoes so that they are just contacting the drums rather than applying the emergency brake.
 
tom999w said:
True, the front pads do not expand to press on the disks no matter how many times I press on the pedal. There's a 1/8" space between the pads and the disk.
And the brake fluid in the reservoir never budged.
Click to expand...

The front brakes not releasing is concerning, as both calipers seizing at same time isn't likely, so pressure not releasing is likely.
Now the pump/master cyl doesn't appear to be able to make pressure, so is suspect.
I've had contaminated brake fluid cause rubber seals to swell, blocking a master cyl port, causing similar, on a motorcycle as well.
 
Dan the man said:
It's better to adjust the brake shoes so that they are just contacting the drums rather than applying the emergency brake.
Click to expand...

I disagree, to a degree.
It's always nice to have well adjusted brakes, - when bleeding, if you move the shoes into contact with the drum with the emergency, you eliminate any wasted pedal travel moving the shoes out, especially if they are out of adjustment. The wheel cylinder struts move out, stay out cuz the emergency is stopping the springs pulling the shoe back and forth.
Suggesting a novice adjust the rear brakes thru the slot can prove challenging to someone not familiar to adjusting, and can be out and out frustrating, if not impossible to un-adjust if over-tightened, ya know, - holding the lever away with one hand and screwdriver, - while backing-up the star, with the other hand with a tool, third hand holding a flashlight, allll thru that tiny slot, - meanwhile the drum won't turn.
The emergency is so much more time efficient, and less likely to cause anyone the annoyance if messing with the adjusters unnecessarily.

jmexperience
 
Last edited:
sounds to me like the seals in your master are waster OR you've got a clugged line someplace.

25 years is pretty good service life out of a master, replace it and see where you're at.
 
A good mechanic shop wouldn't have thrown parts at it. They would have done some diagnosis. Can you tell us what diagnosis you did and the results? That might help us narrow down the cause.
 
junkyardhero said:
sounds to me like the seals in your master are waster OR you've got a clugged line someplace.

25 years is pretty good service life out of a master, replace it and see where you're at.
Click to expand...
I had issues once a long time ago getting fluid to the rear brakes on a car we had on the shop. I kept going up the system from the rear until I got to a brass junction block about mid ways up the frame. Get this. There was a small pebble stuck in the double flare opening of the rear line where it screwed into that brass block. Simple procedure. Just go up the system until you find pressure and you'll find the problem.
 
RustyRatRod said:
I had issues once a long time ago getting fluid to the rear brakes on a car we had on the shop. I kept going up the system from the rear until I got to a brass junction block about mid ways up the frame. Get this. There was a small pebble stuck in the double flare opening of the rear line where it screwed into that brass block. Simple procedure. Just go up the system until you find pressure and you'll find the problem.
Click to expand...
wild. you think that was a chonk of some detritus that broke off from inside upline somewheres? or a foreign object introduced to the system during a fluid top up or something?
 
junkyardhero said:
wild. you think that was a chonk of some detritus that broke off from inside upline somewheres? or a foreign object introduced to the system during a fluid top up or something?
Click to expand...
No it was not metallic in any way. It was 100% a pebble. We theorized that maybe it got in on someone's fingers on a previous repair.
 
The front pistons were movable, the guide pins were normal, and the rubber boots were good. I checked, cleaned, and lubed all the movable parts. I'm thinking the master cylinder is not moving the fluid the short distance through the front metal line, then the front flexible hoses, then the front calipers, to be able to expand the pads onto the front disks.
 
RustyRatRod said:
A good mechanic shop wouldn't have thrown parts at it. They would have done some diagnosis. Can you tell us what diagnosis you did and the results? That might help us narrow down the cause.
Click to expand...
No offense to any mechanics on here, but I'm 54 years old and have found only about two "good" mechanics in my life. But I can tell lots of horror stories about "not good" mechanics. There should be a mechanic horror story thread, for people that like to gripe about that sort of thing.
 
tom999w said:
No offense to any mechanics on here, but I'm 54 years old and have found only about two "good" mechanics in my life. But I can tell lots of horror stories about "not good" mechanics. There should be a mechanic horror story thread, for people that like to gripe about that sort of thing.
Click to expand...
I'll be 60 next year. I started in 1974 like an idiot when I was nine. I've been retired from a disability for a while now, but I still piddle around with my own stuff when I feel good enough. The number of stories I hear almost daily pisses me off about the level of "service" people get......especially with our older cars. They are slap easy to work on, yet everybody acts as if they take some kinda special voodoo to work on.
 
tom999w said:
No offense to any mechanics on here, but I'm 54 years old and have found only about two "good" mechanics in my life. But I can tell lots of horror stories about "not good" mechanics. There should be a mechanic horror story thread, for people that like to gripe about that sort of thing.
Click to expand...
none taken.

for every horror story you've got about "not good mechanics" i've probably got 10 about "not good customers".
 
Nothing is more annoying than searching the internet for a hour looking for an answer to a problem, and then finding the perfect thread but then the OP never follows up with the solution. So here is the solution to this thread for future surfers that may encounter this same scenario: I changed the master cylinder today and now all the brakes operate normally. Thanks everyone for their input.
 
tom999w said:
Nothing is more annoying than searching the internet for a hour looking for an answer to a problem, and then finding the perfect thread but then the OP never follows up with the solution. So here is the solution to this thread for future surfers that may encounter this same scenario: I changed the master cylinder today and now all the brakes operate normally. Thanks everyone for their input.
Click to expand...
Glad that you got the problem resolved. I thought that was the problem.
 
tom999w said:
Nothing is more annoying than searching the internet for a hour looking for an answer to a problem, and then finding the perfect thread but then the OP never follows up with the solution. So here is the solution to this thread for future surfers that may encounter this same scenario: I changed the master cylinder today and now all the brakes operate normally. Thanks everyone for their input.
Click to expand...
i don't get my answers from fortune cookies.
 
junkyardhero said:
i don't get my answers from fortune cookies.
Click to expand...
You're right. But the reason I'd posted this thread in the first place was because I've read lots of people with similar symptoms, and they just threw money at it, changing all kinds of parts, with no fix. So I was trying to zero in on the next component that may need replacement without wasting too much $$. I've replaced master cylinders in the past which did not fix the brake problem. But in the end everything is ok and everyone's happy.
 
tom999w said:
You're right. But the reason I'd posted this thread in the first place was because I've read lots of people with similar symptoms, and they just threw money at it, changing all kinds of parts, with no fix. So I was trying to zero in on the next component that may need replacement without wasting too much $$. I've replaced master cylinders in the past which did not fix the brake problem. But in the end everything is ok and everyone's happy.
Click to expand...

My apologies, back at post 6, I mentioned that the pump didnt appear to be working.
The next sentence I typed suggested replacing the MasterCyl.
I do remember typing it, but it's not there.
I have often wished I had a "erase" button after an entry. lol
Now I need to figure out which key that was .
Glad it worked out, cheers
 
tom999w said:
You're right. But the reason I'd posted this thread in the first place was because I've read lots of people with similar symptoms, and they just threw money at it, changing all kinds of parts, with no fix. So I was trying to zero in on the next component that may need replacement without wasting too much $$. I've replaced master cylinders in the past which did not fix the brake problem. But in the end everything is ok and everyone's happy.
Click to expand...
glad you got it sorted.

you maybe didn't need to do the whole encharito with the rest of the system, but if you've got a bad master and the rest of is has been maintained about the same the chances are it's time for a once over on all that too.

sometimes working on cars is looking for lost keys. they're always in the last place you look.
 
RustyRatRod said:
I'll be 60 next year. I started in 1974 like an idiot when I was nine. I've been retired from a disability for a while now, but I still piddle around with my own stuff when I feel good enough. The number of stories I hear almost daily pisses me off about the level of "service" people get......especially with our older cars. They are slap easy to work on, yet everybody acts as if they take some kinda special voodoo to work on.
Click to expand...
What I like is watching complete morons on YouTube telling you how to do something on a car when they are completely clueless. I see a lot of that when I watch videos on body work and / or painting. I am a hobbyist at body work and painting, but over the years I've gotten pretty good at it. Some of the stupid stuff I see those morons doing makes me crazy. I wonder how many people have watched their videos and were lead down the wrong path.
 
tom999w said:
No offense to any mechanics on here, but I'm 54 years old and have found only about two "good" mechanics in my life. But I can tell lots of horror stories about "not good" mechanics. There should be a mechanic horror story thread, for people that like to gripe about that sort of thing.
Click to expand...
None taken, I've probably worked with 10× as many bad techs as You could tell stories about, some of them are My age or older.....I marvel at how they could possibly have made it this far being that F'n awful, but then I see the equally awful writers & managers who suck & are sympathetic enablers, & then it becomes clear.....
 
It's the same in my field, architecture. Young UNEDUCATED idiots are being hired and producing complete garbage. But when I dig into the cause of this problem, it's because they're being managed by young EDUCATED idiots.
 
You must log in or register to reply here.
-

Back
Top