General brake question

[tom999w]

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.

 

[Inertia]

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

 

[tom999w]

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.

 

[Dan the man]

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.

 

[Dan the man]

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.

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.

 

[Inertia]

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.

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.

 

[Inertia]

It's better to adjust the brake shoes so that they are just contacting the drums rather than applying the emergency brake.

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

 

[junkyardhero]

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.

 

[RustyRatRod]

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.

 

[RustyRatRod]

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.

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.

 

[junkyardhero]

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.

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?

 

[RustyRatRod]

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?

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.

 

[tom999w]

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.

 

[tom999w]

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.

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.

 

[RustyRatRod]

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.

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.

 

[junkyardhero]

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.

none taken.

for every horror story you've got about "not good mechanics" i've probably got 10 about "not good customers".