brake reservoir sediment (red mud, rust, ???)

[brucecooner]

The Heartbreaker gave me a great big holiday surprise today.

 

Two questions.

 

What is red mud in the brake fluid reservoir a sign of?

What is green fluid in the brake fluid reservoir a sign of?

(pictures below)

 

The story so far...

I finally started on the brake booster replacement today.

Everything was going well until I figured out the booster probably wasn't coming out with the reservoir/cylinder in place.

I guessed they tend to get replaced as a unit.

So I figured I'd undo a couple of fittings, deal with the mess, and bleed the system, which I was wanting to do anyway.

Before loosening any fittings I figured I'd drain the brake fluid reservoir so I didn't have a large spill on my hands.

 

I got a little plastic cup and started bailing the large side of the reservoir.

The fluid was clean looking at first, if a bit red, but as I started  getting to the bottom of the reservoir I started pulling up red mud from the bottom. 

Uh oh.

The other, smaller side of the reservoir yielded green fluid. 

 

It's like Christmas inside there.

Or, as my son described it, cajun and wasabi.

Or maybe red and green salsa.

 

Whatever it is, I'm guessing it shouldn't be in the brake fluid reservoir.

 

 

 

 

Yuck.

The red is probably rust?

Maybe the system took in a lot of water at some point?

 

So at the least a new reservoir/cylinder is in order, but I'm wondering about the further ramifications of what I found.

Would I expect this crap to be in all the lines?

All the way out to, and into the calipers?

 

Would this call replacing all the lines and calipers?

Or would a solid flush be sufficient?

If it's a sign of water, I'm guessing you don't want to keep any of the old hardware in the system.

 

And related question.

The brake line fittings on the reservoir do NOT want to break loose. I rounded a corner of one fitting.

(odd note: one of the fittings is 7/16ths and the other is 1/2 inch)

However neither would the fittings down on the prop valve break loose either.

My fear is that the rust has invaded all the fittings.

I spritzed them with some penetrant and left them to think it over.

Any advice on getting the lines loose without breaking things?

 

 

 

 

 

 

[AZJeff]

Good brake fluid is clear, with a slight tinge of a yellowish color, but certainly NOT green or brown (or any other weird color.)

 

It seems that your brake system is contaminated with something besides plain brake fluid.  Since your plan is to remove the master cylinder from the booster, you might want to consider making the plunge to put a new master cylinder on the vehicle while you are at it.   They are not that expensive, and with a new one, you know the start of the system is not contaminated.

 

As far as getting the fittings loose from the MC, if the car lived it's life in AZ, a "flare nut wrench" will keep the chances of rounding the hex shape on the nuts to a minimum.  If that STILL seems to be likely, then I vote for heat from a propane torch next, to break up the rust between the nut and the steel line.   The area around the MC has lots of room, so the chances of burning your MJ to the ground are slim, as long as you use some thought before waving the torch over anything and everything.  (I have used the torch method to loosen fittings on cars that lived in corrosion central, better known as N. Illinois, when I lived there years ago.)

 

Once you have the new MC installed, and begin the bleeding process, if the fluid fails to run clean after a significant amount of fluid has been pumped through the system (1 quart or more), then maybe it's time to consider replacing wheel cylinders and calipers as needed.

 

Funky brake fluid will attack and damage all the parts of the system, especially anything with rubber seals that slide.

 

Sorry.....

[brucecooner]

59 minutes ago, AZJeff said:

Funky brake fluid will attack and damage all the parts of the system, especially anything with rubber seals that slide.

 

Sorry.....

Yeah, my fear is that whatever this is has gotten to the seals in everything all the way out to the wheels.

My greater fear is that it will have affected the lines themselves, which will make for a very yucky experience.

 

I was already wanting to replace the cylinder/reservoir, but was going to put if off and do the booster alone.

I had foolishly hoped the booster could be done without having to loosen a fitting, alas it was not to be.

 

I do like your idea.  New cylinder, start from there.

And look for that specific wrench, and hope I don't have to flambe any fittings.  :)

[gogmorgo]

Looks like old brake system junk. Most older vehicles have at least a little crud in the bottom of every reservoir. Might also be some dust that got into the system. 
What is a thing is that brake fluid used to be colourful. Back in the day when you changed your brake fluid you would put a different colour in. That way you knew when you’d got all of the old fluid bled out of the system. Red and blue were the most common colours I believe. I’ve definitely seen old brake fluid come out of a vehicle that had an orange or greenish tinge. Both in the same vehicle is probably unusual, but if you don’t know the maintenance history… ¯\_(ツ)_/¯
 

I would just clean out as much of it as you can. Once you’ve got it back together make sure the system is fully bled with good clean fluid. If it worked just fine before you swapped out the booster, it very likely will still work fine with new fluid. If it gives you peace of mind to swap out the master cylinder it’s probably worth doing to prevent yourself from worrying, they are generally cheap enough.

[AZJeff]

11 hours ago, gogmorgo said:

Looks like old brake system junk. Most older vehicles have at least a little crud in the bottom of every reservoir. Might also be some dust that got into the system. 
What is a thing is that brake fluid used to be colourful. Back in the day when you changed your brake fluid you would put a different colour in. That way you knew when you’d got all of the old fluid bled out of the system. Red and blue were the most common colours I believe. I’ve definitely seen old brake fluid come out of a vehicle that had an orange or greenish tinge. Both in the same vehicle is probably unusual, but if you don’t know the maintenance history… ¯\_(ツ)_/¯
 

I would just clean out as much of it as you can. Once you’ve got it back together make sure the system is fully bled with good clean fluid. If it worked just fine before you swapped out the booster, it very likely will still work fine with new fluid. If it gives you peace of mind to swap out the master cylinder it’s probably worth doing to prevent yourself from worrying, they are generally cheap enough.

That part you state in bold is something I have never encountered, and I have been working on cars since about 1970.

I wonder if that was that just a Canadian thing (?)

[gogmorgo]

41 minutes ago, AZJeff said:

 

I wonder if that was that just a Canadian thing (?)

I first heard about it from Eagle, so no. It is possible though that it hung on for a lot longer up here. I’ve never personally seen it on shelves, but my 2001 Jimmy’s brake fluid definitely came out green. Murky for sure, but distinctly green. I never had issues with the rubber components in that vehicle’s brake system other than torn caliper pin boots. 
 

While trying to find a date that it quit being the case (I was unable), I noticed Autozone’s diy website says: “Brake fluid is usually a clear, amber, bluish, red, or greenish color when it comes out of the container and it’s new in the system.” https://www.autozone.com/diy/brakes/brake-fluid/what-color-is-brake-fluid
 

I’ve been using the same brand of brake fluid for the last five years or so, and it’s on the amber side of yellow, but like anything else it must vary between manufacturers depending on what their magic formula is. 
Obviously I can’t know whether or not Bruce’s brake fluid is or isn’t contaminated, but I do know I’ve found a bunch of different colours in the brakes of the junk I drive, and everything still works fine. Almost everything I’ve worked on with old murky brake fluid in the reservoir also has a bunch of sludgy sediment in the bottom. In my mind it’s just evidence of poor maintenance history, not changing or bleeding the brake fluid regularly. 

If everything is still working I don’t see any sense in changing out components. But the procedure for contaminated brake fluid involves changing everything with rubber parts. Wheel cylinders, calipers, any valves in the middle of the system, everything. Not just the master cylinder.

 

[AZJeff]

Interesting.....I admit my forays into major brake system repairs were not steady through my years of working on stuff, since I am not a pro and strictly DIY.    All I can say is that, over the years, I never saw anything but the almost clear (straw?) colored stuff, and then the cruddy brown/rusty/icky stuff I removed.

 

Good to know about this.....THANKS.

[cruiser54]

Carry on. Don't worry. Bleed the system well.

 

When I tracked my supercharged Miata, I used Motul Blue and Gold fluid alternately. Like gogmorgo stated, you can tell when the new stuff has filled the system. 

[gogmorgo]

If you’re bleeding out old murky brake fluid, you also know when you’ve hit new fluid. ;)

[cruiser54]

I love simple!! LOL

[brucecooner]

13 hours ago, cruiser54 said:

Carry on. Don't worry. Bleed the system well.

 

When I tracked my supercharged Miata, I used Motul Blue and Gold fluid alternately. Like gogmorgo stated, you can tell when the new stuff has filled the system. 

That's a good idea, switch colors as an indicator when flushing.

That Miata  must have been tons of fun on twisty mountain roads. Did you have it in AZ, and if so did it ever see White Spar Road?

 

I did make some progress today.

With some proper line wrenches, the 1/2 inch fitting broke pretty easily, but the 7/16th did NOT want to turn. 

I spritzed some more penetrant on the the fitting and heat cycled it with a heat gun a few times.

I rapped it with a ball peen hammer a few times for good measure too and it finally turned, but not without some rounding off.

 

I went ahead and picked up a new master cylinder this weekend, but...

The fittings and lines that came out are pretty grody (pictures below), and since I half-rounded the smaller one I'm thinking I should look into a new solution there.

Is it easy to get replacement lines to go between the cylinder and prop valve?

Can you just get like, six inch braided jobs (with correct size fittings of course) or is bending my own and attaching fresh fittings the only way forward?

 

Of course with the master cylinder out it wasn't too awful hard getting the new booster in, despite the contortions involved reaching those upper bolts. 

A small victory, but at least I kept the "parts to install" pile at the same size.

 

 

 

 

[cruiser54]

I've been driving White Spar Road for 43 plus years. 

[brucecooner]

15 hours ago, cruiser54 said:

I've been driving White Spar Road for 43 plus years. 

You lucky devil. 

I call Wickenburg to White Spar Road the "back way" to Prescott.  Beautiful scenery without all the lights and traffic on SR69.

 

I bet you get to go over the Black Hills on 89A to the Verde Valley whenever you want too. 

That descent from Mingus to Jerome always stretches my eyes open, one of my favorite few miles of road.

 

I've gone a few times the "back back way" to Prescott, up to SR 96 and over to Iron Springs Road. 

Stunningly beautiful drive, but a relatively empty corner of Arizona with awesome views and empty roads.

 

 

[cruiser54]

I'm blessed to live where I do in so many ways. 

[Eagle]

On 11/26/2022 at 12:54 PM, gogmorgo said:

I first heard about it from Eagle, so no. It is possible though that it hung on for a lot longer up here. I’ve never personally seen it on shelves, but my 2001 Jimmy’s brake fluid definitely came out green. Murky for sure, but distinctly green. I never had issues with the rubber components in that vehicle’s brake system other than torn caliper pin boots. 
 

 

I don't think you heard that from me, because I've never seen colored brake fluid (except the DOT-5 silicone I use, which has a very faint bluish tinge to it), and I don't remember ever posting anything about colored brake fluids.

[DirtyComanche]

Green can be from copper corrosion.  My GMC was like that and did some digging, it turned out to be somewhat normal for old fluid in them.  I left it alone until I replaced all the calipers.

 

Any hydraulic system will tend to build up some gunk over time.  Things wear, corrode, deteriorate, etc and that winds up in the fluid, along with anything introduced when people open the reservoir to check the level or add.

[brucecooner]

Out of morbid curiosity I stuck a pick into the lines.

I got this green gunk out of the rear brake supply (front of the cylinder).

Could be old crusty brake fluid I guess.

 

The front line (rear of cylinder) actually didn't seem to have any gunk in it, weird given the amount of red mud in that cylinder chamber.

 

The top fittings were....okay, and the lines weren't corroded or rusted, but I had half rounded one of the fittings, so with some more applications of penetrant and the heat gun, and holding the block very tightly in my giant channel locks, I did manage to get these two lines free from the block.

The lower fittings are.....ew.

 

 

Whatever the gunk is doesn't seem to have attacked the lines or the brass (?) fittings.

They seemed to clean up okay.

 

The block has some crud around the fitting ports, which I intend to get out, somehow.

No idea what it might look like inside.

 

 

I have zero desire to pull that block out though.

I'm pretty sure you have to disassemble the entire front half of the truck to get to those lower fittings and given how tight the ones I've freed are it's gonna be a pain.

If it'll live on with a good flush, I am perfectly fine with that.

 

I kind of want to replace these two main supply lines though. At least the one that now has a nicely rounded fitting.

I'm not above getting a kit and practicing flaring.  Partly out of curiosity, to see if I can.

 

 

I've debated deleting the load sensor, and this might be the time to do it, but I'm not sure how big a job that is, and I want to get this guy back on the road (I miss driving it).

 

Having the load sensor doesn't bother me but I'm wondering, are they prone to going out at 30+ years of age?

 

 

 

 

 

 

 

[cruiser54]

Brake-Kleen

[gogmorgo]

19 hours ago, Eagle said:

 

I don't think you heard that from me, because I've never seen colored brake fluid (except the DOT-5 silicone I use, which has a very faint bluish tinge to it), and I don't remember ever posting anything about colored brake fluids.

Huh. Don’t know why I thought that then. Weird. Sorry to put words in your mouth. It was definitely someone on here though 

[brucecooner]

Sorry if you guys thought you were finally rid of my antics.

Everything was moving along until whatever health issue has been nagging me for the last two years decided to knock me out, so I was mostly bedridden through the end of the year.  I'm still not operating at 100%, but I do what I can.

 

 

On the brake front, I finally got to bleed everything, two and a half times because Comanches are special *grumble*.

I got it out on the street and found out I have slightly less brakes than before.  I don't think the rears are pulling their weight.

To top it off after a couple of blocks the brake pedal went toward the floor and I heard a hissing noise again. 

The booster sort of "sucks" the brake pedal to the unengaged position, but when you get past a point, the brake pedal falls down and you hear a vacuum leak.

It doesn't leak as bad as the one it replaced, so I guess that's a hollow victory.

 

So job 1 is procuring a new booster.  I'm just going to return this one by tossing it through the front window of the store where I got it and get another brand. 

Cruiser sounds like a broken record but he's right, they really don't make 'em like they used to.

 

As well, the rear brakes are a little crusty. 

If I'm trying to restore braking function, I really should do something about them.

The hardware's not in horrible shape, but maybe new cylinders and shoes at the minimum.

Also given the gunk I found in the rear chamber of the old master cylinder, new cylinders are probably a good idea anyway.

 

The front calipers are fairly clean and I know they're grabbing good (the smell when I got out last time I drove it told me as much) so not as worried about them.

 

Fixing the rears would probably fix my stopping problem, but I've decided I just don't trust the distro block or the rear prop. valve.

During the bleed, I never saw the dash light come on to indicate the bypass valve had shuttled (and I did clean up the brake light connector while I was installing the new master cylinder.  Goodness knows if the valve is stuck in place or what's going on in there.

 

I have NO clue how well that rear prop. valve is or is not doing it's job.

I'd also like to be intimate with every inch of brake line under there, and not have to bleed it TWO AND A HALF TIMES whenever I work on the brakes.

 

I've started figuring out how I THINK the layout goes, based on my interpretation of various threads here and elsewhere,

and have made up a totally naive starting point, which will get refined.

I still have lots of questions around the rear end, so my plan is to drop the spare and reverse engineer

the current line layout for clues about fittings and such.

In this diagram I assume it's hose line from the rear tee to the wheels which is probably not the case.

 

 

On a scale from boneheaded to dumb*ss I give this a 60% chance of success.

I got some brake line and a flare tool to practice with though. 

 

So currently trying to run down Dana 44 rear brake drum stuff.

 

Way it goes here lately, I'll probably get sick again and be taken down for a while.

Then in  a month or two when I encounter another giant setback on what started as a simple brake booster replacement, I'll post again.

 

 

 

[cruiser54]

I just eliminate all that crap and install an adjustable prop valve for the rear circuit. 

Brakes work way better. 

[brucecooner]

8 hours ago, cruiser54 said:

I just eliminate all that crap and install an adjustable prop valve for the rear circuit. 

Brakes work way better. 

That is absolutely what I'm after. 

 

My diagram didn't make it clear, but that is an adjustable prop. valve on the rear line, the distro block is gone.

Any recommendations for brand/model?

Ideally, I'd like to install the same valve you do so I can just use your setting.   :)

 

Also, does the old brake dash light connector need special treatment once the block is removed?

 

Also, are braided steel hoses for the flex lines an upgrade worth considering?

 

 

[cruiser54]

Do the braided lines also!!

I got my valve from Summit Racing. 

When the distro valve is removed, there are larger orifices for the fluid to flow through. 

 

 

[pizzaman09]

On 11/27/2022 at 8:08 PM, gogmorgo said:

If you’re bleeding out old murky brake fluid, you also know when you’ve hit new fluid. ;)

This is my approach!

I don't want to touch the brakes in my Comanche, they are nice and firm, stop with some pressure and work well.  I wish my shall be unnamed German sports car had brakes that felt as good as my Comanche.

[cruiser54]

On 11/30/2022 at 6:39 AM, gogmorgo said:

Huh. Don’t know why I thought that then. Weird. Sorry to put words in your mouth. It was definitely someone on here though 

Probably from me. I used the Gold and Blue Motul fluid alternately on my supercharged Miata during track days.