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Strange looking brake fluid???

AR67GTX

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I’m a bit embarrassed to say that I only in the last couple days, checked the brake fluid on this car I bought last year. They told me they flushed the brakes before the car was picked up for shipping and I found there were so many other things needing obvious attention, that I figured the brakes could wait awhile. Not smart.

Anyone seen this appearance in brake fluid before - I haven’t? Car hasn’t been driven for 4 or 5 days but brakes are good and strong (11” drums). Mixing DOT 3 or 4 mixed with 5? Whole bunch of water in the system? I suspect the car sat with little use for awhile.

369F3070-3841-4857-A2E6-627413477337.jpeg



No sign of leaking from the master or at least front wheel cylinders but I haven’t pulled the rear drums. The lines have been replaced and the hardware and shoes up front looked pretty recently rebuilt. I planned on buying several quarts of DOT 4 and flush the thing really good. Also ordered a replacement Raybestos MC to have on hand but holding off on the wheel cylinders right now. I may need to run some alcohol through it. But I’ve never looked in a master cylinder before and seen something like this.
 
Looks like an excessive amount of water for sure. Like you said, drain and flush until it is clean. Then check on it periodically.

I don't think it would look like that if regular fluid would have been added to dot 5. I'll try to experiment later today, I have both on hand.
 
I would get a brake flushing machine and do it that way.....and denatured alcohol is used by some people but imo it's not the best thing.
 
Are you speaking of a Motive bleeder type unit for pressure bleeding? I was going to install speed bleeders and just use the MC to pump fluid through but maybe it’s time to invest in a Motive unit
 
Are you speaking of a Motive bleeder type unit for pressure bleeding? I was going to install speed bleeders and just use the MC to pump fluid through but maybe it’s time to invest in a Motive unit
That looked pretty good but have never used one....and not sure if a local auto parts store would have one or something similar on loan. I would also remove the fluid in the cylinder and fill it with whatever you plan to use before doing anything.
 
Agree, suck the old fluid out of the MC before running it through the system when bleeding.
Turkey baster works well for that.
Probably wise to replace the rubber hoses while you're doing all that.
Then fill with fresh brake fluid & bleed.
Frankly, I'd be thinking about a dual MC upgrade, too.
 
Agree, suck the old fluid out of the MC before running it through the system when bleeding.
Turkey baster works well for that.
Probably wise to replace the rubber hoses while you're doing all that.
Then fill with fresh brake fluid & bleed.
Frankly, I'd be thinking about a dual MC upgrade, too.
This looks pretty bad and most likely needs a pressure flush....
 
Looks like just water I guess - with a good amount of rust. I sucked the fluid out with a Mightyvac, filled it and sucked it out again twice more, bushing the rust sediment loose with a small paint brush And then wiping the worst of the sludge out. The bubbles appearance just struck me as odd. I will still pressure flush out the lines and wheel cylinders.

The car sits in a well insulated, climate controlled garage so I think it was there long before I got it. I don’t think the dealer did any work on it.

87419EC1-D52F-4F31-B7F1-F896DACB87A0.jpeg
 
Mixing Dot 3 with Dot 5 it just wants to separate. If I stirred it, it would turn into a thin jell but soon after it would separate again.

Dot 3 and Dot 5 together.
20221030_135408.jpg


After stirring
20221030_151629.jpg


After sitting for awhile.
20221030_135718.jpg
 
Gotta say just one thing.... It's you brakes!!! If they fail you crash... Depending on the crash you or others may die...
Your already at a disadvantage with a single pot M/C
I recently got a car back on the road that had similar stuff living in the brake system...

New Master Cylinder....
New Wheel Cylinders...
New Brake Hoses...
Consider the condition of the steel lines
Flush everything...

The Motive bleeder is as good start but the lid thats supposed to seal to the top of the M/C doesn't, the lid itself is fine, the chains and bolts are junk...
My first attempt at using it I had more fluid on the inner fender than in the M/C.... I used 6" C clamps to secure the lid & it was allot better...
Since then I made a clamp from four short lengths of all thread and four steel bars that works perfectly...

At the absolute least pull the master cylinder & take it apart... Look in the bore, pitting? Hard residue? Think about how your gonna feel if/when the brakes don't work.... Wrong place to skimp....
 
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Gotta say just one thing.... It's you brakes!!! If they fail you crash... Depending on the crash you or others may die...
Your already at a disadvantage with a single pot M/C
I recently got a car back on the road that had similar stuff living in the brake system...

New Master Cylinder....
New Wheel Cylinders...
New Brake Hoses...
Consider the condition of the steel lines
Flush everything...

The Motive bleeder is as good start but the lid thats supposed to seal to the top of the M/C doesn't, the lid itself is fine, the chains and bolts are junk...
My first attempt at using it I had more fluid on the inner fender than in the M/C.... I used 6" C clamps to secure the lid & it was allot better...
Since then I made a clamp from four short lengths of all thread and four steel bars that works perfectly...
Was your Motive bleeder new or old?
 
Was your Motive bleeder new or old?
I bought it while I was in Texas getting my old car back on the road... I couldn't bleed thew brakes by myself & didn't have reliable help....

I have a 25+ Y/O Vacula bleeder at home, the Motive is better now that I've fixed it...
 
khryslerkid - thanks, I wish my fluid was that color. Pretty sure it’s moisture now.

I‘ve ordered a new Master Cylinder and will look at the old one and see what shape its in. For the price I’ll probably go ahead and put the new one on. I’m holding off on the wheel cylinders for now as they aren’t likely to cause a sudden, massive system fail. If during flushing I find sign of leakage or later, pull to one side I’ll dig deeper into them. Like I said above, the lines and brake pieces look pretty recent - although it’s probably due more to little use than having been done in the last couple of years.

I know most of the Corvette guys are using c-clamps on the Motive Bleeder. I’m not sure what the plate is made of but if it’s plastic I’ll probably put a small piece of plywood on top of it to stiffen it up and see if I need any bigger clamps.

Thanks for the comments.
 
khryslerkid - thanks, I wish my fluid was that color. Pretty sure it’s moisture now.

I‘ve ordered a new Master Cylinder and will look at the old one and see what shape its in. For the price I’ll probably go ahead and put the new one on. I’m holding off on the wheel cylinders for now as they aren’t likely to cause a sudden, massive system fail. If during flushing I find sign of leakage or later, pull to one side I’ll dig deeper into them. Like I said above, the lines and brake pieces look pretty recent - although it’s probably due more to little use than having been done in the last couple of years.

I know most of the Corvette guys are using c-clamps on the Motive Bleeder. I’m not sure what the plate is made of but if it’s plastic I’ll probably put a small piece of plywood on top of it to stiffen it up and see if I need any bigger clamps.

Thanks for the comments.

You can pull the boot back on the master cylinder and check for fluid. I would also check each wheel cylinder by doing the same. Water and rust can be quite damaging to these parts.
 
I'd still pull the drums and remove the wheel cylinders, pull them apart and clean the parts really well..with that much corrosion and moisture the walls of the cylinders might be in rough shape....maybe a quick hone to clean them up.
 
How would that much water get into a brake system? That's got to be more than just some condensation. Maybe someone made a mistake in the past? Years ago, I was working in a dealership parts dept. An old man came in and ordered all new rubber parts kits and hoses, etc. for his car. He had added fluid when he found the master cylinder was low. All his rubber parts swelled up and were ruined.... His mistake was accidentally using ATF instead of brake fluid. It can happen!
 
How would that much water get into a brake system? That's got to be more than just some condensation. Maybe someone made a mistake in the past? Years ago, I was working in a dealership parts dept. An old man came in and ordered all new rubber parts kits and hoses, etc. for his car. He had added fluid when he found the master cylinder was low. All his rubber parts swelled up and were ruined.... His mistake was accidentally using ATF instead of brake fluid. It can happen!

I seen the same thing with a company vehicle that the boss had someone different do the servicing. He used power steering fluid in the MC. The clear type and it was only used to top it up. One hour after the vehicle was put back in service, the driver called and said he lost his brakes. Very lucky no one was killed.
 
May be a winter project. I need to get finished with the new gears in my 67’s differential and get it back on the ground again.
 
Think original 66 MC cap are vented to air. The alcohol based brake fluid attracts moisture. As said wheel cylinders rebuild and or sleeved, brake lines flushed or replaced.
 
I’m not sure what the plate is made of but if it’s plastic I’ll probably put a small piece of plywood on top of it to stiffen it up and see if I need any bigger clamps.

Thanks for the comments.
The plate is cast aluminum....
 
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