NO WONDER I HAD NO ABS AND TRACTION CONTROL!!!!!! (PICS!!!)

Okay, finally got around to installing the ebtcm (electronic brake traction control motor) I bought off the boards here.

Went to my Meineke (the one by my house is awesome!!), and had them install it. I'm no pro, and I don't want to mess with brake lines.....

They put it in and gave me the old one. Now, a little back story here. I got a replacement ebtcm here off the boards for a great price. Since I have an engineering degree I'm naturally curious as to how stuff works. So I took it apart and looked at the innards.... very complex but clean...put it back together and put it aside for another day to have it installed.

That day was this weekend, took it to Meineke and had them install it. They gave me back my old unit.

So I figured, "why not take this one apart and see its innards???...."

So I did

this is what i discovered!!!


The ebtcm is a motor on top of an ABS unit I believe. You have to remove some star bolts on the bottom and the motor detaches from the abs module. this also allows you to get into the abs module...this is what I saw. No evidence of brake fluid (which should be!!!) AND a crusty smelly residue on the internals


This is the inside of the bottom plate of the abs unit. Ideally, it SHOULD NOT be blackened like it is....and it smells like burnt hair!!!! I can only deduce that the fluid level dropped in here and something fried!!! It's very crusty and dry!


Another view, notice around the edge of each cylinder (what they are, I don't know) is a dry crusty flake of something. Does brake fluid crust?? I don't even know what this junk is!!!!

So, like I said, ebtcm smells like burnt hair, on the inside, it's full of crusty residue...so I can't imagine how it would done it....but it's NASTY!!!

The replacement unit I bought is much cleaner, no smoked residue or burnt our cyinders.

So, if your traction light is on, or your abs light is one...here's where to start looking. BTW, new, is $1100!!!!

Your right, no wonder it was not working.

Good job.

Bert

Wow, that's nasty gross inside!

To those of you reading this: this is why some folks recommend you change the brake fluid from time to time. Reason: brake fluid holds water. Lots of water.

But there's good news too, DOT 3 brake fluid is set up so that it turns dark when it's "wet"

SO if your brake fluid is dark, you really should get it changed before the trapped water in the fluid messes stuff up. As a rule of thumb, that'd be every couple years. For me, it's when the fluid is dark like light soy sauce. Which seems to be every couple years... Also, I use a DOT 3/4 synthetic fluid, but that's another story.

It would even be helpful to just drain the fluid from the reservoir and pour in fresh fluid if you don't have the time/$ right this minute to take it to a garage to be flushed.

The Riv's ABS, in order to replace all the fluid, requires a Tech II to run the ABS motor through a cleaning cycle. However if you use one of the air-charged pressure bleeders and you don't use more than 15 or so PSI pressure, following the directions you can change the fluid no problem. To find out more do a Google search, "How to change brake fluid." You will see articles like this:

http://www.trustmymechanic.com/brake_fluid_change.htm

If you look at "how to build a power bleeder" you will find articles like this:

http://p-car.com/diy/bleeder/

which is conceptually OK but the guy used the wrong kind of bottle. He thinks the pressure did it in but really I think the materials (nalgene) are incompatible with brake fluid and it is no surprise that it shattered. HOWEVER - a home garden sprayer would work fine as long as you don't pump the pressure so that the fluid aerates. If you search this Editboard you should find instructions I posted some time ago. I did not post pictures because I do not have a picture account anywhere. If you prefer to use shop air instead of a garden sprayer, you could probably use a radiator overflow bottle from the pick-and-pull - find one that has a flat bottom that you can make sit in the engine bay or on the ground. If you do it the way I did it, the bottle it needs to sit on the ground to siphon excess fluid back out as you finish the fluid replacement by releasing the pressure from the bottle.

Hope this helps

Albertj

The fluid coming out of the ebtcm was almost soy sauce black. however, I can't explain the crusty residue as just water...something fried.

But I must agree and stress to change your brake fluid every 2 to 3 years.... cheap PM will mean less $$ down the road!!

In theory you should change your brake fluid every 30k...

Looking again at the box, it appears brake fluid never actually surrounded those cylinders.... notice the metal around the cylinders isn't stained by the fluid (it's aluminum, the bottom plate steel)...

So how did they rust/fry???

Mysteries!!

Nate, thanks for sharing. I always wondered what it looked like in there!

Nate, they would have got rusty from water in the brake fluid. I am pretty sure that metal will not take on a stain from brake fluid.

There is a nice write up on brake fluids here:

http://forums.hybridz.org/showthread.php?t=103862

Background and highlights:

Brake fluid basically is ethylene glycols (similar to anti-freeze) and butyl esters. DOT-4 fluids have borate esters in addition to the butyl esters to increase the boiling point -- they ALSO will take on water faster than DOT-3 fluids will.

Water in an auto braking system comes in thru vents (each and every time you open the master cylinder for instance) and by vapor passing seals. This ingress of water can not be helped - so brake fluid is formulated to absorb water. Think of it this way - antifreeze (which by the way contains similar glycols) mixes with water. So does brake fluid.

Comment: I almost wonder if a previous owner was using DOT-5 silicone fluid in Nate's Riv. Water does not mix with it, the water would settle somewhere in the sysem and cause problems.

Albertj

That thing looks like the cylinder head off my motorcycle minus the cams

If that was bone dry I would think that crust has to be corrosion, like an engine block rusts when sitting around dry, just different metal, fluids, exposure, etc. That's pretty wild though. Definitely makes me want to go flush my brake fluid

I think something leaked in there, or moisture got in, but that cavity never was designed to hold flud from what I can see. Those are the bottom of the cylinders...

But some H20 got in there, enough to rust the heck out of the cylinders and the bottom steel plate!

My "new" unit works like a charm!!!!