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I assume a great number of you already know all about this already, but there's a few of us who are 'closet mechanics' just coming out of the closet on the weekends to 'wrench our Pantera' and I learn from a Master Mechanic in the family.

There's DOT-3 brake fluid, which is what my Pantera calls for. There's DOT-4 brake fluid, which is what just went into it. Then there's DOT-5 brake fluid, which is full synthetic, and not compatable with systems which used DOT-3 before.

DOT-4 is best for a non-racing Pantera because it has the following advantage. In 20 years it will still be good-to-go (and stop). DOT-3 will deteriorate, beakdown and absorb moisture in the same 20 years. This can cause problems like pitting in the insides of the brake and clutch system. DOT-5, besides being non-compatable with DOT-3 will solidiy into partial solid silicone after 20 years. DOT-4 is more expensive than DOT-3, but what's cheap is cheap, and my Pantera ain't cheap, so I sprang for the $40 to $50 per gallon for a galon of DOT-4.

A Gallon? That's what I asked. We actually used closer to three fourths of a gallon of DOT-4.

We all know the hydraulic fluid needs to be changed unless we remember doing it in the last 10 to 15 years. Mike-the-Mechanic brought home this Brake Bleeder tool he told me about. Hey, I bled brakes in high school. Just get some one to step on the brake pedal while I loosen the screw. What could this gizmo do? Keep spillage from happening? Spillage is not a good thing, I agree, it eats paint off the front fender or anywhere else, but buy a tool? This brake bleeding tool not only makes it a one man job, but calculate how many pumps with the brake pedal it will take to get 3/4 of a gallon of hydraulic fuid in there. So this tool has a place to attach your air compressor hose to it, a half gallon plastic container and a four foot clear plastic line with a little rubber female fitting on the end that fits the bleed valves.

Ready, set, go. Up on jack stands, wheels off (not required, but much easier). Off with the master cylinder caps, both clutch and brakes. Fluid looks cloudy and even milky in the front portion of the brake master cylinder. This front part services the back brakes. That turned out to be contaminated with moisture. But there were no leaks in the hoses going from the chassis to the suspended calipers. Inspecting the back part of the brake master cylinder, its a little cloudy, but not milky. At the bottom of the reservoir is black looking suspended matter. This is what all cars look like after a few years. The black sediment is not cause for alarm. The clutch master fluid was really black and not at all transparent.

So if you don't have a compressor nd a fancy brake bleeding tool, I suggest you get one of those big syringes that they give horses shots with or they use in chemistry lab or the dentist gives you to flush out your gums after oral surgery. Cover the area around the master cylinder with a big towle so it doesn't ruin paint or carpet. You are going to spill some of this DOT-4. With the suction from one of these devices, drain most of the master cylinder. (Do one part of the front master at a time. Then do the clutch seperately.) Do not drain it down to the holes or you're going to have test later for air bubbles. Pour the DOT-4 in a water glass and get a screwdriver out. I use the screwdriver to make the DOT-4 go down the hole by placing the tip of the screwdriver in the reservoir and placing the blade of the screwdriver on the lip of the glass. When pouring, the fluid follows the screwdriver, spilling less, but still dribbling down the glass onto the towel.

Do this several times, fill up the reservoir, stirr it around to get that black stuff back in solution. Then suction out the reservoir. Next fill up the resevoir again and either turn on your handy little compressed air bleeder and fit it to each of the caliper bleeder screws or get your friend to start pumping the brakes, with the old style of bleeding. Pump it up, loosen the bleeder screw, let the fluid out, and tighten. Repeat, repeat, repeat. Hey, Mike-the-Mechanic had the right tool, so I just kept letting the fluid level go down to almost empty, refill while the bleeder keeps sucking, and then going all around the car like that. As I said, the front part of the Brake Master was for the rear brakes, so that's the reservoir to keep filling when bleeding the rear brake calipers. I kept stirring the fluid in the part of the master
cylinder as it was being depleted out so it would be really clean and without black stuff. I kept using the screwdriver as a dipstick, so I knew how close to the bottom it was getting. Let the reservoir go down to about 3/8" of fluid before the bottom, then fill 'er up again. After about 10 reservoir tank fulls, the fluid gets pretty clear. That's the way I want it, I don't plan on doing it again for another 10 to 15 years.

The clutch master cylinder fluid was particullary dirty. Black. The sides of the clutch master were coated black. This is also a new clutch master cylinder, so I was surprised how black the walls were inside the clutch master cylinder. This little cylinder got about 10 to 15 refills of DOT-4 while the suction bleeder tool kept taking down the reservoir every 3 to 5 minutes. I kept stirring the fluid in the reservoir, and now it is as clear as Budweiser or Coors. About the same color too.

Test drive. It feels a little easier to apply the brakes or disengage the clutch, but solid. Both the brakes and the clutch had to pump up a while to get the pedals back up exactly where they were.

Keep in mind that disk brakes do not have adjustments like drum brakes do. So that means when your brakes a wearing down a little, like the brake pads are getting a little thinner, that means you need to top off the brake master cylinder. The hydraulic fluid will go down in the master cylinder and be filling more of the piston chambers in the brake calipers.

Check for any leaks on the rubber hoses between the wheel and the chassis. It should be apparent. Look for fluid, greasiness or dirt/dust collection on the hoses.

I took my Pantera to Mike-the-Mechanic's house, so it had time to warm up some. While there and up on jack stands I slid around under it and found a drop of green fluid under the car. So I traced it back to the radiator connecting hose, just needed to tighten the clamps is all. I just got it about 5 months ago, so it was nice to see silicone hoses. Thank my lucky stars the doctor who owned it before me tok good care of it. A hose clamp tightening here, a gallon of fluid there, get Mike to lean out the carb a little to try and dial it in....

Closet mechanic (me) finds Master Mechanic Mentor (Mike, my brother-in-law). Lucky stars, celestial alignment, oops, that reminds me, Mike pointed out I need an alignment for the new A-arm bushing project. Getting a little feathering on those front tires. Gotta take her to the shop for that project.

Scatch a project off the checklist, add another project to the checklist. On and on, but its worth it, even when it sucks, it's still worth it later.
Original Post
I think you've got a couple of incorrect assertions.

In 20 years, a DOT-4 fluid will be just as full of moisture as a DOT-3 fluid. The real difference between DOT-3 and DOT-4 brake fluid is the wet and dry boiling points (DOT-4 is higher) not improved moisture absorption. Many DOT-4 fluids tend to absorb water even faster than DOT-3 fluids and must be change more frequently. DOT-5 does have higher temp ratings but is silicon based rather than 'synthetic'. DOT-5 fluids do not absorb moisture. But since water can't be absorbed into the silicon fluid, it collects in within the brake system in puddles where it tends form rust spots.

The only way to remove the accumulated moisture from your brake system is to flush the fluid and replace it with new fluid from a sealed container (with no moisture). Safety specs for track events usually require a complete fluid flush within the previous 6 months to make sure that moisture content is mimimal. Not only does flushing the brake fluid help keep your system more resistant to brake fade, it also removes the water that corrodes the internal metal components. More often is definitely better in this case.

Dave Bell
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