Is it required?
If so how often?
Type/Brand of Fluid?

 

Required on a regular basis? No. Chances are by the time the fluid is crap, you've replaced the calipers maybe a few times thus dumping lots of new fluid in each time anyways. When you do it you'll need DOT 3 fluid, says so on the cap.

 

100% completely disagree with the above post. If you're waiting until you replace a caliper (which could literally be hundreds of thousands of miles), you're waaaay behind the power curve. Brake fluid is very hydroscopic, meaning it is suseptible to absorbing moisture. Moisture in brake fluid substantially reduces its performance by drastically reducing its boiling temperature among other things. Water just doesn't perform as good in the system as fresh fluid. I completely flush the entire system in all my vehicles every other year or with a brake job, whichever comes first. At a few bucks for an 8 oz bottle, it's a very cheap "bang-for-the-buck" upgrade. 4 bottles will completely flush my truck and leave a tiny bit for topping off. If you've never done it before and you've got age or mileage on your truck, then I guarantee you'll feel the differnce in the pedal.

 

Oh yea...Amsoil Series 500 DOT 3!

http://www.amsoil.com/a/Synthetic-Hydraulic-Oil

 

actually, brake fluid is Hygroscopic... but yes, it will absorb water if given the chance. For 90% of drivers a very little bit of moisture won't hurt anything.

American OEMs will say you "don't" need to flush your brake fluid. It is designed to last the life of the vehicle.

I would argue that regular flushing of the brake fluid is a waste of money and resources. If you are having trouble (soft pedal, etc) then doing a bleed with fresh fluid can help. But its not the fresh brake fluid that's helping as much as it is the action of pushing out any air that may have gotten into the brake system.

The other situations where you need to change your fluid regularly is if you tow a lot, live in the mountains, or drive your vehicle on a track. These are conditions that could lead to heavy brake use, thereby overheating and potentially boiling your brake fluid. A very serious issue.

But for most people that use trucks as a daily driver it is no big deal. As long as you keep your brake fluid cap on the reservoir you won't get enough moisture in the system to cause any problems.

Make sure you use a DOT3 brake fluid (any DOT3) and you will be OK.


PS... I design, test, and build master cylinders for a living. This is not just conjecture.

 

Bingo^, I was basically giving a normal driving, practical answer. I've only recently had to change calipers, at the 220k km and 240k km periods and with it came a fluid flush. Honestly, the pedal has always felt the same. The only time it was off was when there was a problem (caliper) or pads were low or warped rotor due to the aforementioned issues.

 

Good info, thanks

Rick

 

So add a quart of Dot3 and some 1/8" tubing to the list? Have a helper so I don't need a 1 man kit.
Any precautions other than not letting the master run dry?

 

When ahead and did the flush when I changed pads yesterday. Not very hard or time consuming once all the wheels are already off the truck, well worth the effort. The new brake fluid is CLEAR, the old was an amber color (did it start out as clear when new or is some fluid just amber?). For anybody else doing this use a turkey baster to remove the old fluid from the master cylinder (then put new in) before doing the flush. You will need 2 quart bottles (64 oz total), sounds like a lot but the master cylinder reservoir is bigger than it looks. Use 2 people, makes it a LOT easier, 5/16" tubing works well for the brake bleed screws to monitor the fluid color.

 

by "clear" I assume you mean a light yellow color? I have never seen a perfectly clear brake fluid before. New brake fluid varies from light yellow to darker yellow, depending on the brand.

Brake fluid will darken with age... it doesn't mean that it is bad. Some darkening is due to the heating of the brake fluid - it turns the additives a darker color.

 

Yes it was a light yellow, not clear like water. Compared to the old fluid it looked clear. The truck is 5yrs old and brake fluid is only $10. A lot cheaper than a caliper, master cylinder, or ABS unit. The old fluid may have been just fine, but I see it as cheap insurance.

 

I flush mine every 3 years.