Turkey baster for Brake Fluid????

[jdw1222]

I have a Jeep GC with 125K and the brake fluid is pretty dirty. What brake fluid is the best brand to use? Can I use the turkey baster method to change a little bit of fluid from the master cylinder from time to time to "freshen up" the fluid with out having to bleed the brakes or does this method allow air in the system. Would my best option be to bleed the entire sytem as opposed to the turkey baster method? Thanks for your help

 

[andyd]

turkey baster will only suction out the fluid in the reservoir . If you take it all , you will prolly get air into the system. It will take a long time and much fluid to do it this way. Brake fluid absorbs water starting from the moment the container seal is opened. Also Ive read somewhere that the highest concentration of water tends to be at the worst point to have it collect. right at the piston. I would bleed the brakes using the traditional 2 person method, or buy a check valve attachment that slips over the bleeder. My BMWs used nearly 2 qts of fluid to bleed until clear fluid was coming out the closest bleeder. The best brake fluid is the one with the highest boiling point. The label on the container lists this. Be careful when opening the bleeders, if they snap the caliper or wheel cylinder is junk. I give them a good shot of penetrating oil before trying them. If you arent familiar with the process read up on it.

 

[JDP]

I have never been able to remove enough brake fluid with the turkey baster to beable to get air into the system....What I would suggest is to remove as much of the old brake fluid as possible with the turkey baster and fill the reservoir with new fluid. Then bleed to remove the old fluid from the lines and calipers/wheel cylinders. saves bleeding time and leg effort for the "pumper"

JD

 

[DJ]

A turkey baster is useful to get much of the old fluid out of the MC before begining the regular 2 man bleeding. Brake systems do not curculate like other fluids so just topping off the MC with fresh fluid will not really do a good job of replacing fluid the way pan drops in a transmission can.

Also there is more to brake fluid than just the dry and wet boiling points yes all but the silicon trailer queen fluids are water absorbing but they do so at different rates and some of the fluids with the highest dry boiling points also soak up water the fastest. The boiling points are of little concern to the average driver anyway, by the time you managed to heat the fluid that much stockish pads would be useless anyway.
The Valvoline Synthetic brake fluid seems to have a good balance of all the good traits, just try to buy from somewhere that does a good volume of sales since brake fluids will absorb water through plastic bottles as it sits on a shelf. Metal cans don't have this problem but not a lot of fluids are sold in metal cans anymore. I know ATE is but it may be a little more hassle and expense than you want for this application, I hear German garages are a good place to find it.

 

[metroplex]

Silicone does not absorb water, but DOT 5 brake fluid does absorb/hold AIR which contains moisture and air by itself is also not as compressible.

So basically just stick with a DOT 3 fluid. DOT 4 seems to be much more hygroscopic than DOT 3.

 

[DJ]

I just mentioned silicon because it was all that stopped me from saying all brake fluids absorb water. The silicon fluids are meant really for show cars where you don't want a drip to damage paint, I have yet to see anyone really recommend using it in a daily driver.

 

[jdw1222]

thanks for the help guys! Exacly what I needed to Know!!

 

[VaderSS]

Valvoline's SynPower is the best easily available(get it at walmart, autozone...) It is not as hygroscopic as some fluids. ATE TYP 200 or Super Blue(same fluids, just different colors) are a bit better, but IMO, not worth the extra money or effort to find.

Saying Dot 3 absorbs less water than Dot4 is a gross generalization. I'm not even sure if it is correct. Ford's Dot 3 is about the most hygroscopic fuid out there...

DOT 5 does not absorb water, but if water get into the system, that water pools. Not a good thing. I do run Dot5 in my bike, and have for many years. It solved the problem I was having with sticking calipers. I would not run it in a car, and never in an ABS equipped vehicle.

 

[XS650]

Dot 5 has fallen a long ways from being the brake fluid to end all brake fluids when it was introduced in the late 1960s. At the time Dow touted it as the up and coming racing brake fluid, now it's a hanger queen fluid.

I used some when it first came out. It makes interesting stains in driveways. You can't se them when the concrete is dry, but they show up when it's wet. I had a couple of big DOT 5 spots in my San Jose driveway that were at least 25 years old that showed up every time it rained, then hid for the summer.