Turkey Baster Brake Fluid Change

[rslifkin]

After thinking about a brake fluid flush on the Jeep the other day, I poked through the service records, and realized that it likely still has the original brake fluid in it. IOW, almost 14 years old, and 14 years of untouched bleed screws. At that point, being that I'm planning to re-do most of the brake system with upgraded parts anyway in a year or so, I decided against taking the risk of breaking off the bleed screws in the calipers.

So, I figured I'd try the turkey baster change on the MC just for kicks. Yesterday, I drained the reservoir most of the way and then refilled, which left it with pretty clear fluid. I drove a bit more after that, and a good bit this morning. Today, I checked the reservoir, and the fluid was starting to look dark and gross again, so I changed it out. Pedal feels seems pretty much unchanged in normal driving, although it seems to be a bit better (firmer) under heavy braking.

I'm thinking that while obviously a full bleed is much better, the turkey baster change can definitely do something (being that brake fluid is hygroscopic, the new, dry fluid will draw some moisture up through the system and drop the total moisture content of the fluid in the system). Has anyone else tried this and had any good/bad results?

 

[user52165]

Yup, it works. Not as good as complete bleed and flush, but good.........much better than nothing. Kudos for your efforts.

Might do again for the PS reservoir......... with a cleaned out or another baster. Better buy a new one for your Thanksgiving dinner (LOL).

BTW - bleed screws need little more than finger tight. Maybe 5 - 7 ft/lbs. A flare (line) wrench is best.

 

[CivicFan]

At most it will change the brake fluid at the top end of the lines. Most of the fluid in the lines stays the same.

You could press the calipers with a C clamp in the same way as you would for a brake pad replacement to push the old fluid out of the calipers into the reservoir and then do the turkey baster method. That would get rid of more of the old fluid but not all.

 

[Loobed]

The turkey baster method works OK. You could also try the gravity method. Open the bleeder screw and let the fluid dribble out until you see clean fluid. This takes several hours for each wheel.

 

[mongo161]

I use this method often....between full flush of the brake lines. It keeps the fluid clear and you will notice a firm brake pedal.

Sometimes I question the fluids used by service shops when they bleed the system. How much of this fluid that they replace has been already exposed to air that they use as a replacement during the re-fill of the MC?

The reason being....it gets dark much faster after a brake bleeding at a service shop than any brake fluid that I use to refill, after the Turkey Baster method.

 

[The motor guy]

I've thought about doing this also. My question is do you have to worry about air getting in the the system or do you just syphon it out until it gets to the low mark to prevent this?

 

[Chris142]

All your replacing is the fluid in the reservoir. Your not replacing the important fluid in the calipers and wheel cylinders.

 

[user52165]

Originally Posted By: Chris142
All your replacing is the fluid in the reservoir. Your not replacing the important fluid in the calipers and wheel cylinders.


Are you sure? Why does the reservoir fluid darken in color after driving? The fluid migrates within the system.

 

[Shannow]

Yeah, but molecular diffusion will mean that over some time, all of the fluid will end up the same, so the stuff in the reservoir will pull moisture out of the lines, and new fluid will end up in the lines to equalise the nastiness.

 

[user52165]

Originally Posted By: Shannow
Yeah, but molecular diffusion will mean that over some time, all of the fluid will end up the same, so the stuff in the reservoir will pull moisture out of the lines, and new fluid will end up in the lines to equalise the nastiness.


Thank you. His even better term and explanation than mine: Molecular diffusion = migrate.

 

[Chris142]

Originally Posted By: user52165


Are you sure? Why does the reservoir fluid darken in color after driving? The fluid migrates within the system.
It doesn't pump in a circle like a PS system. It's open at the top and closed at the wheels so how is the fluid at the wheels going to get out unless you open the bleeders?

 

[user52165]

Originally Posted By: Chris142
Originally Posted By: user52165


Are you sure? Why does the reservoir fluid darken in color after driving? The fluid migrates within the system.
It doesn't pump in a circle like a PS system. It's open at the top and closed at the wheels so how is the fluid at the wheels going to get out unless you open the bleeders?


It doesn't get out. Did you see this post?

Yeah, but molecular diffusion will mean that over some time, all of the fluid will end up the same, so the stuff in the reservoir will pull moisture out of the lines, and new fluid will end up in the lines to equalise the nastiness.

 

[Donald]

I would attempt the bleeders. Put on PB Blaster for a few days on each screw. Get a 6 pt box end bleeder wrench (it has a odd offset) or a 6 pt socket if that will work and attempt each. Not to the point of breaking it. Try to tighten also as well as loosen. Need to break it free.

Do they even make 12 pt box end wrenches? So maybe I am being redundant.

 

[wings&wheels]

This is better than nothing but does not adequately flush the fluid at the wheel cylinders nor, possibly, at the abs pump. It will provide some benefit through diffusion, but how much is questionable.

The fluid in the reservoir will change color over time because it is exposed to the atmosphere via the vent holes in the cap but also because there is some circulation between the reservoir and the master cylinder. The tip valves that allow fluid from the reservoir to fill the m/c are open at rest and for a very small portion of the initial piston/pedal stroke when some fluid is forced back into the reservoir. Fluid will them move back into the cylinder when the pedal is released and the valves open when the piston is at rest at the rear of its travel. Watch the reservoir while someone presses the brake pedal and you'll see a little bit of movement. Some cars seem to do this more than others. On my TR6 it is a good little squirt...do not do this w/ the cover removed...trust me.

On most common systems, the fluid does not truly migrate through the lines to the m/c and back. On a disc system there will be a very little movement of fluid from the m/c to the calipers and back as you apply and release the brakes, but this is not circulation. There will be more movement back and forth on drum brakes where springs pull the shoes off the drums and compress the cylinders, but even this is not much.

A full flush requires getting clean brake fluid run through the entire system and even then, I am not sure that a home bleed using vacuum or a common pressure bleeder will get the fluid inside the abs pump..but that is another discussion.

w

 

[DaHen]

Use to do this technique often on the old Intrepid. However, am unable to get the turkey baster down into the brake fluid reservoir on the '06 Altima.
Seems that their is a baffle of some sort that is blocking me from getting down into the fluid.

Does anyone know how to get around this obstacle or get it out of the way?????

 

[OilProfessor]

The Professor recommends to "turkey baster" out the master cylinder resevoir, do a full bleed, and keep the resevoir topped off with fresh fluid. The Professor also recommends, to "turkey baster" the resevoir at every other, or every third OCI.

 

[aquariuscsm]

I do this as well with both brake and clutch masters. Fluid looks new :^)

 

[rslifkin]

I've done the power steering fluid this way a few times since getting the Jeep, and it's nice and clear, so that's not an issue.

As far as brake bleeding, I do plan to try the bleeders at some point (depending on when I'm going to do the whole upgrade). I just figured that doing it when I need to drive it back to Rochster in a week wasn't the best idea (in case I break anything), so I should see what the turkey baster would do.

 

[wrcsixeight]

Every time I have bled mine or my friend's brakes, the first pump or 2, or 3, the fluid was dark and nasty before turning clear.

I do not see how replacing just the fluid in the reservoir can do anything for the fluid a dozen feet away over a thin brake line, unless you are just about to bleed the system.

Do spray the bleeders with PB blaster or similar before you return home. Then hit them with a detail wire brush and more PB blaster for a day or 2 before putting on a wrench on them grabbing the flats as low as possible.

On a somewhat related note,


My upper ball joints are threaded in and I heard horror stories that even the correct BJ socket and an 8 foot breaker bar were unable to unscrew them in the control arm. Several times before I got the new parts I PB blasted the ball joint/ control arm seam, wire brushed it scraped away all corrosion with a dental pick and more PB blaster, repeat.

When the time came to unscrew the ball joints, I put about 60% of my strength on a 3 foot breaker bar before falling backward off the stool. They came out so easy and the receptacle was shiny and wet when I got them all the way out.

Give the penetrant time to work, and make it easy for it to get where it needs to be, and save yourself some pain.

I pretty much refuse to try to unscrew anything on my 22 year old vehicle without first prepping it for the PB blaster and giving it plenty of time to work.

 

[TooManyWheels]

Originally Posted By: OilProfessor
The Professor recommends to "turkey baster" out the master cylinder resevoir, do a full bleed, and keep the resevoir topped off with fresh fluid. The Professor also recommends, to "turkey baster" the resevoir at every other, or every third OCI.


Does the professor always speak in the third person? If so, he should stop...