Comparing brake fluid flush methods

There's an old adage, opinions are like ********. Everyone has one. Seems like brake fluid flush methods are no different. Below are the different methods I know of. Maybe there are more?

• Vacuum extractor
• Pressure tank
• Buddy pedal pump
• Gravity
• Single man pedal pump

They all seem to have advantages, disadvantage and risks. But which is the best?

Either of pedal pump methods - Can damage the master cylinder from pushing seals into possibly corroded areas. Too risky for that reason alone.

Vacuum extractor - Hard to tell when air is removed due to bleeder screw leaks through threads. Risks inducing air to calipers. Fiddly process with catch container.

Pressure tank - This method seems like it might be the best but it has some risks. I have a "Motive" pressure bleeder and the last time I used it a hose sprung a leak and it sprayed brake fluid all over the engine compartment. Hard to tell how much brake fluid it has in it while using so the risk is it may run out of fluid. If that happens does it begin blowing in air? Also, with the tool attached to the master cylinder reservoir, I can't tell how much fluid the reservoir has because the old fluid discolored it the making it had to tell the level.

Gravity method - Way too slow. Might take all day to do four wheels.

 

Add Motive Bleeder without fluid in the tank. Have to take it off and check the master cylinder level but don’t have to clean it after.

I haven’t used it on Tacoma or 4Runner but worked well on other vehicles.

 

What's wrong with pumping the pedal?

since dawn of autos (my first, anyway) I attached a hose to the opened bleed valve, ran it into a mason jar, and pumped the pedal once or twice, filled the MB cylinder, and repeated. (Process was generally used for bleeding.)

But I live in a dry area, so maybe that's why I've never heard of internal corrosion of the MBC. External, sure.

To mitigate contacting corrosion, you don't have to push the pedal farther than you'd normally pump the brake, but now I'm more wondering how corrosion is not worse than a seal seeping. Both are bad, but if it starts leaking you'll have a chance to notice from the levels or leak, and it's only because it's corroded and maybe should be rebuilt anyway, right?

Personally I think this might be an over-worry. I've seen dirt and grime come out, but if you're seeing corrosion bad enough to damage the piston seals, you might even be able to feel it when you push the pedal.

But maybe I'm just ignorant to these dangers from living in low humidity areas, although I do get snow and road salt.

edit: Looks like motive makes lots of bleeding kits, but also makes a vacuum extractor. That's pretty cool.

 

Another option: Speedy Bleeders

 

I’m trying the gravity method next time. I have more patience since I’m older.

 

Interesting. I'm assuming you used it with a master cylinder reservoir specific cap. All I currently have is the universal cap that's secured with a chain. That would be a pain having keep removing and reattaching. Maybe I'll look into getting the tacoma specific cap.

 

What kind of BS analysis paralysis is this?

1. Suck out what you can from the reservoir with a turkey baster.
2. Refill to the full line with fresh fluid.
3. Hook up the DIY bleeder bottle to each wheel's bleeder nipple. Open the bleeder.
4. Pump the brakes until clean fluid comes out of the bleeder. For '09+ OR, turn the ignition key to "on", hold the pedal down and let the electric booster pump the fluid for you.
5. Close the bleeder.
6. Top up the reservoir.
7. Repeat at the other wheels.

For flushing, EricTheCarGuy recommends doing the wheels in reverse order to normal bleeding, i.e. do the wheel closest to the master cylinder first. Though it doesn't really matter that much.

 

I have only used the buddy pedal pump method once. Had no problem but that was on an older vehicle that had a lot less to go wrong. Actually, I have only read about people damaging their master cylinders. I guess the issue is the seals would be pushed onto an area that is never used, is not smooth and has a lip. Maybe the MBC should be rebuilt but I'd rather avoid that if I can. I have also heard of placing a block of wood under the pedal while pumping to limit travel.

The problem with the single person pedal pump method is air can be sucked into the calipers through the bleeder threads. Maybe applying a liberal amount of heavy grease to the threads might mitigate that risk.

 

Yes it was vehicle specific. I have 2 Toyotas so will either make or buy a specific one.

With 2 other brand of cars and brake fluid I’d rather than than have to clean it between each.

 

What kind of BS analysis paralysis is this? It got you to bite

Interesting point about the '09+ OR. We also have a 5th gen 4Runner OR. So that info may come in handy for that.

About the wheel sequence. Does it really matter with ABS since each wheel has it's own brake line?

 

You can just make your own instead, it’s also a lot cheaper:

 

Excellent idea! Thanks

 

Garden sprayer or something else supplying pressure?

 

It’s hooked up to the motive.

 

Take out the bleeder screw and apply teflon tape to the threads. Problem solved. Yes, there will be some leakage, but that is what rags are for.

 

Since I work alone I use a vacuum bleeder and don't touch the pedal at all.

Just keep topping up the master cylinder until I have run a good amount through the system and call it a day.

 

There’s a few videos that show just using a hand spray pump from something like a windex bottle attached to the correct size tubing then to the bleeder can make a one man job easier than getting up and pumping the pedal. You would still need to refill the reservoir after each wheel.
But the objective for many of us is to eliminate the wife or gf from our maintenance needs. We know how that goes.

 

I'm pretty much settled on a Motive bottle with a Speedi-bleed Toyota adapter. No external air (or anything else) required. You can also do it yourself...it's a 1-man/woman/mechanic job.

 

I used to it this way as well.

I have upgraded to Speed Bleeders - and am never going back to the old way.

 

I made my own pressure tank with a 1 gal garden sprayer. Drilled and tapped a small hole to insert a pressure gauge. Cut the sprayer tube and used nipples to adapt to commercial pressure bleeding cap - but you can easily diy a cap too.

Pressure gauge is to make sure it doesn't exceed 7 to 10 lbs, but 5 lbs is enough to force the fluid to flow quite well.