Do I remove and keep the calipers upside-down when replacing brake fluid. (2 Viewers)

[Antipodes4WD]

I have no record of the brake fluid ever changed, so it was the time. After watching countless Youtube videos I settled on the vacuum pump method. Strangely enough, only a single line goes to the rear axle and another to front brakes. I always thought ABS works on individual wheels...

The available videos are either a disassembly, or just adding liquid to the master cylinder and sucking from bleeding screws.What worries me is that (especially at the front calipers) the bleeding screws are at the top. I see no way the old fluid will leave the caliper's cylinders to be replaced with the new fluid. Likely the fluid in those cylinders is as old as the car. Even if I hold the caliper with the bleeding screw down I am not sure it will help. The proper job would be disassembling the line and draining the caliper.

Am I missing something?

 

[excessive]

its very simple to bleed the 100 series brake system. just open the bleeder, have someone pump the brakes, and then close the bleeder while the pedal is being held down. repeat a few times at each wheel and you're good to go. dont over think it

 

[Trunk Monkey]

He's talking about fluid replacement, not just bleeding. There's several threads on people's best methods, simplest is to use something to get as much fluid out of the MC as you can (turkey baster, etc.), then add new fluid, then start bleeding each corner, bleeding until you see new clean fluid coming out. Doesn't get 100% new fluid, but way better.

 

[Devils Paw 80]

Or you could use a brake fluid tester pen to check water content of the fluid. If it's not above acceptable level and fluid isn't dirty then the job could be skipped.

 

[Antipodes4WD]

He's talking about fluid replacement, not just bleeding. There's several threads on people's best methods, simplest is to use something to get as much fluid out of the MC as you can (turkey baster, etc.), then add new fluid, then start bleeding each corner, bleeding until you see new clean fluid coming out. Doesn't get 100% new fluid, but way better.

Yeah, I think that comes to the definition of the 'replace brake fluid' in the attached doc from Toyota. What is seen on the Youtube is mixing old and new break fluid (and if I flush a gallon through the system mostly new) down the pipes and calling it done.

If I read the ellery.com.au manual (a physical book), they also have a 'Brake fluid replacement' chapter page 261. They go into trouble of bleeding dry the master cylinder, holding calipers upside-down, removing cylinders.. etc.

If I have to follow Toyota schedule of every 24 months 'replacement' and do it as the workshop manual suggests, perhaps I start looking for an electric vehicle option... But as the mainstream Youtube goes it is clearly a half-arsed job.

Some suggest that 'In Toyota we trust' and the caliper chambers are designed to be flushed in the process, but I have serious doubts about that.

 

[RapidRob]

Your logic is sound if you want absolute 100% clearance of all fluid.
However, the reason for the bleeder being on top is so that the air will come out of the system. If you drain the fluid upside down be sure to also
bleed them again after reinstalling them right side up. If you bleed them thoroughly (maybe twice) without going to the trouble to remove and flip them you will get the vast majority of the old fluid out. Just do it again (just a quick caliper bleed) after driving a little if it makes you feel better.
100% air removal is much more important than 100% fluid exchange. My 2 cents. ($US!)

 

[Antipodes4WD]

Your logic is sound if you want absolute 100% clearance of all fluid.
However, the reason for the bleeder being on top is so that the air will come out of the system. If you drain the fluid upside down be sure to also
bleed them again after reinstalling them right side up. If you bleed them thoroughly (maybe twice) without going to the trouble to remove and flip them you will get the vast majority of the old fluid out. Just do it again (just a quick caliper bleed) after driving a little if it makes you feel better.
100% air removal is much more important than 100% fluid exchange. My 2 cents. ($US!)

With tightening the bleeder before the vacuum is disconnected all went well. As long as the old liquid does not badly affect slave cylinders I am content with the idea that the name of the game is just to remove the water from the bulk of the liquid. Hopefully the water left in the slave cylinders will redistribute eventually. The old liquid looked exactly as the new one, not what they branish in front of the camera on Youtube. With my style of driving and manual gearbox I am not expected to overheat the liquid anyway.

I am also wondering would it do any damage if I add a few milligrams of plumbers dye so that the next time I will see when the new liquid is coming out?

 

[2001LC]

We either:
Ignore old fluid remaining in calipers. Which is just one more reason to flush often, which skim some out of caliper.
Or we compress pistons. By expanding outward the brake pads pressing in pistons, with bleeder open.
Or rebuild the caliper.

Personally I only use Toyota brake fluid and flush every 2 to 3 years. When replacing brake pads, is also excellent time to flush.

 

[OEMGUY0720]

The brake fluid reservoir of my 2006 is designed like a drain pan, the outlet is raised so I cannot fully drain the old fluid either by gravity or positive pressure. Is this the same with YM 98-2005? I haven’t fully inspected those years and do an actual comparison.

 

[hoser]

All of the electric boosters have the same reservoir. It's a bunch of compartments of varying height. The outlets are all along the bottom. I didn't take it apart fully. Too much flying hot plastic. You would have to remove the reservoir and rotate it round and round, side to side to get all the fluid out.

 

[Antipodes4WD]

We either:
Ignore old fluid remaining in calipers. Which is just one more reason to flush often, which skim some out of caliper.
Or we compress pistons. By expanding outward the brake pads pressing in pistons, with bleeder open.
Or rebuild the caliper.

Personally I only use Toyota brake fluid and flush every 2 to 3 years. When replacing brake pads, is also excellent time to flush.

Is there a technique to compress pistons while mounted, or there is a tool to compress when the caliper is removed?

 

[2001LC]

I've these, they're a bit thin and will bend if using tips, but get in tight spacers.

These look stronger, but a bit thick.