My Brake Flush Set Up

[RYDMOTO]

I have a A/C vacuum pump and got to thinkin one day and having been around WWTP labs, I came up with this set up.
The black hose is attached to the vacuum pump and the clear hose is pushed onto the brake bleeder.The long (brake line tube) tube keeps the oil from getting sucked into the vacuum pump. I start by removing the oil from the reservoir and the start at the rear right then rear left and so on. My first round I use ATE Blue and next round I use the amber color. What makes it easy is I can see when the amber turns to blue. If you want to have some fun, buy some red petroleum dye. I had asked a oil vendor for some red dye so I could chase down a hydraulic leak on a piece of equipment at work and he dropped off about a pint of dye. I can remember him saying "be careful with this stuff, there is enough here to dye a super tanker red". I use this for other oil related projects too.
Be forewarned the first time you use it to bleed brakes as you will see air bubbles when you loosen the bleeder valve. It's just air being sucked thru the loose bleeder valve.

 

[ctechbob]

Looks like you're starting a meth lab, but should work a treat!

 

[JohnnyG]

I don't think that metal tubing should go to the bottom of the container.

 

[RYDMOTO]

Looks like you're starting a meth lab, but should work a treat!

Real men snort oil dry.

 

[RYDMOTO]

I don't think that metal tubing should go to the bottom of the container.

You are right about that. It's never been a problem but as it fills up the air bubbles go thru the oil.
The purpose of the tube is so the oil does not get sucked into the vacuum pump. So yes I could trim 3
inches or so off the bottom of the tube. My vacuum pump has a oil level sight glass and I have never
had to drain any oil. But as I write this the oil vapor could contaminate the vacuum pump oil.

 

[John105]

Funny I got the Motive, with adapters for BMW and GM, and I built my own Toyota adapter.

Flash forward to today. I still use the Motive on the BMW.

But I now use this on the GM and Toyota

https://www.amazon.com/dp/B08PB4Q6VC?ref=ppx_pop_mob_ap_share

 

[RYDMOTO]

Funny I got the Motive, with adapters for BMW and GM, and I built my own Toyota adapter.

Flash forward to today. I still use the Motive on the BMW.

But I now use this on the GM and Toyota

https://www.amazon.com/dp/B08PB4Q6VC?ref=ppx_pop_mob_ap_share

I would NOT consider my set up explosion proof for fuel i.e. gasoline.
I like that you can see what is happening as you draw oil in or adding
oil with the motive.

When I bleed my brakes, it's a two handed operation. One hand holds the box end wrench on the oil
bleeder fitting and the other hold the tube tight to it.

 

[Donald]

Speed bleeders. My Motive brake bleeder is still in the box unused.

 

[RYDMOTO]

opinions vary

I will stick with my vacuum pump set up. It works fast and well.
I already had a vacuum pump and to by one for that purpose alone may not be
worth your expense. I do 5 cars when due.

What works for you is all that matters.

 

[The Critic]

I have never had consistent success with vacuum setups, at least pneumatic ones. I have found them to let air in at the bleeder screw and also aerate the fluid, to an extent.

I currently swear by pressure bleeding.

 

[Astro14]

I have never had consistent success with vacuum setups, at least pneumatic ones. I have found them to let air in at the bleeder screw and also aerate the fluid, to an extent.

I currently swear by pressure bleeding.

+1.

Exactly what i was going to say. Even when I tried wrapping the bleeders in Teflon tape, they still seemed to suck air.

 

[RYDMOTO]

+1.

Exactly what i was going to say. Even when I tried wrapping the bleeders in Teflon tape, they still seemed to suck air.

As long as the vacuum is present, you see some air being let "in" PAST the threads and no air is entering the caliper.
It's all physics. Keep in mind the vacuum pump is keeping a constant vacuum or suction.
I have no reason to change things up at this point. I only wrote this for those who already have a vacuum pump and might
want to use it this way. I use it to remove power steering fluid to do an oil flush. I do that three or four times to have a
relatively complete flush. Same with lawn mowers, instead of tipping the mower sideways to loosen the drain plug...
good enough for me.

At least we all are flushing our brake lines...right?
I can tell a difference when I flushed a car with 70k miles that had never been done. The oil was pretty dark.
And it might be true that some moisture does find it's way into the system causing a slight spongy feel on the brake pedal.

 

[Donald]

+1.

Exactly what i was going to say. Even when I tried wrapping the bleeders in Teflon tape, they still seemed to suck air.

What about switching to speed bleeders. Especially the SS ones. Then doing the vacuum bleed.

The SS bleeders could save a caliper replacement due to rusted on bleeder screws.

 

[Luftmasse]

I would say vacuum bleeding is mostly for speed. You gotta do the manual pump and hold method afterwards in order to remove the remaining air bubbles. It is a two step process.

BTW, Project Farm has demonstrated using an A/C vacuum pump with a mason jar. Seems to work well for those who don't have the luxury of having air compressor.

 

[Mav123]

I have never done the flush and know mostly computers, but not cars, is there a tool that helps? Like this? https://www.amazon.com/gp/product/B00GRV800S/

 

[Astro14]

As long as the vacuum is present, you see some air being let "in" PAST the threads and no air is entering the caliper.
It's all physics. Keep in mind the vacuum pump is keeping a constant vacuum or suction.
I have no reason to change things up at this point. I only wrote this for those who already have a vacuum pump and might
want to use it this way. I use it to remove power steering fluid to do an oil flush. I do that three or four times to have a
relatively complete flush. Same with lawn mowers, instead of tipping the mower sideways to loosen the drain plug...
good enough for me.

At least we all are flushing our brake lines...right?
I can tell a difference when I flushed a car with 70k miles that had never been done. The oil was pretty dark.
And it might be true that some moisture does find it's way into the system causing a slight spongy feel on the brake pedal.

I understand the mechanism by which that air is entrained.

The issue with vacuum set-up and entrained air, is that I can’t tell, clearly, when I am “done” bleeding.

E.G. new hoses. Are those bubbles I see the last bit of air coming out of the lines? Or just air that leaked in past the bleeder threads?

With a pressure bleeder, the bubbles stop coming, and the fluid changes to a nice, clear, bubble-free stream. I go a couple ounces further and call it good.