Positive pressure device or vacuum device for brake work?

bluejeep

bluejeep

TJ Enthusiast
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What's better for bleeding brakes after replacing parts - positive pressure or vacuum? Looking for a DIY 1 person device

I recently replaced front calipers/pads/rotors (installed black magic kit) including extended lines, also replaced right rear line.

Until I found/created a leak in the right rear line I had the front bleed and seemingly working with good pedal pressure.

Suddenly I had no pedal pressure and found a leak in the right rear line being the cause.

Now that's replaced but getting no pedal pressure, I believe it's from a thing in the system that blocks fluid from going into the 'leaking' system.

So I either need to push fluid into the system (specifically the right rear) or pull it.

Any advise on which method to use

tia
dave
 
I just finished this (relatively) same process.
Used both Motive pressure, and also manual and power vacuum bleeder.
Pressure was faster to set up than the power vacuum, and faster overall than either vacuum.
 
bluejeep said:
What's better for bleeding brakes after replacing parts - positive pressure or vacuum? Looking for a DIY 1 person device

I recently replaced front calipers/pads/rotors (installed black magic kit) including extended lines, also replaced right rear line.

Until I found/created a leak in the right rear line I had the front bleed and seemingly working with good pedal pressure.

Suddenly I had no pedal pressure and found a leak in the right rear line being the cause.

Now that's replaced but getting no pedal pressure, I believe it's from a thing in the system that blocks fluid from going into the 'leaking' system.

So I either need to push fluid into the system (specifically the right rear) or pull it.

Any advise on which method to use

tia
dave
Click to expand...
Manual bleed with the key on, parking brake off to watch the dash light for the brakes. Either that or reset it and use a lock out on the shuttle valve by removing the switch and replaced it with a fixed non spring loaded plunger.
 
Pressure is easier, but I prefer vaccuum because if something should leak it isn't pushing brake fluid all over the place.
And when all done I still get a buddy to pump and hold the old fashioned way just to be positive there are no air bubbles. Probably a waste of time (and a buddy), but I'm anal about brakes and steering.
 
Goatman said:
Pressure is easier, but I prefer vaccuum because if something should leak it isn't pushing brake fluid all over the place.
And when all done I still get a buddy to pump and hold the old fashioned way just to be positive there are no air bubbles. Probably a waste of time (and a buddy), but I'm anal about brakes and steering.
Click to expand...
If you were anal, you would not do the pump and hold.
 
Goatman said:
Pump and hold has worked since I was in school.
Click to expand...
Someone who is anal would know that the pump and hold method entrains small air bubbles in the brake fluid that later settle out in a larger bubble in the caliper. If you do the pump and hold method on a TJ, go back the next day with a clear hose on each bleeder and you will get air out every single time. Simply stroking the master during a manual bleed via the single push to the floor and hold with the bleeder open will do the same but to a much lesser extent. We still go around and hit the corners with a 1 pump bleed the day after and always get a small bubble out.

Pay closer attention to the fluid in the clear tube, you will see the tiny bubbles that do not ever quit.
 
If bleeding goes nominally will the brake light come on each time the pedal goes to the floor? Needing a pedal pump to reset light/shuttle valve before bleeding again.
 
I like to use the free vacuum bleeder rental tool from the auto parts stores. They work great.

My tip is to use teflon tape to seal the bleeder screw to the caliper when you are bleeding. Then after done bleeding, I pull the bleeder screw off, remove the tape, and reinstall/tighten.

I thought about getting a motive power bleeder but what’s the point? More money and more mess to clean/store.

And why mess around with doing the brake pedal method when the bleeder tool rental is FREE!
 
Vtx531 said:
I like to use the free vacuum bleeder rental tool from the auto parts stores. They work great.

My tip is to use teflon tape to seal the bleeder screw to the caliper when you are bleeding. Then after done bleeding, I pull the bleeder screw off, remove the tape, and reinstall/tighten.

I thought about getting a motive power bleeder but what’s the point? More money and more mess to clean/store.

And why mess around with doing the brake pedal method when the bleeder tool rental is FREE!
Click to expand...
I dont put brake fluid in my motive. I also installed an air line quick coupler on the hose to the reservoir so i can disconnect the cap at the master without loosing the pressure in the bottle. It also makes it easy to switch between the few master cap adaptors i have for other vehicles.
 
No hoses....place pig mat on runway of lift or floor if using 2 post or jack....

Gravity bleed...
Once gravity is dripping fluid...
Get partner to push...
Push pedal in once (holding)....
Partner says down....
Open valve.....
Partner says floor....
Close valve whilst the partner holding pedal...
Say (out) to partner...
Partner let's off pedal....

If air still at wheel...repeat until no more air....

Some things to note...
If the brake system has had a leaking line odds are you'll have to bleed the master cylinder first. Every pedal release while driving is sucking air into the system.

Pending on how filthy the inside of MC is...now might be a good time for that new one.

We professionally make lines all the time here. Sometimes just sections and sometimes a whole system for the entire motor car.

S.U.R.&R. Company is absolutely the best in the business.
Brake, fuel, A/C, Tranny ...
Fittings for everything and tools for such the job.
This is the greatest flaring tool ever made especially for on the vehicle use.
👇👇👇👇👇👇👇
20210115_184606.jpg
 
Lou said:
I dont put brake fluid in my motive. I also installed an air line quick coupler on the hose to the reservoir so i can disconnect the cap at the master without loosing the pressure in the bottle. It also makes it easy to switch between the few master cap adaptors i have for other vehicles.
Click to expand...
My plan was to do this but then decided it would be a pain to add fluid many times because the reservoir is not that big. BTW I hate spelling reservoir and spell check/auto correct rarely get it right.
 
I use the manual procedure as Blaine recommends. It essential similar to what Rubicon88 detailed, adding only that I let the pedal up slow and never pump in an effort not to aerate the fluid. Simple and works best. And with manual bleeding you can visually monitor the amount of air coming out easier because the fluid is moving slower.
In the past I used a second reservoir cap that I drilled and fitted a male air hose fitting. I fill it and pressurize >15-20psi and bleed the wheel cylinders farthest first. Cheap version of the pressure bleeder if you swing that way.
 
Juggernaut said:
I use the manual procedure as Blaine recommends. It essential similar to what Rubicon88 detailed, adding only that I let the pedal up slow and never pump in an effort not to aerate the fluid. Simple and works best. And with manual bleeding you can visually monitor the amount of air coming out easier because the fluid is moving slower.
In the past I used a second reservoir cap that I drilled and fitted a male air hose fitting. I fill it and pressurize >15-20psi and bleed the wheel cylinders farthest first. Cheap version of the pressure bleeder if you swing that way.
Click to expand...
When i worked in a shop this is what i did. I bought the motive for side jobs where i might be in someones driveway without an air compressor.
 
I broke down and bought a Motive, the type with the built in pump.

Works very well, and easier than the old pump and hold method. Cleans up easily with some isopropyl alcohol.

Also, oddly enough, the master cylinder caps are the same on my Jeep, and Dodge Ram diesel, and New Holland bale wagon!
 
Modoc Guy said:
I broke down and bought a Motive, the type with the built in pump.

Works very well, and easier than the old pump and hold method. Cleans up easily with some isopropyl alcohol.

Also, oddly enough, the master cylinder caps are the same on my Jeep, and Dodge Ram diesel, and New Holland bale wagon!
Click to expand...
I found the Motive very very easy to use but a pain to clean as I dont do this for a living, just to maintain a few vehicles.
 
I picked up a cheap vac kit at HF, it's a MultiVac, works just fine. Watch out breathing the fumes from denatured alcohol, it'll fuck you up! Just a warning for those who haven't used it before.
 
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