Brake bleeding: pressure or vacuum?

Status
Not open for further replies.

par

Joined
Dec 5, 2002
Messages
157
Location
usa
Let's keep this strictly to brake bleeding.

If you were to buy one device to help bleed brakes, then would it be a pressure unit such as the Motiv, or a vacuum unit like the Mity-vac? Let's also assume cost is not an issue and base our decision on the merits of each method.
 
for a one person bleeding system I've always liked vacuum methods, they work prety well. I don't know much about the Motiv setup to be honest with you but any vacuum setups I've used are real simple and effective.
 
I'd use and recommend any pressure bleeder 1st over a vacuum bleeder.
I'm also a speedbleeder junkie.
 
I used Motive Bleeder on several cars, it is the easiest hand tool to bleed the brake, specially for Euro cars such as MB or BMW, no chance for air to get in the brake lines. I have Mityvac 7201 to change oil, transmission fluid; changing oil for newer MB is super easy with Mityvac.
 
With Motive Bleeder you don't worry about low brake fluid in reservoir if you have enough fluid in the bleeder tank. With vacuum tool, you need to watch the old fluid comming out of bleeder valve and also watch and top off fluid in the reservoir.
 
Read my comments in the thread "MityVac Evacuator -Bleed Brakes First Time" in this forum.
 
i use a mityvac, MATCO rebranded, shop air powered vacuum bleeder at work. works really well and will draw about 2 quarts in a minute. i dont have to worry about the master leaking down because i use an auto refiller. basically its a little tank you put on the master and it will drip brake fluid while the level drops.
 
This is one of those cases where it is good that there are different tools and techniques available.

There is no one best answer for all cars. By know the different methods available, alternatives can be used when the system doesn't respond to your normal method.

I like the vacuum method. It almost always works for me. With the right tool is is quick and painless. Sometimes with a stubborn system other methods need to be applied including the two person bleed, pressure, and gravity.

Which system works when all else seems to fail? Gravity.
 
I have a motive extractor and they give you a hose for brake bleeding with it. I have a new vehicle and am considering bleeding the system once a year as part of my annual routine. Do you guys bleed the furthest wheel first or last?
 
I've got both setups. I like the pressure bleeder better because I don't have to lug the hand vac setup to each brake. I just slip on a hose and turn the bleeder until I see the new fluid.

I alternate a blue fluid with an amber fluid so I can see when everything is purged (although that would obviously work for a vacuum method).

I have a Motive and a Mighty Vac. I use the might vac on the motorcycles but switched to speedbleeders on them.
 
HTSS_TR,

Originally Posted By: HTSS_TR
With vacuum tool, you need to watch the old fluid comming out of bleeder valve and also watch and top off fluid in the reservoir.



Actually there are several vacuum kits which allow you to hook a bottle with new fluid to reservoir so it does not get dry.
 
Hello bdcardinal,

Originally Posted By: bdcardinal


i use a mityvac, MATCO rebranded, shop air powered vacuum bleeder at work.



I am considering to buy vacuum bleed kit, however since I don't have compressor I need to choose it as well. Can you tell me if any cheap compressors which work from accumulator battery will do the job? Any hints on minimum pressure of the system are also welcomed ...

Thanks!
 
I use pressure, with the Motive, and am very pleased with it.

For me, the single most important factor over vacuum, is that I am somewhat OCD. The reason this matters, is many who use vacuum describe seeing small air bubbles in the brake fluid that is being sucked out. While the explanation, that this air comes from being sucked in around the bleeder screw, and does not matter to the effectiveness of the bleed job, this would just bother me.

My second reason, is I love the concept of not having to tote the main tank from one wheel to another. All I have to move is my wrench and the catch bottle.
 
If I pumped the Mityvac 7201 6-7 times then there was a lot of air being sucked into the Mityvac container, that didn't bother me at all knowing that air didn't get back into the brake system. After vacuuming the brake system the brake pedal was usually as firm or firmer than before.

What bother me the most was I had to remove the wheels to gain access to bleeder valves. Raising the car, placing jack stands, removing the wheels, re-installing the wheels, removing jack stands, lowering the car took too much work and time.
 
Vacuum bleeding (using mityvac or vacula) has been problematic for me - usually the pedal will be a bit softer after you're finished due to a small amount of air that is let in. I've noticed this on cars that come from other shops that also vacuum bleed.

The easiest way to resolve the issue, at least from my experience, is to allow each caliper or wheel-cyl to gravity bleed for a few minutes after the vacuum bleeding is performed.

However, even with the additional step, I've noticed that the pedal feel is different for the first 10-15 stops after the brake fluid service is completed. From what I can tell, the vacuum bleeding has some effect on the seals in the system.

I've never experienced any of these issues with a pressure bleed or the manual method.
 
Originally Posted By: BHopkins
I use pressure, with the Motive, and am very pleased with it.

[...]

My second reason, is I love the concept of not having to tote the main tank from one wheel to another. All I have to move is my wrench and the catch bottle.



Somehow this did not work well for me. I thought that I can simply connect the pressure bleeder, pump the pressure and forget about it. In reality however, I sucked compressed air into the system and was really amazed when observing it coming out from bleed nipple.

I saw many videos on youtube with Motive products and I saw an air pocket present in the hose which goes from Motive tank to reservoir. Somehow they this is normal, however noone provide an explanation that there is a 100% garantee this air will not go to MC.
 
Status
Not open for further replies.
Back
Top