Brake Flush: Motive Bleeder v.s. Mityvac MV7201

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I did the brake flush both ways on '00 MB E430 using Motive Brake Bleeder and Mityvac fluid extractor MV7201.

Last week I did the brake flush with Motive Brake Bleeder Kit 0251, installing the bleeder is easy for European cars. Following the instructions to the T, the rear brake fluid came out slowly not much faster than gravity bleeding. The front brake fluid came out much faster. Probably the rate of flow is so much different because rear brake lines are much longer than the front, therefore the pressure on the rear bleeder screws are much less than the front.

Today I decided to try re-flush the rear brake lines with Mityvac fluid extractor MV7201 (I don't use the Mityvac MVA7205 Brake Bleed Conversion Kit). Installation of the lines was very easy, took me less than 15 seconds. I then pumped the Mityvac 3-4 times to create a small vacuum, then I unscrewed the bleeder valve. As soon as I turned the bleeder valve by 1/8 turns brake fluid came out fairly fast, I turned the bleeder valve by 1/2 turns and pumped the Mityvac 6-7 times more. The brake fluid came out very fast at about 5-6 oz per minute. The passenger rear was done in less than 4 minutes and driver rear in less than 3 minutes. I had to keep top off the master cylinder every minute or so to be sure it did not run dry.

Comparing the two 1-person methods, clearly it is much easier to flush the brake system with a fluid extractor, specially with Asian and American cars and specially for the long rear brake lines. If you already have a fluid extractor to do oil/transmission fluid changes, just use it to flush the brake, no need to buy Motive Power Bleeder.
 
I disagree.

I can flush all four lines on my Saturn in under 8 minutes with the Motive Power Bleeder.

On the one occasion I used the vacuum method, the less than perfect seal at the bleeder screw resulted in air entering the system.

If you use more pressure with the Motive bleeder, the fluid will come out faster. I use about 20psi.
 
I've used both methods extensively, and I much prefer the Motive Bleeder, especially for European cars with their standardized cap. I never had a problem with low flow rates. Maybe there is something about the rear brake circuit on your vehicle which limits the fluid flow rates under pressure bleeding.
 
Originally Posted By: wgtoys
Maybe there is something about the rear brake circuit on your vehicle which limits the fluid flow rates under pressure bleeding.

+1

I think he needs to increase the pressure that he is using for the Motive. Also, he should consult his FSM to check and see if Mercedes has an automated bleed function that can be activated via scan tool.
 
Originally Posted By: The Critic

On the one occasion I used the vacuum method, the less than perfect seal at the bleeder screw resulted in air entering the system.


I used the plastic tube came with Motive Bleeder, it sealed the bleeder screw very well. The brake pedal was very firm after bleeding, so that there was no air in the brake system.

Originally Posted By: The Critic

If you use more pressure with the Motive bleeder, the fluid will come out faster. I use about 20psi.


I pumped the Motive Bleeder to maximum on the scale.

Originally Posted By: The Critic

Also, he should consult his FSM to check and see if Mercedes has an automated bleed function that can be activated via scan tool.


I check some of the MB Forums, my car doesn't have automated bleed function that can be activated via scan tool.

The Motive bleeder worked very well on '94 LS400 and Honda S2000. The only minor problem is install the bleeder cap to the master cylinder.

With the oil extractor, I can start bleeding the brake as soon as I remove the wheel, it took less than 30 seconds to hook up the bleed tube to the oil extractor.
 
Either should have worked.
Maybe the pressure needed to be raised.

I like vacuum for bleeds. It's just that the total deal is simpler for me.
 
Can I ask how do you use the MV7201 to extract brake fluid without the 7205 kit? What do you use to connect to the nipples and to the MV7201? Thanks
 
The Mityvac 7205 kit is not needed. I used the tube that came with the Motive Bleeder to connect to the Mityvac flexible hose then to MV7201. You can buy a foot or 2 feet of 3/8" flexible plastic tube from any hardware store to connect to bleeder screw and to Mityvac flexible hose.
 
no equipment needed to bleed/flush the Brembos on my car.

Gravity does a fine job.

Just open a bleeder and keep the master cylinder full.

No muss, no fuss, and no machines.
 
Tagging onto this old thread, I bought a Motive Power Bleeder a couple of years ago and flushed the brake fluid on a Honda Pilot. The Motive product is a great idea but I found the universal adapter would not provide a good seal. Consequently, I had a pretty bad leak at the fluid reservoir which made for a mess to clean up afterwards. I wish Motive had a specific adapter for the Honda reservoir.

I sold the Power Bleeder and have a Mityvac MV7201 coming. Hope that works better for brake bleeding, and in addition, I can use it to do the power steering fluid, engine oil, and tranny fluid.
 
I have had many problems with Vacuum bleeding, especially on ABS cars. That is why I plan on buying a Motive Pressure Bleeder.
 
I am glad to see a thread about this. I have been looking for a good "all-in-one" Mityvac-type of tool that I can use for all different fluids on my BMWs, i.e. Brake Fluid, Tranny Fluid, Diff Fluid, PS Fluid, maybe even coolant. I just want to be able to do these changes more quickly and more efficiently than gravity draining. Any suggestions? Thanks.
 
hmmm sure I necro'd an old thread, but just to say that there is more to the 1-man brake bleeding market than just these two (arguably) overpriced tools.

1. speedbleeder fittings
2. the Vacula
3. the HFT knockoff of a Vacula http://www.harborfreight.com/brake-fluid-bleeder-92924.html

I chose option 3 since I require a vacuum type to do trailer brakes (no pedal to push, and master cylinder is built into the tonque on surge brake systems) and it works great, esp for $25!
 
The pressure is regulated to be less [than the fronts] on the rear brakes of cars.
It has nothing to do with the length of the lines.
You were fighting a valve with pressure, and the vacuum method did not actuate it.
 
Originally Posted By: speedlever
Tagging onto this old thread, I bought a Motive Power Bleeder a couple of years ago and flushed the brake fluid on a Honda Pilot. The Motive product is a great idea but I found the universal adapter would not provide a good seal. Consequently, I had a pretty bad leak at the fluid reservoir which made for a mess to clean up afterwards. I wish Motive had a specific adapter for the Honda reservoir.

I sold the Power Bleeder and have a Mityvac MV7201 coming. Hope that works better for brake bleeding, and in addition, I can use it to do the power steering fluid, engine oil, and tranny fluid.


To update this post, The MV7201 with the MVA7205 kit works, but I get a lot of air leakage around the bleeder screw which slows the process.

Next up to try at my next OCI is my air compressor and Harbor Freight pneumatic brake bleeding kit. I still expect to get a lot of air leakage around the bleeder screw threads.

Overall, I prefer the Motive pressure bleeding method ... if I could have obtained a good seal at the fluid reservoir.
 
Vacuum bleeding can become a nightmare if the brakesystem
arent completly sealed and lets air in under vacuum...
The brake system arent built to hold vacuum wich is completly different to pressure if you look at seals.
 
Originally Posted By: ac_tc
Vacuum bleeding can become a nightmare if the brakesystem
arent completly sealed and lets air in under vacuum...
The brake system arent built to hold vacuum wich is completly different to pressure if you look at seals.


Very true, especially with older vehicles. I have had issues with vacuum bleeding for precisely this reason, but only on isolated older cars. Modern car = no problems...
 
I have a Motive Products Power Bleeder. I bought the kit a few years ago with the screw-on cap for use with Import cars (I now own three Saabs). I found the lack of a second swivel fitting in the hose to be a major problem so I bought their Black Label adapter which has a metal cap and a second swivel. Much easier to use than before with a single swivel!

I just ordered a plastic adapter cap tonight to bleed the brakes on my son's GrandAm. Since this cap is a 1/4 turn rather than a 5 or 6 turn cap the cheaper plastic version with single swivel should be fine.

This tool is great!
 
Originally Posted By: speedlever
Originally Posted By: speedlever
Tagging onto this old thread, I bought a Motive Power Bleeder a couple of years ago and flushed the brake fluid on a Honda Pilot. The Motive product is a great idea but I found the universal adapter would not provide a good seal. Consequently, I had a pretty bad leak at the fluid reservoir which made for a mess to clean up afterwards. I wish Motive had a specific adapter for the Honda reservoir.

I sold the Power Bleeder and have a Mityvac MV7201 coming. Hope that works better for brake bleeding, and in addition, I can use it to do the power steering fluid, engine oil, and tranny fluid.


To update this post, The MV7201 with the MVA7205 kit works, but I get a lot of air leakage around the bleeder screw which slows the process.

Next up to try at my next OCI is my air compressor and Harbor Freight pneumatic brake bleeding kit. I still expect to get a lot of air leakage around the bleeder screw threads.

Overall, I prefer the Motive pressure bleeding method ... if I could have obtained a good seal at the fluid reservoir.



2017 update: finding vacuum bleeding unsatisfactory for solo work due to excessive air leakage around the bleeder screw threads, I bought another Motive Power Bleeder and used it yesterday. It's a bit tricky getting a seal on a Honda. I had an airtight seal, but once I introduced brake fluid into the pressure vessel, I quickly sprung a leak. After futzing with the adapter, I finally achieved a good seal and was able to successfully bleed my brakes.

I think the trick here is to feel around the adapter cap and try to get it centered on the fluid reservoir before putting any pressure into the system. When I pulled off the cap after finishing the job, I found marks indicating it had not been centered at one point (probably the point where it leaked), and other marks indicating a more centered position (I assume where it didn't leak).

So next time (coming soon for another Honda due a BF change), I plan to feel around the cap and try to center it as best I can before putting it to work.
 
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