Another brake bleeding question

[dan88911]

When bleeding brakes with the Motiv pressurer bleeder is it necessary to manually bleed in conjunction?

I have been reading some post that state it is not.
However, Bentley's states with pressurer bleeding; Have a helper hold brake pedal down. Open bleeder screw. Have helper pump brakes at least 12 times with bleeder screw open, holding pedal down on last pump. Close bleeder screw and release brake pedal.
Thanks for any shared insight.

[Oh Haha]

If the Motiv bleeder is used properly, you shouldn't HAVE to manual bleed.

[Justin@Athens]

I don't think its required, but if the car has ABS or if you just want to get the old fluid out of the master cylinder--then it won't hurt anything.

[michael lang]

No you should be pretty much good to go, that why it is called one man brake bleeding. Every now and again I will get the wife to sit in the seat and the brake pedal for me but I know it really is not needed.

[tvanbroekhoven]

I've tried the motive thing, but had to conclude that the 2 person method worked best. YMMV

[na2ub]

The motive bleeder works well for routine bleeding. However, if you get air in your lines, like replacing a brake hose or removing a caliper, the 2 man pedal bleeding helps get the air out, because it creates a lot of pressure in the system, which helps dislodge / blast the air bubbles out through the bleeder. After rebuilding my calipers, I could not get all the air out with my pressure bleeder. I did the best I could, then drove it with 75% pedal pressure. Over time, the air will naturally move down the lines. My pedal pressure firmed up to maybe 85% now, and I will pressure bleed them again to get that last 15%, now that the air has had a chance to "naturally" bleed itself.

[Bob Kontak]

Originally Posted by na2ub

My pedal pressure firmed up to maybe 85% now, and I will pressure bleed them again to get that last 15%, now that the air has had a chance to "naturally" bleed itself.

I have found this procedure to be the most effective on cars where I open up the brake system.

Drove my 911 for 12 years before reading the suggestion to do it twice and it makes a real difference.

FWIW - I actually like the "old" pedal feel better as the pedal has a little more travel. When completely purged of air it feels like stepping on a brick. Car stops fine, just feels different.

[mnez]

I have used the Motive bleeder for a long time with no problems. Have never found the need to manual bleed since. Just be sure to clamp off the vent tube. A second bleed after driving for a while has often turned up an extra bubble. I never put fluid in the motive (as their instructions suggest), just use it to pressurize the reservoir.

After recently letting all of the fluid out of the lines for a front caliper rebuild, I had good success with this low tech method: Filled the reservoir, opened the right bleeder (with a clear hose attached) and waited for gravity to bring the fluid down to the caliper and out of the hose. Closed the bleeder and repeated on the left front. Then bled the right and left with the Motive, putting one reservoir's worth through each front wheel. Most of the air had come out with the gravity bleed. Then bled the rear. I didn't touch the brake pedal anytime during the re and re procedure. I second bleed in a week did not turn out any new air, and the pedal is rock solid.

It didn't take long for the gravity to move the fluid down, less than 5 minutes.

[Neel]

With the Motive bleeder, used properly, you should not have to manually bleed your brakes.. Personally, I use a MityVac 04000 with no problems.. If replacing a master cylinder, I always bench bleed it before installing..
There's probably as many bleeding procedure opinions as there are Pelicans, kinda like the engine oil threads, transaxle oil threads and the A/C threads..

[RSTarga]

Just the Motiv with no fluid in the Motiv. I recently changed all 4 brake lines and had no bubbles and a very firm pedal. No pumping! worth every penny.

[911pcars]

Originally Posted by mnez

I have used the Motive bleeder for a long time with no problems. Have never found the need to manual bleed since. Just be sure to clamp off the vent tube. A second bleed after driving for a while has often turned up an extra bubble. I never put fluid in the motive (as their instructions suggest), just use it to pressurize the reservoir.

After recently letting all of the fluid out of the lines for a front caliper rebuild, I had good success with this low tech method: Filled the reservoir, opened the right bleeder (with a clear hose attached) and waited for gravity to bring the fluid down to the caliper and out of the hose. Closed the bleeder and repeated on the left front. Then bled the right and left with the Motive, putting one reservoir's worth through each front wheel. Most of the air had come out with the gravity bleed. Then bled the rear. I didn't touch the brake pedal anytime during the re and re procedure. I second bleed in a week did not turn out any new air, and the pedal is rock solid.

It didn't take long for the gravity to move the fluid down, less than 5 minutes.

+1
Bleeding with a pressurized tank seems to do the job for many, but there also seems to be many owners who don't find it very effective (besides circulating many quarts of HD fluid into the trash).

Suggest avoiding a lot of pressure. Sometimes, air bubbles and where they reside, aren't easily dislodged by a forceful injection of fluid. In fact, atmospheric pressure (gravity), as reported above, or minimal tank pressure, should be adequate if not real speedy. Attaching a clear/translucent nylon hose onto an open bleeder screw is suggested to observe air exiting from the caliper.

Owners using Castrol SRF will understand as will those who pump the brake pedal and end up replacing an expensive MC.

Sherwood

[rbogh901]

Originally Posted by 911pcars

+1
Bleeding with a pressurized tank seems to do the job for many, but there also seems to be many owners who don't find it very effective (besides circulating many quarts of HD fluid into the trash).

Suggest avoiding a lot of pressure. Sometimes, air bubbles and where they reside, aren't easily dislodged by a forceful injection of fluid. In fact, atmospheric pressure (gravity), as reported above, or minimal tank pressure, should be adequate if not real speedy. Attaching a clear/translucent nylon hose onto an open bleeder screw is suggested to observe air exiting from the caliper.

Owners using Castrol SRF will understand as will those who pump the brake pedal and end up replacing an expensive MC.

Sherwood

Sherwood, thanks. I saw a thread where you posted photos of your gravity bleed set up and now I can't find it. Search search search. Hep me!

[911pcars]

Originally Posted by rbogh901

Sherwood, thanks. I saw a thread where you posted photos of your gravity bleed set up and now I can't find it. Search search search. Hep me!

Unfortunately, the Pelican forum search function has some limitations. A suggestion is to use Google to find forum info. Be that as it may, while a Google search results in many of my suggestions to gravity bleed over the years, none of the links contain the photo in question, so try this:



The bleeding kit is from Harbor Freight and contains a length of plastic tube, bleeder valve adapters and a vented 4 oz. bottle with a weakish magnet to affix to the chassis. In use, with the tube in a vertical orientation, the fluid level only rises to the height of the master cylinder reservoir.

Minimally, all one needs is a 24-30" length of nylon tube that fits snugly over the partially open bleeder valve and a container to store old or excess fluid from the tube as needed. In the following photo, the container is moved lower to collect excess fluid from the system.



Hope this helps.
S

[James Brown]

nifty tool

[dan88911]

Thanks again gentlemen, did it last summer.
I did pretty much everything,Mnez,Neel & RSTarga mention.

I use vise grips on the reservoir vent hose.
Great! photos 911pcars.