View Full Version : Brake Bleeding using Mity Vac


FuzzyLog1c
06-17-2012, 12:11 PM
Hey--

Just installed the Goodrich stainless steel brake line kit. I found several sets of one-man tutorials on brake bleeding. Picked one for use with my Mity Vac hand pump. Unfortunately, it didn't work, and I have little-to-no brake pedal.

I checked for leaks in the system, but the fittings are all solid, with the exception of the caliper valves, which might need a Teflon wrap on their threads to prevent air from getting in the system.

I'm guessing that my methodology is off. Could you take a look at this and see if you can spot a problem?

1. Standard bleeding order (right rear to left front). Keep the master cylinder full at all times.

2. Using Mity Vac, apply vacuum to the inboard valve. Crack the valve, pump the brake pedal a couple of times, and then close the valve.

3. Rinse and repeat for the outboard valve and then the rest of the calipers.

4door-6speed
06-17-2012, 12:25 PM
Hey--

Just installed the Goodrich stainless steel brake line kit. I found several sets of one-man tutorials on brake bleeding. Picked one for use with my Mity Vac hand pump. Unfortunately, it didn't work, and I have little-to-no brake pedal.

I checked for leaks in the system, but the fittings are all solid, with the exception of the caliper valves, which might need a Teflon wrap on their threads to prevent air from getting in the system.

I'm guessing that my methodology is off. Could you take a look at this and see if you can spot a problem?

1. Standard bleeding order (right rear to left front). Keep the master cylinder full at all times.

2. Using Mity Vac, apply vacuum to the inboard valve. Crack the valve, pump the brake pedal a couple of times, and then close the valve.

3. Rinse and repeat for the outboard valve and then the rest of the calipers.


I have had this problem before with the Mity-Vac. I have used teflon tape with marginal success. If you try this be sure not to get any tape on the bleeder valve sealing surface.

For Item 2 I would not "crack the valve and pump the peddal" this may let air back into the system from the leaking bleeder valve threads.

I have resorted to the two man method with the help of the wife.

BTW you'll like the braided lines when you get the system blead.

Glenn

heavymetals
06-17-2012, 12:35 PM
You may have to pump a lot to get all the air out and forget it if you get air in the ABS unit.

The reason why I went with the "Blue" fluid is so I could see when the old fluid was purged.

I used a Motive "Power Bleeder", which required no pumping and was a "one man" job.

I did however have to bleed the thing twice.

4door-6speed
06-17-2012, 12:39 PM
Heavymetals
Do you have a model number and sourse on the Motive "power bleeder"

TIA

FuzzyLog1c
06-17-2012, 12:42 PM
You may have to pump a lot to get all the air out and forget it if you get air in the ABS unit.

The reason why I went with the "Blue" fluid is so I could see when the old fluid was purged.

I used a Motive "Power Bleeder", which required no pumping and was a "one man" job.

I did however have to bleed the thing twice.

It's possible that I got air in the ABS unit. Did that happen to you?

heavymetals
06-17-2012, 12:49 PM
It's possible that I got air in the ABS unit. Did that happen to you?

I thought I did and was I fucking pissed.

The way to tell (I was told) is to see if you get ABS warnings, which I didn't, but I thought the pedal didn't "feel right" so I blead it again, and did get a couple of bubbles.

I got to exercise the ABS by finding a gravel road and stomping on the brakes, which turned on the ABS.

I got the "shudder" which tells you the solenoids are working as well as the ABS.

Good now, and thanks to the "mod gods" for not making me take it to the dealer for a stupid brake bleeding.

(they have a TECH II procedure that bleeds the ABS unit)

heavymetals
06-17-2012, 12:56 PM
Heavymetals
Do you have a model number and sourse on the Motive "power bleeder"

TIA


http://www.jegs.com/i/Motive+Products/715/0108/10002/-1

01_SuperSlow
06-17-2012, 01:26 PM
If you have an air compressor, this is a real nice one man bleeding tool.
I have it and it works really well.

http://www.amazon.com/Mityvac-MV6835-Vacuum-Brake-Bleeding/dp/B0015POUXM/ref=sr_1_2?ie=UTF8&qid=1339953812&sr=8-2&keywords=mityvac+brake+bleeder

SSmokd U
06-17-2012, 02:13 PM
Crazy that this popped up cause I am preparing to do this right now. I am planning to swap the fluid with new which has never been done on mine. I was under they impression that all I needed to do was pull vacuum with the mity, crack the bleeder, then just keep the mity pumped while making sure the reservoir stays full until I see no more dirty fluid coming out. Is that wrong?

heavymetals
06-17-2012, 02:42 PM
Crazy that this popped up cause I am preparing to do this right now. I am planning to swap the fluid with new which has never been done on mine. I was under they impression that all I needed to do was pull vacuum with the mity, crack the bleeder, then just keep the mity pumped while making sure the reservoir stays full until I see no more dirty fluid coming out. Is that wrong?

That's it.

Just don't let the reservoir gulp air.

Greed4Speed
06-17-2012, 03:50 PM
Bleed your master.

I had this problem when I had my calipers powder coated. I could bleed the calipers all day with no improvement to the pedal. I bled the master and that was what was needed.

4door-6speed
06-17-2012, 09:53 PM
Thanks, Heavymetals and 01 superslow

BudRacing
06-17-2012, 10:56 PM
I prefer speedbleeders over all of the pumps.
www.speedbleeder.com

FuzzyLog1c
06-18-2012, 05:54 AM
Bleed your master.

I had this problem when I had my calipers powder coated. I could bleed the calipers all day with no improvement to the pedal. I bled the master and that was what was needed.

Could you point me toward a tutorial? I've read many threads about bleeding clutches and calipers, but never one regarding the brake master cylinder.

Edit: am I looking at something like this?

http://www.youtube.com/watch?v=vOuDEiwiozQ

Greed4Speed
06-18-2012, 02:37 PM
I just had my wife pump and hold the pedal. I then loosened a brake line fitting to the master enough to let some fluid and air out. Tighten the fitting back up and repeat as necessary or move on to the next.

etcts-v
06-18-2012, 03:17 PM
I've used the Miti-vac several times in the past with great success, including bleeding my clutch with it. One thing that helps to build a seal with the miti-vac hose is to put some grease on the fitting of the brakes before you put the hose of the mitivac on. Then build vacuum with them pump and crack the fitting until the pressure is close to gone in the pump then close the fitting. Re-build vacuum then repeat. Just keep doing that until there are little to no bubbles.

If you are using the peddle pump method, don't pump the peddle with the fitting cracked. Pump the peddle a few times then hold pressure, crack the fitting and let the peddle go to the floor then close the fitting.

Also good idea as the guys above said is to bleed your master, easiest IMO is to remove it from the car and do a bench bleed on it. When bench bleeding you really need two people to get a successful bleed, have one filling the reservoir while the other holds it and presses the piston against the bench.

Cadzilla
06-18-2012, 06:00 PM
I installed some goodridge lines on my V a while back...I've had air in my ABS (or so I assume) since, and it sucks!!!!!!!!!!!! I think I can pump my pedal 15-18 times once the car is off before it's firm.

Heavy's comments make me think maybe I could get the air out with another bleed, but I've used a power bleeder 2 times and once traditional, with no luck.. still a soft, unpredictable pedal.

I might have a weak master too, it seems to have way too much give when the car is off and all the air is out of the booster- like 1/2 inch or so, so it makes me think maybe the seals are toast. I might replace that first.

After that I might just break down and just pay my buddy to use his tech2 one weekend..I have some other things I'd like to use it for anyway.


I will say that the biggest impact I've experienced with better brake pedal feel was ironically stiffer springs and shocks. It takes alot more pedal effort when everything is softer.

heavymetals
06-18-2012, 06:03 PM
Here is some info:

http://www.teamzr1.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=999