Can I use a vacuum bleeder to bleed Z51 brakes?
 

It's time to change my brake fluid. I'd like to do it without an assistant if possible (and I don't want to buy a pressure bleeder). Can I use the old fashioned hand vacuum pump to bleed the brakes on a Z51?
Thankls

Yup... do mine once a year.

I tried bleeding my brakes today (doing a brake fluid change) with a Mityvac. I couldn't get it to work. If I have the bleeder just barely cracked (outside bleeder on right rear wheel) then I just pull a vacuum with no fluid coming through. If I open the bleeder a little further air just sucks past the bleeder threads. I got a tiny bit of fluid initially (it was gravity flowing).
Is there a trick? I have successfully bled other brake systems using a Mityvac. Does it matter that I have the parking brake engaged?
Thanks

I've never been able to get satisfactory results from vacuum bleeding.

Bleeding brakes without tech tool doesn't bleed ABS system. I have a vacuum bleeder that hooks to my compressor. But I will pay dealer to do mine. If there is a problem I have a dealer to correct it.
z51vett
Doug

Same here. I just use a pressure bleeder. VERY CAREFULLY. I've pushed air into my system and that sucks.

I have Speed Bleeders on each of the eight bleed points on my 2015 Z51.
I have tried vacuum pump bleeders, hand pump vacuum bleeders and master cylinder pressure bleeders.
Now I simply use the brake pedal and the speed bleeders. I use a 2L soda bottle with a clear plastic tube as a catch bottle.
Neither wife or ex wife ever wanted to be part of brake bleeding. With the Speed Bleeders it is a one person job.
As mentioned above, you must never let the fluid level in the master cylinder get low. You will be in a world of hurt.
Refill the master cylinder after a few brake pedal pushes on each wheel. Err on the side of caution.

I never have found a way to bleed the brakes without removing the wheels. That becomes the biggest part of the job.

I've been able to reach back and do it... It's annoying so I rather pull the wheels.

I haven't had much luck with vacuum bleeders either. I went ahead and invested in a pressure bleeder -- makes it super easy to do by yourself . . . well worth it to me since I have to bleed my brakes several times a year.

You can easily make a pressure bleeder with a 1 gallon garden pump sprayer, some vinyl clear tubing, and a spare master cylinder cap. You drill a hole in the cap to which the vinyl tubing fits tightly through (so it is air-tight).

I bleed my Z51 using the Motive pressure unit. And yes removing the wheels is the hardest part honestly. I use a pass through socket so the fluid line and wrench can in place on - a few clicks to drain, then a few clicks to tighten, reduces the mess slightly. Since I track my car bleeding the brakes is a common task so anything that makes it easier is welcome.

Glad to hear the speed bleeders work... might give that a try one day.

Invest the $60 in a Motive Power Bleeder instead of a vacuum bleeder. You'll be glad you did.

I've tried the Motive Power Bleeder, Hand pump vacuum bleeder and a Vacuum bleeder for the air compressor.

In my world, the air compressor bleeder worked the best out of the three. But nothing beats a person pressing on the brake inside the car.

I have used a Mityvac 7300 PneumatiVac Air-Operated Fluid Evacuator - no issues. As the other posts mentioned, that alone will not get the ABS. You need the GM Scan tool to activate it to clean that out.

I call this the MacGyver method.

I thought I'd give an update for others that find this thread. I was able to use the Mityvac to bleed the brakes.

I had to use Teflon tape on the bleeder threads (per the Mityvac manual). I was hesitant to do this initially because I didn't want to risk contaminating the brake system but I CAREFULLY put Teflon tape on just the bleeder threads.

The other thing I found was the diaphragm in the master cylinder cap is very stiff. I had loosely set the cap back on the master cylinder to prevent contamination and found that it had sealed and "sucked down" slightly. I heard a slight vacuum release when I removed it. This can be used to your advantage to prevent gravity draining of the fluid while the bleeders are out or open.

I'm probably going to keep my eye out for a pressure bleeding system at a reasonable price. I have 4 vehicles with 4 different types of caps (of course). I'd want to find one that will work on all of my vehicles.

" Yup... do mine once a year." Seriously? I hope you're a hard-core racer. :lol:

The Motive is designed to take different caps. They sell just the unit, or the unit plus one cap and of course separate caps.

The only complaint I have with it is the main container is a smooth round object and with greasy hands you can't grip it very well. Something like a milk jug handle on the side would be great.

And the fact it takes like 50+ hand pumps to pressurize. I need to make an adapter for my tire pump.