Vacuum bleeding

[maxdustington]

Originally Posted by Cdn17Sport6MT
For ea. new car I buy, I buy one additional bleedscrew... in the case of my Mazda6 - one frt bleedscrew, and one rear bleedscrew (cuz they are differnt). I tape it up with teflon tape (not on the seat, just on the threads) so I can have one such screw "at the ready", ready to replace the one I take out. This minimizes fluid leakage... and I then rotate it to very lightly seated by hand. I slip the vac. hose over the nipple, and then I release the "haemostat" (or open the valve) that admits vacuum into the hose. Then I open the bleed screw, oh, about a turn or so (only). Some air bypass goes into the bleed hose... but 'boy does the brake fluid course into the vacuum jar. I have a one quart Mason's jar on a wooden base so as to prevent said glass jar from falling over. This set up has served me for years...
I love how you get extras not because they are going to get corroded in the rust belt, but to have one with sealant on it. We like our rust along with our high housing prices over here in 'Ronto.

 

[buck91]

I absolutely love using my Motiv Power Bleeder. If vacuum bleeding isn't doing the trick for you, check it out.

 

[Cdn17Sport6MT]

Originally Posted by maxdustington
Originally Posted by Cdn17Sport6MT
For ea. new car I buy, I buy one additional bleedscrew... in the case of my Mazda6 - one frt bleedscrew, and one rear bleedscrew (cuz they are differnt). I tape it up with teflon tape (not on the seat, just on the threads) so I can have one such screw "at the ready", ready to replace the one I take out. This minimizes fluid leakage... and I then rotate it to very lightly seated by hand. I slip the vac. hose over the nipple, and then I release the "haemostat" (or open the valve) that admits vacuum into the hose. Then I open the bleed screw, oh, about a turn or so (only). Some air bypass goes into the bleed hose... but 'boy does the brake fluid course into the vacuum jar. I have a one quart Mason's jar on a wooden base so as to prevent said glass jar from falling over. This set up has served me for years...
I love how you get extras not because they are going to get corroded in the rust belt, but to have one with sealant on it. We like our rust along with our high housing prices over here in 'Ronto.

Gotta admit that Vancouver is easy on cars. There is NO WAY I would have a Mazda if I lived in central Canada... They can become rust buckets. For that, I would have a cheaper VW sedan... like a Jetta, or ? - as they are very well rustproofed, in general.

Good that the environment is easy on cars, here... and accordingly, easier on the pocket book. Housing prices, though they have moderated a 'wee bit lately, sure are not easy on finances here!

 

[Cdn17Sport6MT]

Originally Posted by wtd
My Mityvak vacuum bleeder will not pull a vacuum with the hose attached to the bleeder but it will if I put the hose to my hand. I even used a new rubber piece that goes on the bleeder with no results.

That's 'cuz as soon as you try to pull a vacuum with your Mighty Vac - it bleeds-in atmospheric pressure air by the bleedscrew threads. You need to have a vacuum chamber that constitutes a LOT of "negative air pressure" - i.e. a vacuum - before you allow it to be attached to the bleedscrew. Either use a haemostat or a valve on the hose that goes from the vacuum chamber to the bleedscrew.... and then build-up your 25 or 26 inches of Hg vacuum in your reservoir before you start to bleed brake fluid from the bleedscrew. Also, use teflon tape on the threads portion only (not anywhere near the seat-portion) of the bleedscrew to lessen air bypass into the vacuum chamber.

 

[Cdn17Sport6MT]

Sorry, I have used the wrong term... I do NOT mean haemostats; rather, plastic clamps. The concept is the same, though.

 

[pb]

https://www.amazon.com/BikeMaster-Vacuum-Brake-Fluid-Bleeder/dp/B00BQVIF36

i've used this after the frustration of trying the hand pump. had it now for over 10 years.
i would still have a soft pedal after gravity bleed. now i run vacuum all the way till tighten.

 

[SHOZ]

This was on my Hyundai Accent. It does not gavity drain for the rear cylinders. And even with 25" of vacuum it would barely pull any fluid out. I went back to the pump and dump method.

 

[doitmyself]

Originally Posted by SHOZ
This was on my Hyundai Accent. It does not gavity drain for the rear cylinders. And even with 25" of vacuum it would barely pull any fluid out. I went back to the pump and dump method.


I could not get my last Caravan to pressure bleed. I imagine we are having difficulties due to the design of the proportioning/combination valve? There are tools to assist this: https://www.performanceonline.com/GM-Combination-Proportioning-Valve-Bleed-Tool-AC-Delco/

Maybe an expert will chime in to confirm this.