one man brake bleed help (trying a gravity bleed?)

[ryanschillinger]

When I was out of town and the Civic's brake master went out, I bought a replacement and a few tools to do the job. Then realized I didn't have anyone to help me bleed it after install! I gravity bled the fronts for a while and left a big puddle in the hotel parking lot. Couldn't reach the rears because I didn't have a jack. Next day, met up with a guy on another forum and we jacked it up and bled all 4. There was no more air in the fronts, but obviously the rears took several bleeds to get air out.

 

[HTSS_TR]

Originally Posted By: The Critic
IME, gravity bleeds are inconsistent. I usually gravity bleed each corner for about 5 minutes after using an air-operated vacuum bleeder since I've found that vacuum bleeders usually leave behind a tiny bit of air. What happens is that a small amount of air enters the system thru the threads when you "suck" fluid out of the blender screws.

Yes, there are some air leak from the threads of bleeder screw, but that air leak is sucked into the vacuum container along with brake fluid.

It is against the law of physic for air to travel opposite direction of brake fluid.

I done many brake bleeding for my cars with Mityvac 7201, never had any air in the system after done. One thing I did was keep the Mityvac operating while closing the bleeder screw before remove the vacuum tube. This way no air can get into brake system.

 

[Merkava_4]

Originally Posted By: slacktide_bitog
You should get speed bleeders. They include a check valve that lets air out but not in

I tried those and they suck. They let air in past the threads when the brake pedal releases. Defeats the whole purpose.

If they made them to where you could leave them tight while bleeding, that would be different.

 

[Vikas]

Quote:
If they made them to where you could leave them tight while bleeding, that would be different.
Hey, that is great idea! It should be spring loaded, so that only when you are actually bleeding the brakes, it will let the fluid out.

Am I right?

 

[stephen9666]

I've successfully used speed bleeders on several vehicles. There are simple ways to prevent air being sucked in around the threads. In my case, I just followed the instructions and didn't fully unscrew them. You can also seal the threads if needed. .

I've also used the little one-man bleeder bottles.

 

[Merkava_4]

Originally Posted By: Vikas
Hey, that is great idea! It should be spring loaded, so that only when you are actually bleeding the brakes, it will let the fluid out.

Am I right?


Yes, something spring loaded like a ball check valve.

 

[Vikas]

Woosh; that went over the head :-(

 

[jrmason]

Originally Posted By: Vikas
Woosh; that went over the head :-(



I see what you did there, LOL. You would have to have a threaded cap that sealed or prevented the spring from opening during normal braking use.

OP, if your only worried about doing a bleed job solo one time I'd recommend the ice scraper or a board cut to length jammed in between the seat as mentioned above. You can fine tune it with the seat adjustment. Even better if you've got electric seats. I've done many over the years that way and it is effective yet time consuming. Just make sure you use a thick rag to protect the seat.

I do enough brake jobs solo that I bought a Motive Power Bleeder. It's the cats meow and I can do a whole system in a matter of minutes.

I would in no way flush a brake system from the bottom to top. The worst brake fluid sits in the calipers and is often full of material from degrading calipers, seals, and rubber hoses. The pistons in ABS modules are extremely tight tolerance and sediment is the last thing you want to push through there. The only way to get all the gunk out of a system that hasn't been maintained in several years is to remove each caliper/wheel cylinder one at a time and collapse the caliper with a c clamp to evacuate all the old fluid. Once all 4 corners have been done and buttoned up crack the bleeders open and let the calipers gravity fill. You'll have to leave the MC cap open and probably top it off once or twice to get everything filled back up. Once you've got fluid at all 4 corners your ready to bleed. It might sound overkill to some but it is the only way you are going to get all the old degraded brake fluid out of your calipers. Simply bleeding them will only get a portion of the old contaminated fluid out of them.

 

[Vikas]

Some people suggest clamping the flexible brake hose (vice grip type of tool) while emptying the caliper but I wonder if it is a good idea to clamp the old hose.

 

[andyd]

I use a few feet of clear tubing into a jar where the tube is submerged to create an air lock. To seal the loosened bleeder, I use a dab of grease. I kneel down where I can see the jar and I pump the pedal by hand. When I have a half cup of BF in the jar, I top off the MC reservoir. This is critical. If you empty the MC , you risk letting air into the ABS.

If I am replacing brake lines, I use a gravity bleed to prove my connections are tight. I don't brake test unless I've replaced pads, etc. Once I have a firm pedal. Done

 

[andyd]

Originally Posted By: Vikas
Some people suggest clamping the flexible brake hose (vice grip type of tool) while emptying the caliper but I wonder if it is a good idea to clamp the old hose.
Probably not the best practice. OTOH, If the hose cant handle that abuse, it's not so good anyway. I've done it without ill effect, but I don't endorse it as a practice. Better to use a cap or something.

 

[Vikas]

Quote:
OTOH, If the hose cant handle that abuse, it's not so good anyway.
Actually, I have been fed that same line by the mechanic when I told him not to let the caliper hang by the brake hose! I did not have good comeback to it.

 

[Traction]

The BEST way to stop brake fluid from draining out of the system while it's apart, is simply hold the brake pedal part way down with a stick, or something. When you do that the master cylinder piston blocks the ports from the reservoir. Might get a few drips, but that is it.

 

[Merkava_4]

Originally Posted By: jrmason
I do enough brake jobs solo that I bought a Motive Power Bleeder. It's the cats meow and I can do a whole system in a matter of minutes.


Thanks for the comment, I was thinking about buying one of those.

 

[jrmason]

The only real down side to them is price, on top of the unit you have to buy the different adapters for the master cylinder. I've got several different manufactures of vehicles so I had to buy 3 right off the bat and ended up buying a 4th to do a family members vehicle. The upside is now I can bleed virtually all makes of vehicles by myself and it works very well.

There is also clean up. I might go weeks or longer in between using it so when I'm done I thoroughly wash everything out with soapy water in a bucket and hang the lines up to dry and turn the container upside down to drip dry. I know a guy who uses his alot more than I do and rarely cleans his out and he has had no problems with it so I don't think it's necessary, I'm just anal like that.

 

[Traction]

The previous comments is why the OTC style air powered vac bleeder it the simplest, easiest, cleanest method out there. No special adaptors needed. The rubber fitting provided fits all bleeder fittings. Just hook up compressed air, pull the trigger, and that's it. Other methods will eventually get the job done, but this thing is just simple, stupid easy. Also, an air powered fluid evacuator would also work well, as it can hold a gallon plus of fluid, instead of only a pint, but might have a little less suction power. The process is as simple as drinking from a straw.

 

[jrmason]

They may be cheaper but that does not mean they are better. I've successfully bled modern ABS sytems with a spongy pedal with my power bleeder after they have been repeatedly vacuum bled. A pneumatic based vacuum bleeder may work for most average jobs but I've proven they do have their limitations more than once.