Brake Bleeding Tips

[dholly 718]

OK, because I must really enjoy working in a freezing cold hanger or something, I decided to flush and replace the 5606H fluid in my KF4-1200 brake system.

Bad move.

First, I purchased a 20oz. oiler can with pump for $5 at the infamous HF china import store, hooked up some tubing and had a go at it. Geez o'crap what a messy PITA! That P.O.S. oil can had a faulty back check ball valve and just wouldn't pump hard enough to fill the brake reservoir or keep the fluid from seeping back down to the can. After cramping the hell out of both thumbs and leaking all over the place, lets just say that P.O.S. oiler can is no longer capable of functioning in any capacity.

Second, while not a particularly difficult job on the other vehicles I've done, a number of questions popped into my mind when dealing with the plane's braking system.

So I have a few questions...

Q1.) I can't seem to find a good oiler can that works with the thin viscosity hyd. fluid, most are designed for thicker mineral oils. What do you use? Am I better off just finding a clear plastic squeeze bottle to attach my tubing to? Not too keen on spending $30+ on a fancy brake flush kit from the auto stores given how much use I will give it.

Q2.) I've read that you *must* unbolt the brake ram clevis from the pedal horn, as any pressure on the ram tends to close (open?) the check valve in the brake cylinder and preclude a full fill. Anybody do this?

Q3.) I've also read that you should stat with the longest run (ie., the right side brake) first, then do the other. Why is that, makes absolutely no sense to me??

Q4.) After you remove the dirt cover and open the top bleeder hex head screw, how much fluid do you push through to ensure bubble free fluid? And how do you catch it as it slops out of the top of the brake cylinder reservoir?

Q5.) After you have sufficient brake fluid running down your floorboards to confirm a good fill, do you close the lower bleeder valve but leave the upper bleeder valve open to allow any stray air bubbles to work their way up and out?

Feel free to share your tips please!

[Flugtaxi 17]

OK, because I must really enjoy working in a freezing cold hanger or something, I decided to flush and replace the 5606H fluid in my KF4-1200 brake system.

Bad move.

First, I purchased a 20oz. oiler can with pump for $5 at the infamous HF china import store, hooked up some tubing and had a go at it. Geez o'crap what a messy PITA! That P.O.S. oil can had a faulty back check ball valve and just wouldn't pump hard enough to fill the brake reservoir or keep the fluid from seeping back down to the can. After cramping the hell out of both thumbs and leaking all over the place, lets just say that P.O.S. oiler can is no longer capable of functioning in any capacity.

Second, while not a particularly difficult job on the other vehicles I've done, a number of questions popped into my mind when dealing with the plane's braking system.

Hello, it is easyer for me to answer after your questions, lets go:

Yes I now your trouble, we had something like that... because we opend the false screw from the valve and pressed the syringe :banghead:/>

So I have a few questions...

Q1.) I can't seem to find a good oiler can that works with the thin viscosity hyd. fluid, most are designed for thicker mineral oils. What do you use? Am I better off just finding a clear plastic squeeze bottle to attach my tubing to? Not too keen on spending $30+ on a fancy brake flush kit from the auto stores given how much use I will give it.

For our Matco Brakes we take a 300mm syringe from an drugstore and an clear gasoline fuel pipe.

Q2.) I've read that you *must* unbolt the brake ram clevis from the pedal horn, as any pressure on the ram tends to close (open?) the check valve in the brake cylinder and preclude a full fill. Anybody do this?

No...we didn´t do that

Q3.) I've also read that you should stat with the longest run (ie., the right side brake) first, then do the other. Why is that, makes absolutely no sense to me??

It makes for me no sense too :hammerhead:/>

Q4.) After you remove the dirt cover and open the top bleeder hex head screw, how much fluid do you push through to ensure bubble free fluid? And how do you catch it as it slops out of the top of the brake cylinder reservoir?

Take an second person to help you to bleed the reservoir. Better you take a wife,

reservoirs and oil are natural for them :)/>

Q5.) After you have sufficient brake fluid running down your floorboards to confirm a good fill, do you close the lower bleeder valve but leave the upper bleeder valve open to allow any stray air bubbles to work their way up and out?

yes, in this way it works. We closed the upper bleeder 5 min. later.

Keep on flying, many happy landings, Flugtaxi (sorry for my bad english).

Feel free to share your tips please!

Edited 20 Feb 2013 by Flugtaxi

[dholly 718]

Better you take a wife, reservoirs and oil are natural for them

Lol, your English and sense of humor are just fine Flugtaxi. Thanks for the helpful reply and a good chuckle too!

[EDMO 1078]

Better you take a wife, reservoirs and oil are natural for them

Lol, your English and sense of humor are just fine Flugtaxi. Thanks for the helpful reply and a good chuckle too!

I second that good comment - Your English and humor are sehr gute, Danke.

Much besser than my Deutch and a hell of a lot better than my French or Spanish -

Speaking "Merican" didnt help much when we crossed the big waters!

I really liked the big syringe idea - remembered the big ones we used on the horses and cows for shots and blood samples.

BTW: I finally bought the spring-nose gear that you told me about - Thanks again.

ED in MO

Edited 21 Feb 2013 by Ed In Missouri

[Av8r3400 1179]

Okay. I've done this several times.

1. I don't know. Maybe napa or similar quality auto parts store. I am now boycotting HF. I use a buddies oil can.

2. No. Never heard of such a thing. If the ports aren't open when the peddle is all the way back, you have other problems.

3. Huh? That's nonsense. These are two separate systems, left and right.

4. I watch vent through open door and go just until I see fluid come out of the vent. Any helper would work. Even the wife...

5. As you pull the line off to snug down the bleeder, a little will come back out of that bleeder, this will be enough to give a little air pocket at the top of the res. Then put plug back in res. The res is vented to allow fluid movement so leaving the plug off does little for you but add to the mess.

You're done. Test for hardware tightness and peddle pressure then go flying.

Edited 21 Feb 2013 by Av8r3400

[1avidflyer 1983]

Being the frugal guy I am, I have a mustard sqeeze bottle that I use for bleeding the brakes on the plane. I tip the bottle upside down, so there is just fluid in the clear line and open the bleeder screw and sqeeze the bottle. Works fine and the price was right! Take care, Jim Chuk

Okay. I've done this several times.

1. I don't know. Maybe napa or similar quality auto parts store. I am now boycotting HF. I use a buddies oil can.

2. No. Never heard of such a thing. If the ports aren't open when the peddle is all the way back, you have other problems.

3. Huh? That's nonsense. These are two separate systems, left and right.

4. I watch vent through open door and go just until I see fluid come out of the vent. Any helper would work. Even the wife...

5. As you pull the line off to snug down the bleeder, a little will come back out of that bleeder, this will be enough to give a little air pocket at the top of the res. Then put plug back in res. The res is vented to allow fluid movement so leaving the plug off does little for you but add to the mess.

You're done. Test for hardware tightness and peddle pressure then go flying.

[dholly 718]

Jim, proof great minds think alike! As I was sitting there fiddling around with that cursed oiler can, all I was thinking about was a cheap plastic ketchup/mustard squeeze bottle. They all come with a tapered tip which seems like it would be a cinch to attach a clear tubing hose, even if you have to step the hose dia. down a couple times, and a non-colored bottle would make it easy to see the fluid level. Heck, why not just use a several foot long hose and squeeze from inside the cockpit and leave the wife behind?

Larry, after hearing gurgles with the top bleeder closed I suspected the reservoir was vented, thanks for confirming. I am a little surprised about that though, being open to the atmosphere introduces condensation and water into the system. Ie., I know Glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic and absorb moisture but, if mineral-based fluids like 5606H hyd. and ATF are not, I suppose it poses no problem??

Also, after a little reflection in front of the wood stove last night with 3 Queens in a Tito's Dirty Martini, I think the comment about filling the longest brake line first must refer to a dual brake system with remote reservoir.

...so off to Wally World to pick up a squeeze bottle and some salsa today. Have you tried their fresh garden salsa (hot, of course)? Surprisingly one of the best around, IMHO, particularly when fresh tomatoes are in season...

[Knuckledragger 135]

I just bought these at HF for $2.99:

 

[gregpro50 64]

This is the tool to use. 

http://m.ebay.com/itm/One-Man-Reverse-Brake-Clutch-Bleeder-4-FREE-EPDM-Brake-Bleeder-Caps-/272092445910?nav=SEARCH