does anyone have any tricks in bleeding rv10 brakes? I have bled brakes from pressurizing bleeder screw on either side - have tried the "car method" of pumping, holding the pedal down, & opening bleeder screw. Still have small amounts of air bubbles around the area of the pedal cylinders.
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Bleeding RV-10 brakes
- Thread starter glenn72pc
- Start date
rv6rick
Well Known Member
Piece of cake:
- take off the reservoir breather cap
- hook up your pump hose to left (or right) brake bleeder
- loosen fitting about 1/2 to 3/4 turn
- pump fluid till you see it in the reservoir with NO air coming through
- when satisfied close the bleeder
- repeat for other brake
- reinstall reservoir breather cap
No 'pumping' of the pedals is necessary.
Takes about 5 minutes if your top cowl and wheel pants are off.
- take off the reservoir breather cap
- hook up your pump hose to left (or right) brake bleeder
- loosen fitting about 1/2 to 3/4 turn
- pump fluid till you see it in the reservoir with NO air coming through
- when satisfied close the bleeder
- repeat for other brake
- reinstall reservoir breather cap
No 'pumping' of the pedals is necessary.
Takes about 5 minutes if your top cowl and wheel pants are off.
Mike S
Senior Curmudgeon
Rick has it correct, ---only here is a tip to help keep the mess down.
Screw a barbed fitting into the top of the reservoir, hook a hose a couple of feet long onto it, and put the end in a clear container with enough brake fluid to cover the end of the hose.
You can watch for bubbles, and the mess is caught in the container.
Mike
Screw a barbed fitting into the top of the reservoir, hook a hose a couple of feet long onto it, and put the end in a clear container with enough brake fluid to cover the end of the hose.
You can watch for bubbles, and the mess is caught in the container.
Mike
Rotary10-RV
Well Known Member
glenn72pc said:
Glenn,
I haven't done a 10 yet, but I will in the future as a 10 builder. I am going to relate to you a method that has always worked for cars, motorcycles, and other friends planes. You need a small container into which you can drain clean brake fluid. You need a length of hose that will reach from the bleeder into the can, to the bottom. Clean that hose with alcohol and let it dry. Clean the container like it was your brake fluid reservior. Put some fluid in the container that will cover the end of the hose. Get some grease to put around the nipple to seal the threads. Doesn't mater what kind, it is just to seal the air out. A VERY SMALL amount does the trick. Oh yes I forgot this trick works best if you do both wheels at once although you don't have to. (another container and hose of course.) Then put the hose or hoses in the fluid in the containers. I use metal coffee cans as they stay in one place well and are easy to clean. Fill fluid in the feed to the brakes. If you have a in the footwell/under panel reservoir you may want to set up a remote that will hold more while bleeding. I've used a quart bottle and a bit of copper tubing attached to the standard master to reservoir hose. Crack the wheel fittings.
make it a good 1/4-1/2 turn. Assuming the plane is on the gear the feed reservoir is above the wheels the fluid will run down hill into the other containers. Let it run through for a while. If you cleaned the lower containers you can save the fluid. If you use a transparent line from the brakes to the lower cans you can see the bubbles coming out. Keep running fluid through until the bubbles stop and the lines run clear for about 5 minutes at a time. Close the bleeders, connect and fill the regular reservoir and you're done. It sounds too simple to work but it does. Takes longer to describe than to do! One other thing don't let the feed canister run dry or you will have to do it all over. This was the ONLY way I was successful at truly purging the air from motorcycle brakes.
Bill Jepson
ScottSchmidt
Well Known Member
That is great advice. I also have tried and tried to get all the bubbles out. I was told to pump from the bottom and suck off the top but that never worked. I got to the point where I had only a couple of bubbles and my brakes have always been solid.
I just figured the bubbles made the plane lighter.
I just figured the bubbles made the plane lighter.
L.Adamson
Well Known Member
I used the method as Rick decribes, but with a cheap hand pump garden sprayer from Lowes. Also used the fitting & clear tubing attached to the reservoir and into a clear bottle as described later.
Just sit back and watch it fill. This method removed all bubbles, as I had several from a previous fill several years earlier with a hand oil pump.
When complete, dip the tubing into the reservoir, and pinch it closed to remove a bit of fluid.
L.Adamson
Just sit back and watch it fill. This method removed all bubbles, as I had several from a previous fill several years earlier with a hand oil pump.
When complete, dip the tubing into the reservoir, and pinch it closed to remove a bit of fluid.
L.Adamson
tape clear tubing line to the winshield so you can watch the bubbles go by.... place one end of the line on the wheel cyl. fitting. And the other end into the reservoir. You will recycle the fluid. Now if you have a hand brake, just pump it till the fluid is solid passing your view. Done.... Now do the other cyl. The fluid flow is fast, and the bubbles will be pushed out................
Bleeding Brakes
Glenn,
Bleeding brakes from the bottom up works great but you may have to do it a couples of times to get those last bubbles out. Once you think you have it, put everything back to flying condition and them pump the brakes several time to see how they feel. They will start out hard but if there is still some air in the lines it will not take long for them to feel soft again. I had to bleed mine several times to get all the air out. It will work, just keep at it.
Glenn,
Bleeding brakes from the bottom up works great but you may have to do it a couples of times to get those last bubbles out. Once you think you have it, put everything back to flying condition and them pump the brakes several time to see how they feel. They will start out hard but if there is still some air in the lines it will not take long for them to feel soft again. I had to bleed mine several times to get all the air out. It will work, just keep at it.
Rotary10-RV
Well Known Member
ScottSchmidt said:
<rant>
I also should mention I will use braided ss teflon hoses (-3) all the way to the brakes. I'm not sure what comes with the 10, but the nylon **** that comes with some of the kits out there is a hazzard. I also think the idea of using a service loop in a soft aluminum tube is an accident waiting to happen. Coming to aircarft from the racing world I was appalled by how awful kit aircraft brakes have been plumbed. I also know of at least 2 planes that the recomended system caused a brake failure. I simply DON'T CARE IF THIS WEIGHS 2 OZ more! Like Scott I'll keep a few bubbles if I have to!
<rant over>
Bill Jepson
Deems Davis
Well Known Member
Some residual bubbles
This post was very timely for me, I had initially tried the 'auto method' and found numerous unavoidable bubbles. Last week I followed the steps outlined above, Sprayer pump attached to the brake caliper, barbed fitting screwed in the res, tube attached to 'catcher' bottle. While the process works, it wasn't a 5 min effort for me, in fact I spent 5 hours. I found that the brake cylinders themselves, seem to trap air bubbles, and will allow fluid to move through while retaining the bubbles. I did find that positioning the peddle/cylinders as near vertical as possible helped. I went through untold cycles of bottom up bleeding, accompanied by pumping of the brakes, and still ended up with a 1/2" bubble in each line where the lines cross over the rudder peddles on the copilot side. (At one point I even reversed the process and tried applying a vacuum to the res. (didn't help/change). The brakes are solid and seem to be holding. I'm not looking forward to repeating this if necessary
This post was very timely for me, I had initially tried the 'auto method' and found numerous unavoidable bubbles. Last week I followed the steps outlined above, Sprayer pump attached to the brake caliper, barbed fitting screwed in the res, tube attached to 'catcher' bottle. While the process works, it wasn't a 5 min effort for me, in fact I spent 5 hours. I found that the brake cylinders themselves, seem to trap air bubbles, and will allow fluid to move through while retaining the bubbles. I did find that positioning the peddle/cylinders as near vertical as possible helped. I went through untold cycles of bottom up bleeding, accompanied by pumping of the brakes, and still ended up with a 1/2" bubble in each line where the lines cross over the rudder peddles on the copilot side. (At one point I even reversed the process and tried applying a vacuum to the res. (didn't help/change). The brakes are solid and seem to be holding. I'm not looking forward to repeating this if necessary
Rotary10-RV
Well Known Member
Deems Davis said:
Deems,
One of the reasons I use the "gravity method" is that pumping the fluid can cause cavitation. If that happens the void caused will almost always form a sticky bubble. I have tried EVERYTHING including submerging the brake sytem and assembling! (Too much fluid and messy to clean up.) The down flow works, but will take at least 1/2 hour, more commonly 1-2 hours if you haven't done it before. Keeping the fluid low energy helps to prevent cavitation caused bubbles. Most methods will work, if you're careful. If you do decide to use a pumping system, keep the pressure low and go slow. This will prevent most of the common errors.
Bill Jepson
Just want to be clear, with this method we are pushing fluid UP from bottom bleeder to the reservoir. Correct?
rleffler
Well Known Member
Yes. It only takes a minute or two.
I also add an extension tube using a fitting attached to the reservoir. The tube goes into a bucket to catch the excess fluid. It also allow you to see the level and bubbles better.
Last edited:
Wayne Gillispie
Well Known Member
A pressure pot/modified garden sprayer from ACS worked great. Don't forget to syringe a little fluid out of the resorvoir to allow for expansion and mark the level with a sharpie on the outside. Good to check level at condition inspection. Mine has hardly dropped because I rarely use my brakes.
Worked very well for me, exactly like that and yes about 5 minutes for both of them. The bubbles in the tube between the right and left side really do not impact the brakes, it is not a pressure line . You might be able to get the bubbles out at first but they will reappear. I used a teflon hose in the cockpit for the cross overs and now I can't see the bubble but I know they are there because of my previously built RV-8 with stock nylon see through tubes.
I never could find a hand pump that wouldn't leak all over, so I decided to pressurize my brake fluid can. I know the can looks a bit unhappy after enduring pressurization.
