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Bleeding Beringer Brakes

bkervaski

Hellloooooooo!
Testing
Today I'm planning to bleed my Beringer brakes with their bleeding kit. Looks fairly straight forward, but I can't seem to figure out with the reservoir full and brake fluid in the overflow bottle they provide how to back it down to the appropriate level, any advice appreciated! (I may be over complicating the process)
 
Well, half success.

Right pedal is rock solid, left pedal is really mushy. Bled the left side twice, not getting much air.

Any thoughts?

I was going to remove the bold on one side of the master cylinder to let the piston fully extend (if it's not already, can't tell with it on there).
 
My RV-4 brakes are hard to bleed. Best is if you have a friend to help.

Have one person at the top with with an air pump and a very low pressure. open the bleeder screws ar the bottom while the person at the top pressurizes the full reservoir for a few seconds. Stop the pressure and close the bleeder screws. Repeat until all the air bubbles stop coming out of the bleeder screws.

It is messy, but it works.

X
 
So you're suggesting from top to bottom? I'm currently bleeding from bottom to top (per the instructions). Reversing directions may push out that air?
 
I got the left side to bleed out, fairly equal pressure from right to left on both sides.

First time bleeding brakes, I assume since it's liquid I need to let it set a while for air to work its way out and test again before determining if I need to continue bleeding.

Unfortunately, not sure how hard the brakes are supposed to feel. Got some transition training coming up, I'll make a mental note then.
 
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That is what worked for me on the RV-4 where the brakes are nutritiously hard to bleed.
 
Bleeeding Beringer Brakes

I have Beringer brakes on my aircraft and used the their Brake Bleed kit. I still have the firewall mounted reservoir. This is my method and it works first time, every time.

Certainly it's a two person job and is done from the bottom up. Assuming you have the sintered plug on top of the reservoir, replace that with a suitable hose barb fitting and connect the overflow bottle to it.

The great tip I got from Beringer is to place the master cylinders in the horizontal position when bleeding by removing the lower attachment bolts. I held them in this alignment with cable ties.

Attach the hose from the pressure bottle to the bleed nibble on the brake caliper and by opening the nipple allow the pressure to push fluid through the system. Have the person monitoring the overflow bottle at the fluid reservoir tell you when you have a solid stream of fluid flowing into it. At this point close the bleed nipple and release the pressure form the bottle.

My brakes are as solid as a rock.

I hope this helps
 
Michael,

Thanks for the post. How much travel do you have in the pedals before the brakes engage? Mine are solid but no frame of reference for how much the pedal should move, mine move about an inch or so before they engage.
 
I suggest between 1/4 and 1/2 of an inch. It is quite progressive, no mushiness and no indication that I am riding them during taxi. Those who've flown mine are quite envious of how effective they are. I'm going to my hangar tomorrow so I'll check out the travel before engagement.

I've not used the pressure limiting device but it is installed. I do the bleed sequence with it wound completely off.

Again I hope it helps
 
I bled my Beringer brake with a combination of pressure from a garden sprayer pushing the fluid up from the brakes to the reservoir and suction from the brakes using a harbor freight vacuum bleeder. I this the combo was the way for me to get out all the air bubbles.
 
Hi Bill,
I tried to get an accurate measure of when the brakes take-up after pedal application and as I said, its about 1/4 inch. They really have nice progressive feel. I think you'll enjoy them when you get them right.

I'm building a Glasair Sportsman at the moment. I've installed the standard matco master cylinders but am seriously considering converting to Beringer.,

I'd love to hear what you think when you get it flying

Regards
Michael Brooks
 
Thanks for checking!!! When I press the brakes they depress about 1 inch then stop I may have some air to work out.
 
When I installed a set for a customer I couldn't get all the air out until I disconnected the masters on the lower end and raised the cylinders to the horizontal position (as called out in the manual).
 
I re-bled the system again this morning with the master cylinder's disconnected and in a horizontal position and it made a significant difference. The result was how I would expect them to feel. Glad I make this post and thanks all for the help! :) :) :)
 
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I haven?t bought a bleed kit yet. I?m using the mineral oil type of fluid. Is there any particular pump to buy to pressure the system? Is the beringer kit expensive? What from aircraft spruce gets the job done as well?
 
Most guys on our field (myself included) just use a pump style oil can. Many pumps have a plastic hose with a brass nozzle which can be cut off and the hose then fits the bleeder. Just watch and feel for air as you pump in the fluid. Close the bleeder and refill before pumping any air in. I also level the cylinders prior to starting and connect the overflow to a hose with the end at the bottom of a small bottle with enough fluid in it to prevent drawing air back into the system. Easy to do with one person and no mess if you do it right.

Al
 
RV-4 are special!

There are RV-4's that have the master cylinder mounted the wrong way around. Interestingly the plans show them on one page this way around an on the other page the other way around.

In the end I gave up and re-positioned the cylinder the right way around, so that air can get throu the system and bleeding from the bottom to the top dies not give a mess and only take 5min.

Bleed always from the bottom up ... the bubbles ar going that way also.
 
pump for adding fluid to the brake system

What pump and where did you get it to add brake fluid from bottom up?

I'm ready to add fluid to brand new brake system on RV-7A. I've looked on Amazon, Spruce, O'Rielly's but I don't see a pump that will hold enough fluid to fill up the system to the reservoir.
 
Beringer sells a bleeding kit, it's reasonable and nice quality.

If you are bleeding Beringer brakes be sure to use the correct fluid, it calls for mineral oil, they can send you a gallon with the bleeding kit.
 
Do you recall how much fluid was required to fill the system? I have two quarts and wonder if that is enough. Thanks.
 
Hello Steve

Yes from bottom up ... think like the bubbles ... they will also go this way ;-)

For the absolute first time, I would do this:
- Put a tube/hose fitting onto the reservoir, make a tube into a pot/bin.
- Be sure your brake pedals are fully pulled back (if not, the internal valve is closed and filling will not work).
- Fill each line/side, untill you get some fluid in the reservoir and pot/bin, pump slowly.
- Then pump the pedals a few times, pull the park brake valve a few times and let it open.

Let it sit for a few hours like this, give time to wett all inner parts.

- Open the bleed valve at the caliper, just that much, that it start to drip out fluid, then reconnect the tube from the pump. Also without bubbles in the tube!
- Pump again until you have the brake-system volume exchanged again. Both sides.
- Check that the brake pedals are firm and L and R side equal.
- Disconnect the fitting at the serervoir, take a syringe with a piece of tube and take out 1/3 of the level of the reservoir volume. The reservoir filled to 2/3 is enough.
- Put the Vans sinter cap on.

Done!

Thats it! I have done this on a few RV's without any trouble/mess or all the other storys ... 5min per side only!

Things that help:
- Do not use a "pressure tank bleeder", under pressure you press in small bubbles, that will grow when pressure is released. Exactly what you do not want.
- Use clear tubing from the pump to the caliper, then you see, if there would be a bubble.
- Use also clear tubing and a clear bin/pot that you connect at the reservoir.
- If you could not avoid to let a bubble in ... pump once the system volume thru ... to get it out.

I used a custom made hand pump with a bubble-trap and filter at the exit-line. So I can catch all bubble and dirt going into the system.

I hope this helps!
 
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One quart will do the job ... and you will have plenty to refill for a few years!

Think about, the reservoir is pretty small, then ther is the tube volume which is also not much. Then the volume in the brake caliper.

You need at least double the ammount that is in the system, this only to purge all air out. So with one quart you will be fine.
 
How to fill brake lines with fluid

Dominik
Thanks, excellent write up. This is great addition to the forum. Just what I needed. Much Appreciated.
 
How to fill brake lines with fluid

Dominik
Thanks, excellent write up. This is great addition to the forum. Just what I needed. Much Appreciated.
 
I?m having a really tough time getting my Beringer brakes bled. When you folks say 1/4 inch travel is that master cylinder piston or top of brake pedal? I?ve tried pressure from the bottom, suction from the top and both at the same time. I?m thinking I?m going to need to burp the actual lines where there is possibly air. Any additional suggestions would be appreciated.
 
Disconnect the bottom of the cylinders and position them flat then try to bleed, this is what got it for me. Laying flat allows the bubbles to work their way out.
 
bkervaski is correct. With the Beringer master cylinders you will have to have them positioned horizontal to bleed properly. Also use 15psi, both of these are in the manual. I bled mine from the bottom and didn't have the cylinders horizontal and got nojoy. Once I put them horizontal the system bled perfectly.
 
Agree with other comments, will add one more: I had to exchange the position of the bleed valve to ensure bleed valve was at the lowest point in the system. Apologies in advance if this is stating the overly obvious but just thought I'd mention it.
 
I'm struggling to think how to get my cylinders horizontal with my RV-10 Control Approach pedals. The cylinders mount to the rear of the pedals, so can't just pull them forward like I guess others are doing. Maybe I can pull them towards the firewall??? I'll have to check.
 
I'm struggling to think how to get my cylinders horizontal with my RV-10 Control Approach pedals. The cylinders mount to the rear of the pedals, so can't just pull them forward like I guess others are doing. Maybe I can pull them towards the firewall??? I'll have to check.

Tim,
I have the Control Approach system as well, I un-bolted the bottom of the cylinder and lifted them to rest on the firewall. They stayed there long enough to bleed.
 
Lifting master cylinders

I'm struggling to think how to get my cylinders horizontal with my RV-10 Control Approach pedals. The cylinders mount to the rear of the pedals, so can't just pull them forward like I guess others are doing. Maybe I can pull them towards the firewall??? I'll have to check.

I was wondering that very thing. Which way works best. Lifted forward or aft? Lines facing up or lines facing down?
 
I was wondering that very thing. Which way works best. Lifted forward or aft? Lines facing up or lines facing down?

I disconnected the lower bolts and tipped them up. The way they attach to standard pedals, this put the banjo fittings facing upward.
 
I’ve got my brakes working fairly well but still wondering if they are good enough. The top of the pedals move about an inch and a half. The cylinders move between a quarter and half of an inch. Once engaged they seem firm and hold pressure well. Is that consistent with others with beringer brakes?
 
Albeit on and RV9A, I've got about 1/4" to 1/2" travel with no tendency to ride the brakes. They've got 70 hours on them and I can't say I've noticed any appreciable sign of deterioration. I have not bled them since the initial installation.

I have the pressure reducing/anti lock valve backed off. I wonder if you may have that turned up at all.
 
I’ve got my brakes working fairly well but still wondering if they are good enough. The top of the pedals move about an inch and a half. The cylinders move between a quarter and half of an inch. Once engaged they seem firm and hold pressure well. Is that consistent with others with beringer brakes?

I'd say mine move around 3/4 - 1" at the top fully compressed. I think you have to rely on the "feel" to tell you how they are working: Mine have a definite firmness and a very distinct end-point which comes well before the travel limit (before the springs on cylinders fully compress), and are quite even side-to-side. I had the same sort of concerns as you do, until I had a small leak and noticed a "spongy" feel on one side - after fixing the leak/re-bleeding, the firm feel came back and I was more comfortable. Running engine while setting prop RPM, the brakes held and the airplane actually skidded a bit until the cable I tied down to tail got taut (that was very momentary FYI just to get prop set).

Now that I'm flying brakes just feel "right", don't think about it much. I do test the pedal feel as part of every "GUMPS" check before landing.
 
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So I used the pressure bleeder method and have the right brake done in about three minutes. However, the left brake is proving impossible. I can't get any movement of the fluid at all, even at 15 psi. I have the master cylinders horizontal and confirmed both are open. I have a parking break and confirmed it's open as well. Any ideas? I'm banging my head here. Literally. On the flap bracket every stinking time.
 
So I used the pressure bleeder method and have the right brake done in about three minutes. However, the left brake is proving impossible. I can't get any movement of the fluid at all, even at 15 psi. I have the master cylinders horizontal and confirmed both are open. I have a parking break and confirmed it's open as well. Any ideas? I'm banging my head here. Literally. On the flap bracket every stinking time.

Sent you an email.
 
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