Initial brake system fill and bleed - problems

[MED]

Glad you are making progress, Jeff. In the way of encouragement, we used Beringer brakes and parking brakes on our two RV-14s, and after filling them from the bottom, have not had any problems. The brakes are great! You’ll get there.

[jeffw@sc47]

Med,

Did you have the same or similar experience as I described with the multiple and lots of pumping up and bleeding with multiple full over flow bottle fills?

Bled them again this morning and raised the pedal cylinders horizontal and got solid hard pedals. Will check again tomorrow morning and see if they're holding.

[BillL]

Originally Posted by HFS

I make this little "gadget" that goes in the BF Reservoir when bleeding the brakes to automatically maintain the correct "head space" when there is fluid overflow during the bleeding process.

Pretty self explanatory - when the fluid rises to the level of the bottom of the ez-fill tube, it (fluid) continues up through the tube and out to the discharge outlet (connected to a clear vinyl tube - to monitor removal of entrained air). Once the fluid rises to, and "covers" the inlet, the remaining space above is slightly pressurized (to fluid pressure), and remains to yield the necessary "head space" for an operating system.

The fitting shown has a 90* elbow to clear and potential clearance issues with the cowling hinge line. If conditions permit, a straight thru configuration works just fine.

I silver braze all connections, then bead blast to get rid of "overrun" - then paint.

YMMV - but this works for me.

HFS

Good Idea!! and it really works too.

I do the same thing for the same reason. The difference is I use a brass adapter to 1/4" OD poly tubing and drill the inside so the tube will go all the way through. No brazing needed, and I loosen the B nut and allow the fitting to spin when installing. It is directly attached to a small bottle to catch the over flow, otherwise the little bottles always get away and spill. It hangs down where I can see it when operating the bleed valve and pressure cup.

I use a slightly modified less-than-$10 2 liter hand pump garden sprayer to pressurize from the bottom.

[HFS]

Enough said.

HFS

[jeffw@sc47]

After the reservoir is filled and the system bled, I pull about 1.5 ounce of fluid up out of the reservoir with a syringe to create the head space.

[MED]

Originally Posted by jeffw@sc47

Med,

Did you have the same or similar experience as I described with the multiple and lots of pumping up and bleeding with multiple full over flow bottle fills?

Bled them again this morning and raised the pedal cylinders horizontal and got solid hard pedals. Will check again tomorrow morning and see if they're holding.

We set up an overflow bottle at the reservoir and filled from the bottom of each side with a garden sprayer. We did disconnect the brake cylinders at the rudder pedals and oriented them horizontally to help clear any air, as someone on the forum suggested. Then, as you did, we used a syringe to create a little headspace in the reservoir. All in all, it didn’t take very long and we both ended up with solid brakes.

[TS Flightlines]

My friend Ray Ward, many time builder of all sorts of planes, uses this bleeder he bought from Amazon, Used with your compressor and a regulator, bleed from the caliper bottom. Certainly forces all the air out.

Tom

[N49ex]

First: Yes, bottom up is it!!! Forget anything else, both for planes and cars.

Second: You can make yourself a bleeder:
https://www.kitplanes.com/homemade-c...brake-bleeder/

[rv8ch]

I just use one of these, and yes, a bigger one would be better.