Brake Charging

About the middle of last week it occurred to me that for the last year I could have gone ahead and charged up my brakes.  I wish I would have done this prior to installing some panels and interior pieces.  Having some of these in place complicated the process a bit.  I didn't think about it at the time but there's a was a good chance, being my first plane and all that I didn't have all the connections as tight as I should have.  More about that in a bit.

Apparently there are several methods of filling the system with hydraulic fluid and bleeding the air out.  My previous experience was on motorcycles which was basically put the fluid in the reservoir and hammer on the brakes until they work.  I decided to watch several videos on the subject and the one from EAA I found the most informative.

I reviewed the Matco documentation for the type of fluid needed and went ahead and ordered everything.  Essentially it was $14 for a quart of Royco 782 Hydraulic fluid and another $10 for a pistol oiler off Amazon.  So for roughly $25 I was ready to go!

The video laid out how to fill it from bottom up, having someone watch the reservoir for when it overflows.  Seemed easy enough and I had some extra static line tubing which worked well to connect to the Matco fittings.  Attached it, loosened the nut and got to pumping.  I immediately noticed some fluid coming from one of the fittings so promptly tighten that up.  Should note that I had torqued this previously but apparently either I did it wrong or it wasn't enough.  I got back to pumping, after about a 1/3 of the quart was used I got a bit concerned and removed the seat panel.  Well there was the fluid, all over my foam insulation and starting to go all over the place.

Found the leak, tightened the fitting and went around and tightened a few more fittings and starting pumping again.  As I was pumping I was looking for leaks and found another one on the parking brake fitting.  Luckily I had the forethought to remove the forward carpeting so it was an easy fix and clean up.  I then double checked that I had the parking brake open, and pressed on.  After a bit there was more fluid coming out of the reservoir, down my firewall and all over the garage floor.  More clean up....

After that I got to the right one and went through the same steps.  It seemed to have taken a lot of fluid, so I spent a lot of time trying to look inside my tunnel through the side access panel so I didn't have to take off my throttle quadrant.  It's doable, just didn't want to do it if it wasn't needed.  Hence why if I did this when it was all open, it would have been easier.  Anyhow after awhile it started coming out the reservoir as well.

I made the decision at this point to go ahead and remove the foam insulation I had put under the seat.  It's a bit hard to find leaks with this stuff, it also probably absorbs liquids and I foresee going through a similar process once I connect the wings and fuel lines.  To be honest the RV-10 I'm flying now has zero insulation, just leather interior and I don't find it particularly noisy or anything.  Or at least nothing the ANR headset can't block out.  Anyhow it was a mess to get the foam out, there's still some sticky tape pieces I'll have to pick out later, but I was at least able to get a majority of the liquid out.

Testing is pretty simple.  I climbed in, had someone watch the reservoir and pumped the brakes on both sides.  Not having them rigged makes them push back a bit too far and expect some extra fluid to come out and you actuate them.  I did this several times to ensure later when I close these up that I'm not going to end up with hydraulic fluid all over my firewall.