Right brake lines in contact with firewall

[ravenstar]

I just completed page 32-02, which involves securing the brake lines to the firewall with a cushion clamp. Although everything fits neatly, all 4 brake lines on the right side seem to be in contact with the corner formed by the F-01201B-1 and the F-01201A-1 (middle and upper firewall sections). I'm concerned this will eventually lead to wear and failure of the lines. Has anyone else seen this, and is it a cause for concern? I'm wondering if I inadvertently introduced a twist in the lines when attaching them. It's difficult to see in a photograph, but if you look very closely you can see that they're all pivoting on the corner.

 

[DHeal]

Yes the brake lines do tend to lightly rub on the firewall but in my 1,450 hours of use I can find no discernible signs of wear. If it concerns you I suggest that a couple of pieces of tough slippery plastic tape be installed on the firewall to minimize potential friction and wear. Alternatively a few lengths of spiral tubing wrap could be installed over the brake lines at the potential wear points. Whatever you do, do not restrict the free movement of the brake lines.

 

[funflying]

Yes the brake lines do tend to lightly rub on the firewall but in my 1,450 hours of use I can find no discernible signs of wear. If it concerns you I suggest that a couple of pieces of tough slippery plastic tape be installed on the firewall to minimize potential friction and wear. Alternatively a few lengths of spiral tubing wrap could be installed over the brake lines at the potential wear points. Whatever you do, do not restrict the free movement of the brake lines.

Totally agree with David and I used 3-4inch long clear tubing I split and put over the brake line where these lines rubbed on the firewall. Over time these protective pieces would slide down and not cover the area of concern. I place some small tie wraps at the bottom of the protective tubes and this holds them in place. But there are other methods if you are concerned.

 

[ravenstar]

Thank you both. It's a relief to know that this isn't unusual and hasn't caused a problem. I'll make this one of my routine inspection items and not worry about it, then.

 

[sc_pilot]

If you are concerned about wear of the plastic lines on metal… remember the rudder pedals are a steel tube through a plastic block. Same with the flap arm. And we aren’t worried about those which happen to be in constant motion and clamped with friction. I’d be more worried that the brake lines don’t get too taught when the rudder pedals are at max deflection. That wouldn’t be good to stretch the line.

 

[Webb]

Looks like the clamp can be rotated 180* from the picture. Would this provide the clearance you would like to have?

 

[bobg56]

You can use some spiral wrap if your concerned about friction, Aircraft Spruce sells it in different sizes.

 

[mgrieb]

I’ve flown and/or looked at a number of 12’s. They all have that. I suspect it’s just fine as is. I put a strip of Velcro, the fuzzy side, on my firewall. Good at 400 hrs.