RV-4 brake lines

[ccsmith51]

I have aluminum brake lines. There is a coupler in the line about three inches from the caliper fitting. It is a male-male, and the brake line coming from the firewall is flared and connected to it with a B-nut. Then there is a short tube going from the coupler to the caliper.

I need to replace the brake line as it is leaking at the B-nut. The tube is kinked right at the B-nut ferrule and I cannot stop the leak. The brake line is not long enough to remove the bad part and flare.

Question 1: Is this coupler part of the plans, or something the original builder might have done because of he cut the brake line too short? I think there is one on the other gear, but don't remember.

Question 2: Can I run a brake line directly from the firewall to the caliper fitting?

Question 3: Are there options I should consider instead of the soft aluminum tubing?

Thanks in advance...

[Check6]

For me if it brake lines I would use Bonaco,Pegasus lines (these guys are outstanding to work with!)or racing line of your choice. Yes the aluminum and flare work and are effective, no debate. But from a ease of use, I love these hoses on the struts, etc. It has truly been one of the joys of having an experimental aircraft that IMHO has been a great improvement and one less thing I worry about when stomping on rudder pedals or replacing the brake pads as required. No digs against alumimum and flaring as I know they are effective too. Just my 2 cents.

[blackbeard10]

My brake lines are Bonaco made lines from caliper to pedal. Not that expensive. Worry free and great service from Bonaco.

[AX-O]

CALL BONACO!

Those guys worked with me for what I needed and made me feel like I was their only customer. I ended up adding a plastic sleeve to mine so oil would not get in the braided part.

Question 1: Not per plans. Unless it was a long..long.. time ago.

Question 2: Yes. You will need a loop on the caliper side if you go with aluminum lines.

Question 3: Yes. Per above comment. Call Bonaco. They made me a #3 size line with a #4 fitting. A lot easier to route the line and still have the strength of a #4 fitting. Some pics below. More in my landing gear section of picasa.

[ccsmith51]

Thanks for all the help, much appreciated. I'll give Bonaco a call today and ask them the proper way to make the measurements from the firewall fitting to the caliper and then go from there.

[Stewie]

Chris-
Check out premade -4 hose from Summit:

http://www.summitracing.com/parts/aer-fcc0406/overview/

The 72" hose was perfect length for my RV-4, running from master cylinders (on the pedals) through the fuse side at the cheek, down to the wheel (similar to Axel's installation, but continuous/without the bulkhead fittings). Much cheaper than custom lines. For custom, I'd recommend TSFlightlines.
Eric

[Pat Falley]

I just went through the same drill last week. I used Pegasus -3 lines, 74" long, and used a grommet where they passed through the sides. Ordered them on line, took about a week, under $100 for both. I also needed to change the fittings on the master cylinder and brakes, 90 degree, NPT to flared AN fittings from Spruce.

[ccsmith51]

Originally Posted by AX-O

Can someone tell me if the AN fitting in this photo is an AN822-4D (1/8 thread) or AN822-4-4D (1/4 thread)?

Thanks,

[az_gila]

Originally Posted by AX-O

....

Those guys worked with me for what I needed and made me feel like I was their only customer. I ended up adding a plastic sleeve to mine so oil would not get in the braided part.

.....

Some manufacturers (not sure about Bonaco) sell a braided hose with a PVC exterior sleeve. Ask about this option before you buy.

[AX-O]

Originally Posted by ccsmith51

Can someone tell me if the AN fitting in this photo is an AN822-4D (1/8 thread) or AN822-4-4D (1/4 thread)?

Thanks,

I can't remember. You can look up the caliper and find the size of the hole. thats what I did at the time. I remember having the same question. Sorry!