H

hiddenhearth

Member
Some of you may have been following the progress of rebuilding master cylinders and installing ACS-600 brake reservoirs on my RV-6. After removing the four MC's for rebuilding I discovered that the brake lines that run from the co-pilots side to the pilots side brakes are made of the same low pressure plastic tubing that ran from the reservoirs to the co pilots MC. I want to replace this tubing with something more substantial that will not leak. Any ideas, will I need to swap out the fittings on the MC as well?
 
If you are using the heavywall plastic tubing with the brass inserts, that type of line should be fine. As long as you are in the position to replace the lines, order new line and fittings from Van's. Get the lines and fittings currently supplied for the 7(A), part numbers:

Tube: PT-062X1/4Xlength (9 or 15 ft)
Elbow: F69-F-04X02
Insert: F63-PT3-25

I have not had any leakage in two years. I used the plastic tubing from the reservoir, the co-pilot MCs, through to the pilot MCs, then the hose and 1/4" AL tube. The brass inserts slide into the plastic tubing to prevent the tube from collapsing and causing leakage.

Roberta
 
While we're on the subject

Speaking of brake lines, does anybody know why the design uses plastic tubing for most of the lines but braided steel/rubber hose for the last bit?

Thanks,
Martin
 
They have the higher rated stuff for the pilot controls. Everything behind the Pilot pressure hoses is just reservoir for the pilot MCs. The plastic is on the passenger side. I guess the weight savings was considered and they felt the pilot would be doing most of the braking anyway. The plastic is more than adequate. If it fails, you will know due to the fluid on your feet. We have the option to put something more permanent, if we choose, but at a weight sacrifice. Doesn't seem like much there, but it really all adds up overall. You'd be horrified the amount of weight built into a plane by just a few(?) minor items innocently added. I added about 75 lbs to my Searey with stuff that I thought was inconsequential. I kept to the plans on my RV-7A and came in at 1117 fully finished and painted with interior and sound proofing, gyro panel, and C/S prop.

Roberta
 
I don't like the plastic hoses one bit. All certified aircraft use regular 3000PSI burst hose with flare fittings. That is what will be in my -7.
 
Teflon brake hoses

These guys have teflon hoses with AN-3 ends pre-made to lots of different lengths... should do the job nicely.

http://www.pegasusautoracing.com/ProductSelection.asp?Product=3

The plastic tubes can leak if subject to high temperatures (AZ... ;) )

The Bakersfield bunch found this out when Van used the plastic hose all of the way to the wheel cylinders in his early RVs.

gil in Tucson
 
Gill, any idea the difference in weight? Glenn down the road in Tucson. -9A fuse about to do brake lines.
 
reservoirs

I have been following the threads relating to the use of individual reservoirs mounted at the rudder pedals. There was some concern about the resevoirs not clearing the firewall. Has that been resolved?

I am about to do the brake lines on my 8A and would consider the individual resevoirs if they will work. I have the in adjustable pedals. Have any of you 8 guys tried it?
 
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