Flexible brake lines

N811AK

Looking to put a flexible line section between the calipers and the solid line up the gear leg. Need advice for which hose to use.

dekky111

dekky111 said:

N811AK

Looking to put a flexible line section between the calipers and the solid line up the gear leg. Need advice for which hose to use.

dekky111

Click to expand...

The correct hose to use will be Aeroquip 303 (3000 psi medium pressure aviation grade hydraulic hose) with Aeroquip 491 hose fittings.

Some people use low pressure fuel line hose, other buy cheap Chinese auto hoses with no pedigree. Go with the 303 and correct fittings and you can rest assured you have the best.

I used Earl's SpeedFlex hose with appropriate fittings. Comparable to the Aeroquip hose mentioned above..

33 1/2 " long. This is for a RV7/A

Brake Lines

I have used the Racing brake lines from Pegasus. 3000 pound rating and an overall SS braid. You can make your own without special tools or buy pre-made hoses. It is size -3.

http://www.pegasusautoracing.com

pczar3
Paul
N694BP - reserved

pre made brake lines

I am using a standard product from Pegasus, part number 4-36-S-S, which is a 36 inch size 4 TFE hose with straight swivels on both ends. It fits a RV7a fuselage fitting to wheel brakes prefectly and the cost is $19.99 each. Check it out.

Tom Lewis
RV7a

or...once again

Go down to your local hydraulics shoppe...If your town has a farm within 50 miles there will be one. They can get you any hose your heart desires at a fraction of the cost of anything with "Aeroquip" printed on it and its good quality stuff.

Frank

frankh said:

Go down to your local hydraulics shoppe...If your town has a farm within 50 miles there will be one. They can get you any hose your heart desires at a fraction of the cost of anything with "Aeroquip" printed on it and its good quality stuff.

Frank

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Good quality you say.....well maybe...but how do you know that if there's no manufacturing specification you can validate and the source of the product is unknown. It might just be el cheapo hose and cast fittings from China (and probably is). And if you get lucky and it works OK this time how do you know that you're still buying the same quality next time. At that stage your local hydraulic shop might not be getting their hoses from China...they might be sourcing a better price from Somalia.

When builders buy milspec they're buying QA. After all...it's an aeroplane, not a farm tractor, despite what some people may say about Lycoming engines.

brake (farm) line hoses

Builders,
I have been a farmer for a long time. I have had a lot of Hydraulic hoses made by my implement dealer. I have not had one fail that was not abraided by rubbing against some moving part. In other words not one has failed due to the tractors 2,500-3000 psi hydaulic system. There is nothing wrong with the hoses that you can get custom done at a farm implement dealer. Many of the tractors manufactured today use hydraulic pumps from the areo space industry. I.E. aircraft hydraulic pumps.
I don't think you need worry.
Regards,
John Stiegelmeyer

Hydraulics shoppe

I got the tip from a bunch of airplane builders who consider if they have to go anywhere else other than the Hydraulics place, they have failed.

Remember you won't get aluminium fittings and they hoses they sell are rated higher than the Aeroquip stuff (or so I am told). You also will not get anything but swaged on hose ends.

Anyway the good ole boys from round here cannot point to a single failure in building airplanes since the '60s.

It probably more like Aeroquip de-rate standard hoss and triple the price.

Frank

Here's an option...

Go to this link and scroll down until you see the "Brake lines etc." entry. Note that AN3 size works nicely for this application, no need for AN4.

Just an interesting note.

When I was fixing planes to feed the family I was working on a 421c, it had a big hydraulic pump "certified", made by "John Deere" I found this out when I called the Cessna tech rep about a possible problem of it sucking air and messing up the hydraulic air conditioning system. That's when he told me who manufactured them for Cessna, for that purpose.

Ok this is even weirder, I have had farmers coming into my store holding Hydraulic pumps with a Cessna Name Plate on them, wanting to know if I could help them find parts to fix their tractor.

hooda thunk it.

Whatever you do dont use un-reinforced hose that looks like pitot static line, ANYWHERE but for pitot static line.

This is what manyof my walk in customers come in wanting to replace on their homebuilts, and there comments are

"I dont care what it costs I just dont want to lose my brakes again!"

frankh said:

Remember you won't get aluminium fittings and they hoses they sell are rated higher than the Aeroquip stuff (or so I am told). You also will not get anything but swaged on hose ends. Frank

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Actually, contrary to what many might believe, the Aeroquip screw in hose fittings are considerably more reliable than swaged fittings....and in many cases they're re-useable (very handy if your new hose is the wrong length !!!).