Brake pedal return springs

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cjensen
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Brake pedal return springs

Post by cjensen »

I bought these springs with a small group of us local builders last fall, and I finally got around to installing them. Rob Johnson headed this up for us, and he is getting the part numbers together for me, so he may post them here as well.

Image

I'll post the part number for those of you that have asked me if Rob doesn't do it first. They came from McMaster Carr, and were $5 for one pair.

They work great, and are easily adjusted with a set screw. Pretty slick!

Image
Chad Jensen
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painless
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Post by painless »

I highly recommed installing these. I was dragging my right brake slightly for quite some time until I installed mine. Master cylinder was not releasing pressure via its internal spring.

My setup was purchased from the aviation aisle at my local hardware store. Same "wheel collar" (that is from my RC days), and springs. I just have a large washer at the base of the spring.

Regards,
Jeff Orear
RV6A N782P
Hatz Classic, Welding fuselage
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rob
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Part numbers

Post by rob »

I found the parts list, so I figured I would kill two birds with one cluster of packets (the techies will get that one) --

These are the McMaster part numbers

6389K625 NYLON BEARING, FLANGED, FOR 3/8" SHAFT DIA, 1/2" OD, 3/8" LENGTH

9657K115 STEEL COMPRESSION SPRING, ZNC-PLTD SPRING-TEMPERED, 3" L, 1/2" OD, .047" DIA

9946K13 ALUMINUM SET SCREW SHAFT COLLAR, 3/8" BORE, 3/4" OUTSIDE DIAMETER, 3/8" WIDTH

Cheap insurance to help prevent a stuck pedal. I found these parts on the other board, and then got Chad and Terry W. to get in on this. With 3 of us together, it knocked the price down to around $5 a set.
Rob Johnson
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cjensen
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Post by cjensen »

Thanks Rob!!!

8) 8) 8)
Chad Jensen
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RV9inIowa
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Post by RV9inIowa »

This sounds great - anyone in for a repeat "group buy"? Sign me up! Smitty, you need some of these!
Dave G.
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JohnR
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Post by JohnR »

Dave,

I would go for some. If we could find another person or so close by we could save on shipping which I'm sure is the biggest cost.
JohnR
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weezbad
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Post by weezbad »

i would like some but i must admit i wonder about them scuffing the shaft and causing leakage over time. or is the shaft not sealed there and simply attached to a piston of larger diameter than the shaft and no need for more than a dust seal and not really a dynamic seal.
william....don't let it beat you down, you are stronger than you think.

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Brantel
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Post by Brantel »

weezbad wrote:i would like some but i must admit i wonder about them scuffing the shaft and causing leakage over time. or is the shaft not sealed there and simply attached to a piston of larger diameter than the shaft and no need for more than a dust seal and not really a dynamic seal.
I would be really easy to put a slight ravit on that plastic bushing to have it fit inside the first turn or too of the spring. That way the spring would never touch the sensitive area of the shaft.
Brantel (Brian Chesteen),
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JohnR
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Post by JohnR »

Brantel wrote:[I would be really easy to put a slight ravit on that plastic bushing to have it fit inside the first turn or too of the spring. That way the spring would never touch the sensitive area of the shaft.
Great idea! I'm going to file this one away for later use.
JohnR
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aparchment
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Nice

Post by aparchment »

Hey Chad:

Thanks for that idea. I will add that to my brake pedals (just finished last weekend).

I was wondering why you used the anodized 90 degree aluminum fittings for the hose to cylinder connections rather than the brass. Is it because you needed a flair connection with the braided hoses? Also, what lengths of hoses did you use and where did you get them? Bonaco Performance?

Antony

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cjensen
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Post by cjensen »

Hey Antony,

Not my idea...I just posted it. Rob Johnson came up with this one for us local guys...

Yep, the flared fittings are needed for the braided lines. They are from Bonaco, and they now have an "RV kit" put together. I pieced mine together before they made the kit, but it's available now. The lengths are two 36" and two 24" lines per side.

8)
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captain_john
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Post by captain_john »

Nice!

I am gonna order up some springs and brake lines soon! I wanna put this stuff and the parking brake to bed soon!

Thanks guys!

;) CJ
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JohnR
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Post by JohnR »

So are the braided brake lines really needed? Most of the RV's I've been in I thought just had the standard Van's issue plastic, I need to look closer I guess. I don't want to have problems with brake lines and if the stock ones are causing issues I'll order up a set. On the other hand if they are okay I can might as well use them. Thoughts?
JohnR
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smithhb
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Post by smithhb »

John,

I bought the braided lines from Bonaco about three months ago after watching two fellow RV owners fight to stop brake line leaks in the Vans' stock Parker-Hannifin brake lines and brass fittings. It appears to be pretty common for the lines to leak fluid at the fittings after a few hours of use.

If you don't mind brake fluid on your carpet or spending hours on your back under the panel trying to fix the leaks, use the stock lines and fittings.

Just my 2 cents.
Bret Smith
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painless
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Post by painless »

John:

I have the standard Van's issued brake lines in my 6A. Not a drop of brake fluid. I did , however, replace the fittings supplied by Van's for the plastic reservoir lines. Mine were plastic ones like what is connected to the reservoir. I used nice brass ones a friend got me at each brake cylinder, and they work great.

You really don't need the return lines from the resevoir to be braided, as these are not pressurized.
Jeff Orear
RV6A N782P
Hatz Classic, Welding fuselage
Hatz build log. https://eaabuilderslog.org/?blproject&p ... GNCwv&sid=
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captain_john
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Post by captain_john »

Yah, I get that. People either love the plastic ones or hate 'em!

Me? I would rather look at stainless steel ones daily.

They are prolly not needed... but hey, it is why we build our own designs.

:wink: CJ
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aparchment
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price?

Post by aparchment »

Thanks for the info Chad.

How much did you guys pay for the Bonaco parts?

Antony

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cjensen
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Post by cjensen »

Not sure what the current "kit" cost is, but when I ordered mine, they were about $60 shipped.
Chad Jensen
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aparchment
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more brake spring questions

Post by aparchment »

So guys:

I installed the springs etc. on the cylinders, and I notice that they interfere with the full length of travel of the cylinder. I don't know yet how much travel is needed, but this left me a little concerned.

Also, my brake pedals are really stiff once all of the bolts are torqued to their proper values. It would seem that they should be a little easier to pivot. The rudder pedal motion is nice and smooth, but not the brakes. What have others done?

Antony

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cjensen
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Post by cjensen »

Antony...are you using the proper castle nuts for the brake pedal pivot? Those don't get torque'd at all. In fact, I installed mine REALLY loose to make sure I never have a stuck pedal. The springs are overkill if you leave the nuts nice and loose, but I chose both as a "belt and suspenders" approach.

The castle nuts with the cotter pin will never move as long as the pin is in place, no torque needed.
Chad Jensen
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