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Brake fluid


mcrowley

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It's about time to fill my brake system. I understand the manual calls for a mineral oil based fluid. Does anyone know what the system capacity is so I know how much to order? Also, any great tips on techniques? Thanks all!

 

 

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It's about time to fill my brake system. I understand the manual calls for a mineral oil based fluid. Does anyone know what the system capacity is so I know how much to order? Also, any great tips on techniques? Thanks all!

I forgot to mention I have the dual brake option from ICP.

 

 

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The duel brake option is more confronting. (To those who like things correct.) Nev

Do you mean dual brakes confronting each other in a duel, or just leaving their options open?

rgmwa

 

 

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Being serious. Aren't most of the brake fluids used in this type of set up using mineral oil? If so the rubbers will be of a special type and there is much less corrosion than with the water absorbing conventional brake fluids out there. Another option is a silicone based fluid which again is only a good idea where the system is designed for it. Using the incorrect fluid can/will result in brake failure, at some stage. With most types installed for individual braking there is only a small reserve and I bleed them backwards. Lowest to highest point till it overflows. (Catch the excess of course, but there's not much of it if you are careful) Nev)

 

 

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The documentation that came with your brake kit should tell you what type of brake fluid to use. For example Matco say "red aircraft fluid Mil-H-5606 or other suitable petroleum or silicon-based fluids". I used Royco 782. One litre was plenty. Pump up slowly from the bottom using a one litre garden sprayer with some line connected to your bleed valve until the fluid eventually ends up in the reservoir. Do each brake in turn. Pumping from the bottom up reduces the chance of trapping air the system.

 

Nylex 1L Manual Garden Sprayer

 

rgmwa

 

 

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On a car, I've been emptying the master cylinder reservoir carefully by using a soap pump inner (bathroom style) and cleaning the bottom of the reservoir carefully and after adding new fluid you can easily tell when the new fluid comes through each bleed point. Some systems have some "uphill" sections where an air bubble may become trapped if you don't pressure bleed the system and move it through more quickly. Air in the system will cause a spongy feel and you can run out of pedal. If holding the brakes on lightly allows the pedal to slowly descend you have a leak somewhere usually the master cylinder internally. You might be able to pump them up but they are ready to fail completely. Nev

 

 

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The documentation that came with your brake kit should tell you what type of brake fluid to use. For example Matco say "red aircraft fluid Mil-H-5606 or other suitable petroleum or silicon-based fluids". I used Royco 782. One litre was plenty. Pump up slowly from the bottom using a one litre garden sprayer with some line connected to your bleed valve until the fluid eventually ends up in the reservoir. Do each brake in turn. Pumping from the bottom up reduces the chance of trapping air the system.Nylex 1L Manual Garden Sprayer

rgmwa

Have you seen the "documentation" that comes with a Savannah? ;-) The construction manual tells me to fill the brake system with a mineral base fluid but doesn't hint as to how, doesn't give a quantity, and doesn't give a specific type. So.... after some research I'm planning on using Royco 782 as it is more flame resistant (seems like a plus with brake lines and master cylinders surrounding my feet ;) I'm just not certain how much to order. I'm also going to try pushing it up from the calipers to the master cyclinders. I was hoping a Savannah builder would have a good idea about the capacity of the dual brake system.

 

 

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Have you seen the "documentation" that comes with a Savannah? ;-) The construction manual tells me to fill the brake system with a mineral base fluid but doesn't hint as to how, doesn't give a quantity, and doesn't give a specific type. So.... after some research I'm planning on using Royco 782 as it is more flame resistant (seems like a plus with brake lines and master cylinders surrounding my feet ;) I'm just not certain how much to order. I'm also going to try pushing it up from the calipers to the master cyclinders. I was hoping a Savannah builder would have a good idea about the capacity of the dual brake system.

My RV-12 has dual brakes too, so a litre (quart) should do the job. However we have plenty of Savvy owners here who should be able to confirm.

 

rgmwa

 

 

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Have you seen the "documentation" that comes with a Savannah? ;-) The construction manual tells me to fill the brake system with a mineral base fluid but doesn't hint as to how, doesn't give a quantity, and doesn't give a specific type. So.... after some research I'm planning on using Royco 782 as it is more flame resistant (seems like a plus with brake lines and master cylinders surrounding my feet ;) I'm just not certain how much to order. I'm also going to try pushing it up from the calipers to the master cyclinders. I was hoping a Savannah builder would have a good idea about the capacity of the dual brake system.

In my Pilot Operating Handbook P12&13/44, LANDING GEAR, my manual calls for:

 

Mineral Based Oil (Renofluid 3.000 IT, Fiat Tutela GI/A).

 

( DO NOT USE synthetic oil type DOT4)

 

It does not give a quantity.

 

Based on external measurements, I estimate:

 

Per Cylinder (at rudder pedal)= 28cc

 

Per Calliper = 12cc.

 

Hydraulic lines 5.2metres x 4mm = 65cc

 

So, for my single brake system, I would estimate 145cc (plus flushing, spillage etc)

 

If a dual system is just 2 more cylinders and a bit more line, I would estimate 225cc (plus etc),

 

assuming the components look like this:

 

DSCF1192.JPG.7350c8d9361bae9be0db7fa91da53da7.JPG

 

 

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The manual also says (in the section on assembling the brakes) to take out the breather screw in the top of the pedal cylinder, and fill from the calliper up (as described by rgmwa, above).

 

Well, actually, that's not what they say. But, y'know, it's what they're trying to mean...)

 

Which means coming up with some sort of pump (also as suggested by rgmwa).

 

I think when I get to this, I will get a couple of metres of neoprene tube and fit it to a fluid container, the other end to the calliper.

 

With the container on or near the ground, I will put fluid in the container.

 

Then gradually raise the container, which should cause fluid to go up the lines and into the pedal cylinder.

 

This may be more controllable than pumping the fluid in. However, I will need to make sure that all lines are 'uphill' for this to avoid airlocks.

 

Well, it's an idea....

 

Please let us know what works for you?

 

 

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Your Royco will work just fine, but so will any MIL-H-5606, although the flashpoint of the Royco synthetic is much higher, I'd be more worried about the flashpoint of your fuel than a few mls of hyd fluid. A 1qt can will be heaps, once open, you may want to store it in a better container as usually H-5606 is hygroscopic.

 

The Royco brand is double the price of Aeroshell, but double only means $13 a qt compared to $6 a qt.

 

 

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I used a big syringe and pumped it up from the bottom. Was not a drama...did it myself. I did borrow a bolt that Steve Donald made which basically had a hole drilled through it and a then screwed into the cyclinder and off this bolt was a plastic tube that then went into a bottle of fluid..this way no air got into the system

 

 

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The manual also says (in the section on assembling the brakes) to take out the breather screw in the top of the pedal cylinder, and fill from the calliper up (as described by rgmwa, above).Well, actually, that's not what they say. But, y'know, it's what they're trying to mean...)

Which means coming up with some sort of pump (also as suggested by rgmwa).

 

I think when I get to this, I will get a couple of metres of neoprene tube and fit it to a fluid container, the other end to the calliper.

 

With the container on or near the ground, I will put fluid in the container.

 

Then gradually raise the container, which should cause fluid to go up the lines and into the pedal cylinder.

 

This may be more controllable than pumping the fluid in. However, I will need to make sure that all lines are 'uphill' for this to avoid airlocks.

 

Well, it's an idea....

 

Please let us know what works for you?

Sounds Like a good idea to me!

 

 

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