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Brake System RV-6

fbrewer

Well Known Member
I am trying to understand the brake system in my RV6

Here are the left side brakes:

cYKDSe


The lower black hoses come from the firewall. The upper black hoses are routed to the right side brakes in the lower position.

Here are the right side brakes:

hrxYSe


The lower black hoses come from the left brakes.

The upper plastic hoses go to the firewall.

I have good pressure on the left brakes, and they work properly.

The right brakes have no pressure at all. The pedals will move to to full extension and I am not able to pump up the brakes on the right side?

I can see small drips in the plastic line fittings.

Here is a picture of what I think is the in-source of hydraulics for the left brakes. This is on the lower firewall behind the left brake pedals.

kvca7e


Here is a picture of the out-flow of hydraulics coming from the right pedals.

fBMDtK


Are the gold metal blocks that have hydraulic hoses coming in and out, the master cylinder for the respective brake?

How am I able to have brake pressure and working brakes on the left, but no pressure and no working brakes on the right?

Are these brake systems completely independent of one another, but share a common hydraulic reservoir?

TIA

Frank
 
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OK, for some reason my photos did not attach to the previous posting.

I used the image button on the tool bar to add photos, but hmmm none were added.

I've hosted the images at imgbb.com

I have the proper opening and closing image tags with the image URL between. When I paste the image URL in a browser, I can see the image.

hmmm
 
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I am trying to understand the brake system in my RV6

Here are the left side brakes:

cYKDSe


The lower black hoses come from the firewall. The upper black hoses are routed to the right side brakes in the lower position.

Here are the right side brakes:

hrxYSe


The lower black hoses come from the left brakes.

The upper plastic hoses go to the firewall.

I have good pressure on the left brakes, and they work properly.

The right brakes have no pressure at all. The pedals will move to to full extension and I am not able to pump up the brakes on the right side?

I can see small drips in the plastic line fittings.

Here is a picture of what I think is the in-source of hydraulics for the left brakes. This is on the lower firewall behind the left brake pedals.

kvca7e


Here is a picture of the out-flow of hydraulics coming from the right pedals.

fBMDtK


Are the gold metal blocks that have hydraulic hoses coming in and out, the master cylinder for the respective brake?

How am I able to have brake pressure and working brakes on the left, but no pressure and no working brakes on the right?

Are these brake systems completely independent of one another, but share a common hydraulic reservoir?

TIA

Frank

When a brake master cyl is functioning properly, it is an open path for fluid from the low pressure/input side to the high pressure / output side when the pedal is in its free/unactivated state. In a single seat brake installation the upper ports are connected to the fluid reservoir and because it is an open path through the master cyl, the res. keeps the system supplied with fluid.
When a pedal is depressed even slightly, it closes the open path and begins to induce pressure on the outlet (bottom) port.

This also makes it possible for the pilots master cyl's to act as pass throughs for the passenger side cyl'ers to activate the brakes. The passenger side cyl'ers act as pass throughs for the reservoir to feed fluid to the system via the top fittings on that side.

You likely have air in the system somewhere between the passenger cyl's and the pilot side cyl's, or the system is just very low on fluid (can you see fluid in the lines going into the top of the passenger side cyl's?
 
Scott,

I can see air in the top line on the right seat rudder pedals.

I assume the right brake system needs to be bled to remove the air.

I don't understand why the left pedals work (pilot side) and the right pedals don't work (passenger side).

Since the right brakes are not working (passenger side), am I at risk for losing the left side brakes (pilot side)?
 
Scott,

I can see air in the top line on the right seat rudder pedals.

I assume the right brake system needs to be bled to remove the air.

I don't understand why the left pedals work (pilot side) and the right pedals don't work (passenger side).

Since the right brakes are not working (passenger side), am I at risk for losing the left side brakes (pilot side)?

Try pulling the two pilot brake pedals aft (toward the seat) and then try the co-pilot brakes again. On my 6, I found the internal springs were too weak to fully extend the master cylinder piston when the brakes were released. If they do not extend FULLY, you will be unable to use the co-pilot brakes. They usually stick a small fraction of an inch short, but that is all it takes to block the inlet port.

I ended up putting external springs on the master cylinder to ensure full extension

Larry
 
Try pulling the two pilot brake pedals aft (toward the seat) and then try the co-pilot brakes again. On my 6, I found the internal springs were too weak to fully extend the master cylinder piston when the brakes were released. If they do not extend FULLY, you will be unable to use the co-pilot brakes. They usually stick a small fraction of an inch short, but that is all it takes to block the inlet port.

I ended up putting external springs on the master cylinder to ensure full extension

Larry

The OP said the right side pedals will stroke to full extension.
If it was hung up pilot side cyl's they would be hard but have no brakes.
Chances are the system is low on fluid for some reason and the left side could be one stop away from not working as well.
 
Scott,

I can see air in the top line on the right seat rudder pedals.

I assume the right brake system needs to be bled to remove the air.

I don't understand why the left pedals work (pilot side) and the right pedals don't work (passenger side).

Since the right brakes are not working (passenger side), am I at risk for losing the left side brakes
(pilot side)?

Your left pedals still work because the lines from the left pedals to the brakes are100% full of fluid. You have air in your lines between your right pedals and your left pedals. When the air reaches your left pedals, they will also have excessive travel when pressed, and will fail if not fixed.
 
The OP said the right side pedals will stroke to full extension.
If it was hung up pilot side cyl's they would be hard but have no brakes.
Chances are the system is low on fluid for some reason and the left side could be one stop away from not working as well.

Thanks, I scanned the OP's first post too quickly.
 
Gasman,

Thanks for the explanation, I now get it.

I did think at some point the left brakes might fail, so it is time to get it fixed.
 
Members,

This morning my buddy and I bled the brakes on our RV-6. Thank you all for the detail.

We inserted a fitting in the reservoir that allowed us to put plastic tubing over the fitting to capture the hydraulic fluid overflow as we pressure fed from the calipers.

2 hours to set up. 5 minutes of work. Passenger brakes are now working and there is NO visible air in the line.

Easy peasy! Thanks
 
Members,

This morning my buddy and I bled the brakes on our RV-6. Thank you all for the detail.

We inserted a fitting in the reservoir that allowed us to put plastic tubing over the fitting to capture the hydraulic fluid overflow as we pressure fed from the calipers.

2 hours to set up. 5 minutes of work. Passenger brakes are now working and there is NO visible air in the line.

Easy peasy! Thanks

This is what I do. However, I take some fluid out of the reservoir as it can expand and run out making a bit of a mess when if is full up.
 
JonJay,

<< This is what I do. However, I take some fluid out of the reservoir as it can expand and run out making a bit of a mess when if is full up.>>

We solved that problem by taking the cap off the reservoir and then screwing in a fitting like this:

http://www.hydraulicsdirect.com/Pro...eo__VbAPiPDJqCtdYFDtoFennfhvX_mBoCieAQAvD_BwE

We then put an ID 1/2" plastic tube over the nipple of the fitting going into the reservoir.

Then when we pressure fed from the caliper, the excess hydraulic fluid ran down the plastic tub to a catch bottle that I zip tied to the wheel fairing bracket (so I wouldn't kick it over).

About a 2 hour set up (I new to doing this) and about 5 minutes to bleed both brakes.

Absolutely NO mess.
 
JonJay,

<< This is what I do. However, I take some fluid out of the reservoir as it can expand and run out making a bit of a mess when if is full up.>>

We solved that problem by taking the cap off the reservoir and then screwing in a fitting like this:

http://www.hydraulicsdirect.com/Pro...eo__VbAPiPDJqCtdYFDtoFennfhvX_mBoCieAQAvD_BwE

We then put an ID 1/2" plastic tube over the nipple of the fitting going into the reservoir.

Then when we pressure fed from the caliper, the excess hydraulic fluid ran down the plastic tub to a catch bottle that I zip tied to the wheel fairing bracket (so I wouldn't kick it over).

About a 2 hour set up (I new to doing this) and about 5 minutes to bleed both brakes.

Absolutely NO mess.

I think what Jon means is don't leave it 100% full when you are finished bleeding. I remove about a 1/2 inch of fluid for the same reason he mentioned.
 
Or your finger over the end of a straw from Mc Donald's. Or a syringe FREE at Wal Mart pharmacy.
 
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