Rv7. I know I’m going to end up doing all 4. The question is where do I find the appropriate illustrated parts catalog?
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One of the brake pedals is stuck down. Will not come up.
- Thread starter rockyfatcat
- Start date
Rv7. I know I’m going to end up doing all 4. The question is where do I find the appropriate illustrated parts catalog?
Have you figured out why it's sticking -- Master Cylinder failed, pivot bolt/nuts too tight, etc.?
If you think it's the master cylinder, check out MATCO's website -- example: https://matcoals.com/wp-content/uploads/2023/02/3D-MC-4FL.pdf
If you think it's the master cylinder, check out MATCO's website -- example: https://matcoals.com/wp-content/uploads/2023/02/3D-MC-4FL.pdf
I think it was working when I bought the airplane and did the pre-buy. It has 61 hours on it and was not flyable when I purchased it.
I rebuilt the calipers thinking there was a leak on the right side. I subsequently learned the brake line was leaking at the swedge and replaced the entire line.
I recently put the pilot seat back it to test the height of the control stick and clearance to the new panel with the new stick grip and had my feet on the pedals for the first time since I purchased it.
I’m just fixing all the squawks now.
Is this a Matco brake? I do not have any markings on any of the 4 units
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Yes - it's a Matco "primary" (nee Master) cylinder.
Manually pull the pedal back to see if its mechanical binding, or hydraulic (piston/seal) binding.
IF it is in fact the master cylinder stuck , the return springs mentioned above might do the trick. On looking at your original post pic again. It looks to me that the rudder and/or tailwheel position is holding the pedals in a different position from "neutral" Which is entirely acceptable especially on a tailwheel plane. Maybe just my 77 year old eyes!!! A little right foot may correct your problem.
The wings have been off for almost a year. This has been rolled back and forth to the avionics shop a couple of times. The rudder pedals are what they are from pushing it into my corner of the hangar.
I appreciate all the info. I will be calling Matco about some parts tomorrow.
RV6_OKLA
Well Known Member
If the pedal is stuck in the down position and you can't pull it back up, then there is a problem inside the brake master cylinder. Matco, at the site mentioned above by bjdecker, has rebuild kits. If the pedal moves freely but stays in the down position and there is no signs of leaks, you just need to bleed the brakes and check the fluid level in the brake fluid reservoir.
As for the other cylinders, if they are working and there are no leaks where the piston rod moves in and out of the cylinder, they don't need repair.
As for the other cylinders, if they are working and there are no leaks where the piston rod moves in and out of the cylinder, they don't need repair.
are you sure it is stuck down? the pedals are not supposed to be in the same orientation relative to the bars. measure the exposed rod length to confirm. tough to tell from a pic, but they look the same.
What brake fluid did you put in? Wrong type could seize the system.
Agreed. This install needs a complete work over.
However, this is per plans and there are thousands of us flying this set up for tens of thousands of hours with no problems. I’m have over 900 hours on mine. Never a leak, fuss, or mus….
Tom makes great products and I would absolutely use his kit if I was to start over just out of convenience, but there is nothing wrong with the stock set up when done properly.
More concerning, the black “goop” around the fittings. Looks like a poor effort to conceal leaks.
Take this all apart and start over, as stock, or with Toms kit, whatever your pleasure.
Secondarily, many folks answer to brake pedal sticking is springs. You won’t need them if you use the single bottom bolt and align things correctly. When I see springs, I see a problem that was never resolved, just covered up.
Hard to tell for sure, but from looking at the left pedal it seems like this installation might already have a single pivot bolt there:
I bought some Royco 782 after looking at my Vans -7 thumbdrive.
I also called Matco and the MCMC-4F(L) (R) is the brake for most RV’s. I ordered a couple of the MC-4 REBUILD KITs.
Looks like it. It by itself isn’t a total fix though. You still have to insure there isn’t any binding in the system and correct that. As discussed before, it’s a poor design from the start and regardless will side load the piston and eventually the seal will leak.
