VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.






VAF on Twitter:
@VansAirForceNet

  #1  
Old 11-30-2022, 12:43 PM
subpar_bucker subpar_bucker is offline
 
Join Date: Oct 2016
Location: Cranberry Twp, PA
Posts: 73
Default Newly sprung brake cylinder leak

I'm working through the PAP and after performing the brake testing I noticed a leak inside the plane on the pilot's side. The brakes have been assembled and tested prior. In fact the fuselage had been sitting in my garage for at least 2 years and no leaks. I moved to a hangar about 6 weeks ago (mentioning this because maybe colder temperatures might be a factor). The leak is happening just as the airplane is sitting in the hangar. Yesterday I was able to get a picture showing the leak at the top of the cylinder:

https://photos.app.goo.gl/yfZ6bYnGNz9PSvYt6

Matco's FAQ mentions this leak specifically:

"Question:
Why does my MC-5 master cylinder is leak around the top?

Answer:
Overfilling is the primary reason for leaking around the shaft. Since the master cylinder vents around the shaft, the fluid level should be only 3/4 full to allow for master cylinder travel with the rudder pedals. The MATCO master cylinder is designed to function within fifteen degrees of vertical. If you cannot install within fifteen degrees of vertical, use a remote reservoir master cylinder."

But I'm pretty sure none of those apply to my situation. There are some old VAF posts about leaks springing up here after 100's or 1000's of hours of use, but these brakes are brand new (maybe 100 cycles of testing on them tops).

Has anyone else had a similar issue? I'm wondering if there's a defect with the brake, or if the rebuild kit would fix this issue.
Reply With Quote
  #2  
Old 11-30-2022, 01:46 PM
gasman gasman is offline
 
Join Date: Mar 2007
Location: Sonoma County
Posts: 4,776
Default

It does not vent around that shaft. The seal is bad and needs to be replaced.
__________________
VAF #897 Warren Moretti
2022 =VAF= Dues PAID
Reply With Quote
  #3  
Old 11-30-2022, 04:11 PM
D Weisgerber's Avatar
D Weisgerber D Weisgerber is offline
 
Join Date: Sep 2019
Location: Ionia Michigan
Posts: 403
Default

Gasman is correct, you're brakes are remote reservoir cylinders.
__________________
Dave Weisgerber
RV8 N848DW. Ser#83830 done.
James Cowl
DAR inspection on 7-23-2021
First flight on 7-25-2021
Phase 2 on 9-3-2021
Reply With Quote
  #4  
Old 11-30-2022, 04:40 PM
PaulvS's Avatar
PaulvS PaulvS is offline
 
Join Date: Aug 2019
Location: Western Australia
Posts: 1,326
Default

A repair kit is available from Vans or elsewhere:
https://store.vansaircraft.com/matco...d4-repair.html
__________________
Paul vS (yes I'm also a Van)
Building RV-6A #22320 O-320 FP. Wings and tail complete, fuselage almost done, working on canopy.
Flying my Aeroprakt A-22 STOL and the aero club's RV-9A while I build
Reply With Quote
  #5  
Old 11-30-2022, 06:45 PM
subpar_bucker subpar_bucker is offline
 
Join Date: Oct 2016
Location: Cranberry Twp, PA
Posts: 73
Default

Thanks for the responses! I've already ordered the repair kit.
Reply With Quote
  #6  
Old 11-30-2022, 09:24 PM
N115SB N115SB is offline
 
Join Date: Mar 2013
Location: Morrilton, AR
Posts: 35
Default

When you install the repair kit, double check to make sure the internal snap ring is securely in the groove when on reassembly. Donít ask how I learned this.
__________________
Sheril Helton
Built-Glasair, GlaStar, Rotorway,
2-RV7A's, RV8A, RV10. Built and flying
150hp RV9A.
Reply With Quote
  #7  
Old 12-01-2022, 01:17 AM
avrojockey's Avatar
avrojockey avrojockey is offline
 
Join Date: Aug 2019
Location: Appleton, WI
Posts: 557
Default

Quote:
Originally Posted by subpar_bucker View Post
Thanks for the responses! I've already ordered the repair kit.
While you're at it...you need to bleed brakes, so accomplishing SL-00047 at the same time and replacing fluid may be in order if not done so already
__________________
Tim Holmes
Appleton, WI
RV-9A N904DC
2023 Dues Paid
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:52 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.