Results 1 to 20 of 20

Thread: Need help with bleeding Steveís brakes

  1. #1

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like

    Need help with bleeding Steveís brakes

    Pa-18 on 35s with Steveís brakes.

    200í landings and keeping the tail up with the brakes was not an issue. Left calipers on and went to skis and never cracked a brake line. Went back to wheels and brakes are solid but stopping is inconsistent. I canít keep the tail up with the brakes. The brakes wonít lock up a tire on taxi when I used to be able to do that easily. Also brakes make a moaning/squealing sound similar to being wet but they do this consistently.

    Iíve bled the brakes accordingly to Steveís direction. Iíve open the bleed screw on the caliper and drained all fluid that I could out of the caliper and started over, filling from the bottom. I know there is something going on and I canít figure it out. Pads in good shape and calipers worked fine prior to going to skis.

    Iím guessing there is air somewhere may try lifting to tail to bleed. Also not sure how to get all brake fluid out of the master cylinder. On 35 it rides nose high so I canít get it all out.

    Any help?

    Thanks

  2. #2
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    579
    Post Thanks / Like
    How is the pedal feel? Is it firm but you just don't have stopping power or is the pedal mushy and using a lot of pedal travel to get any braking?

    Might not be a bleed issue, might have contaminated brake pads if the pedal is fairly firm.

  3. #3

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    Quote Originally Posted by Crash, Jr. View Post
    How is the pedal feel? Is it firm but you just don't have stopping power or is the pedal mushy and using a lot of pedal travel to get any braking?

    Might not be a bleed issue, might have contaminated brake pads if the pedal is fairly firm.

    Pedal is hard and not much travel but no stopping power. If contained pad or rotor whatís the remedy to fix?

  4. #4

    Join Date
    Feb 2015
    Location
    Anchorage
    Posts
    90
    Post Thanks / Like
    Clean them up with brake clean.
    Likes adamgrenda liked this post

  5. #5
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    11,165
    Post Thanks / Like
    It sounds as though the large pins which hold the brake housing to the adapter may be sticking. When this happens the housing doesn't move preventing both brake pads from clamping the disc. No amount of bleeding solves this issue.
    N1PA

  6. #6
    supercrow's Avatar
    Join Date
    Dec 2008
    Location
    Smith Pond near Millinocket, Me
    Posts
    501
    Post Thanks / Like
    Quote Originally Posted by skywagon8a View Post
    It sounds as though the large pins which hold the brake housing to the adapter may be sticking. When this happens the housing doesn't move preventing both brake pads from clamping the disc. No amount of bleeding solves this issue.
    Yup. Especially after being on skis this winter if not relubed.

  7. #7
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,847
    Post Thanks / Like
    Take the calipers off with brakes lines still attached and clean the pins on the caliper and the bushings in the torque plates and lubricate with silicone spray. It will allow the caliper to float but will not attract dirt and dust.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers
    Likes DENNY liked this post

  8. #8

    Join Date
    Sep 2003
    Posts
    7,446
    Post Thanks / Like
    Or graphite powder.
    Once in a while you can get the pins too slippery and set up a chatter.

  9. #9

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    I’ve cleaned and checked and lubed the pins when I put the wheels back on. I’ll pull the caliper off and clean the pads and rotors w brake clean and check the pins again.
    Thanks Brmoore thanked for this post

  10. #10
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    579
    Post Thanks / Like
    On the pads I use 400 grit to expose fresh surface and then brake clean them since you very possibly have a glazed layer on the pads. The disc you can get away with just brake clean on a rag to clean off any contamination but it's not a bad idea to scotch brite them if they have some rust from sitting.

  11. #11

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    Quote Originally Posted by Crash, Jr. View Post
    On the pads I use 400 grit to expose fresh surface and then brake clean them since you very possibly have a glazed layer on the pads. The disc you can get away with just brake clean on a rag to clean off any contamination but it's not a bad idea to scotch brite them if they have some rust from sitting.

    yup Iíll try all that today too. What is the usual culprit of a contaminated pad? I donít remember getting those dirty but between grease and swapping skis and wheels it very easily could of got some junk in there to foul things up.
    Thanks Brmoore thanked for this post

  12. #12
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    579
    Post Thanks / Like
    It's usually brake fluid from leaking brake pucks but since you didn't remove your brakes when you went on skis it could simply be some crud in the snow that got on the brakes. Could have just been taxiing through some slushy snow at the airport that had some oil on it or something and got it on the brakes. Oil and gas float on top of water so during breakup a lot of crap that's on the pavement under the snow pack can float to the top when it gets slushy.

    Best thing to do is remove your calipers when you go on skis and cap the lines to prevent pad contamination or even worse corrosion in your brake calipers.

  13. #13

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    Quote Originally Posted by Crash, Jr. View Post
    It's usually brake fluid from leaking brake pucks but since you didn't remove your brakes when you went on skis it could simply be some crud in the snow that got on the brakes. Could have just been taxiing through some slushy snow at the airport that had some oil on it or something and got it on the brakes. Oil and gas float on top of water so during breakup a lot of crap that's on the pavement under the snow pack can float to the top when it gets slushy.

    Best thing to do is remove your calipers when you go on skis and cap the lines to prevent pad contamination or even worse corrosion in your brake calipers.

    Yup makes sense. I tried that with my NR and worked well. I had a hard time getting every last air bubble out of the Steveís brakes so I left them on this year. Iíll let you know how today turns out. Noted for future.

  14. #14
    Steve's Aircraft (Brian)'s Avatar
    Join Date
    Aug 2004
    Location
    White City, Oregon
    Posts
    951
    Post Thanks / Like
    Make sure you bleed all the air out of the top bleed port on the cylinders... the way our cylinders are designed it can trap air there fairly easy hence the reason we put the bleeders there... might take a few tries to get it all out... I usually pump up the cylinder by hand and then open that valve with a rag on top of it to force any trapped air out, kind of like bleeding car brakes... Also, if your brake lines are at the bottom of your calipers at the wheel and bleeders on the top make sure you do not have any trapped air there by the same method... all other tips for the caliper pins and pads mentioned need to be checked also..

    Brian


    Sent from my iPhone using Tapatalk
    Thanks WindOnHisNose thanked for this post

  15. #15

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    Thanks Brian. I’ve bled that way and got all air out. What is the best way to start over so to speak and get all fluid out? Open the bleeder on the bottom and had the kid pump the brakes but still couldn’t get all fluid out it seemed.

    despite all this pedal moves 1/8” and then gets rock hard and I can’t get more air out at the caliper (brake line on top) or out of the bleeder so I’m guessing it’s the pads.

  16. #16

    Join Date
    Jan 2017
    Location
    King Salmon, AK
    Posts
    90
    Post Thanks / Like
    Click image for larger version. 

Name:	4ACB9BAF-B814-4A78-9940-50623D93B45C.jpg 
Views:	53 
Size:	57.8 KB 
ID:	55407


    The pads had a slight glaze to them so I cleaned them with sandpaper and brake clean. Rotors look good cleaned it with scotchbrite and brake clean. The piston on the caliper had some grease gunk on them. Is this an indication of leaking o rings. I’ve never had any fluid leaks but have never inspected this part of the brake before this.

    had the wife use her feet to get more pressure and got a few small as in very small air pockets out of each brake. They are back to being solid now. Free floating in the pins and lubed there.

    I’ll keep an eye on the caliper for leaks. Any ideas?Click image for larger version. 

Name:	8D4554C8-DFC9-4D49-8FA6-338E4C15669A.jpg 
Views:	46 
Size:	68.1 KB 
ID:	55408
    Likes Crash, Jr. liked this post

  17. #17
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    20,847
    Post Thanks / Like
    I always look at the calipers for leaks at annual. If the o'rings leak there will be a sticky wet substance at the lowest point on the caliper. New o'rings usually fix the issue unless there is pitting in the cylinder bore of the caliper.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers
    Thanks adamgrenda thanked for this post
    Likes AkPA/18 liked this post

  18. #18
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    3,557
    Post Thanks / Like
    I had an experience of the brake o-rings leaking when the pads got kind of thin.
    The previous owner warned me of this, and told me to just buy new pads when it happened.
    I replaced them once, honed the caliper bores while I was at it.
    The next time around, I got the bright idea to measure the discs--bingo!
    They were below minimum thickness.
    I replaced the discs & now the o-rings don't ever leak.
    Another unexpected benefit is that the pads seem to last much longer with the nice new smooth discs.

    FWIW I do all my filling & bleeding from the caliper end with a little oiler can from Napa.
    Works great.
    Cessna Skywagon-- accept no substitute!
    Likes AkPA/18 liked this post

  19. #19
    Steve's Aircraft (Brian)'s Avatar
    Join Date
    Aug 2004
    Location
    White City, Oregon
    Posts
    951
    Post Thanks / Like
    Quote Originally Posted by adamgrenda View Post
    Click image for larger version. 

Name:	4ACB9BAF-B814-4A78-9940-50623D93B45C.jpg 
Views:	53 
Size:	57.8 KB 
ID:	55407


    The pads had a slight glaze to them so I cleaned them with sandpaper and brake clean. Rotors look good cleaned it with scotchbrite and brake clean. The piston on the caliper had some grease gunk on them. Is this an indication of leaking o rings. Iíve never had any fluid leaks but have never inspected this part of the brake before this.

    had the wife use her feet to get more pressure and got a few small as in very small air pockets out of each brake. They are back to being solid now. Free floating in the pins and lubed there.

    Iíll keep an eye on the caliper for leaks. Any ideas?Click image for larger version. 

Name:	8D4554C8-DFC9-4D49-8FA6-338E4C15669A.jpg 
Views:	46 
Size:	68.1 KB 
ID:	55408
    Based off that first picture alone I would take those apart and check the condition of the O-Rings and bore of the calipers. Clean them up real good, replace O-Rings, and then re-bleed the system.

    Brian.

  20. #20
    Crash, Jr.'s Avatar
    Join Date
    May 2015
    Location
    Anchorage, AK
    Posts
    579
    Post Thanks / Like
    I agree with Brian. Mind had that yellowish scum on them from brake fluid leaking before I rebuilt them. O-rings are cheap. MS28775-222 quantity 2 per caliper. Check the bores for scoring and sand pits/scratches out with 400 grit and final polish with grey scotch brite.

Similar Threads

  1. Filling and bleeding newly installed brakes?
    By supercub in forum Cafe Supercub
    Replies: 18
    Last Post: 06-13-2020, 01:00 PM
  2. bleeding brakes
    By garyh in forum Cafe Supercub
    Replies: 16
    Last Post: 11-21-2013, 01:17 PM
  3. Bleeding (brakes) question
    By WindOnHisNose in forum Tips and Tricks
    Replies: 14
    Last Post: 03-20-2006, 09:19 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •