Leak in brakes

[crxcte]

I have a leak (drip of hydraulic fluid) in my Cleveland brakes on the main.  Anyone have a similar issue. 

[carusoam]

A photo might help...

[MHemperly]

^^ photo would help for sure. If I had to guess it's probably the o-ring on the cylinder inside the break caliper. Easy fix.

[crxcte]

The leak is just a drip at the bottom of the brake housing not from the line.  I was guessing oring.  I've read about the lining being replaced but sure for what cause.

[kerry]

I've had both of my calipers leaked.  I think I used a standard size o-ring from a parker o-ring kit that I matched up.  Like mentioned above it is a easy fix.

[jetdriven]

Easy fix. There are 3 big causes, the o-ring is old and worn out. Cheap fix. The brake pads are worn out and the caliper o-ring is riding near the end of the bore where all the brake dust is, new pads and a good cleaning and o-ring change will do it. And the most expensive is where the inner bore of the caliper gets pitted and it leaks through those. Light honing might get you by, or you may have to replace the caliper.

[N201MKTurbo]

The problem is the bore outside of the o ring gets corroded. As the linings wear the o ring moves into the corroded region and doesn't seal.

I usually take the caliper completely off. Put a plug on the brake line as soon as you remove the caliper and you can just forward bleed it after replacement. Clean the corrosion with 400 sand paper and then polish with 800. Then clean it real good including blowing the passages out with compressed air to get any grit out of the system. I then usually paint it just because I'm that way. Reassemble with a new o ring, bleed and go flying.

[DaV8or]

I have had them both leak. Both times I had LASAR put in new O rings at annual. It's hardly easy. The bleeding process is a serious bitch. The brake system on our planes is crappy because one shouldn't have to use a gallon of fluid, make a big mess, take two guys 30-40 minutes to hopefully (cross your fingers) get all the bubbles out and have both the left and right side feel the same. It's a job they don't like.

 

Oh, and the O ring fix doesn't last. One of mine is leaking again. Years ago, I learned on cars that rebuilding brake cylinders was a fool's errand. If you want the brakes to be reliable and not leak, replace the whole cylinder. I am coming to see that the same holds true in airplanes. I don't think I'm going to waste anymore money on O rings.

[kerry]

I like the brake system.  Its not difficult to bleed.  I would let the fluid drain out on just the one side that the caliper is leaking on.  Bleeding the brake can be a one man job.  A second man is helpful in telling you when the reservoir is full.  I use a small oiling can and some vinyl tubing and pump the brake fluid from the caliper up to the reservoir.

[kerry]

I don't think my whole system take more than 1/2 a quart. 

[jetdriven]

I second that bleeding comment. 3 years ago we left the caliper hose open for the caliper repair and left the hose open. The next morning we arrived to find a huge puddle of gummy red hydraulic fluid to clean up. Since then we have bled the brakes a dozen times, wasting several whole days in the shop, and it's still not right. I'm gonna try new seals in the parking brake valve and bleed both sides at once.

[N201MKTurbo]

If you can't get the brakes to be real firm, just go fly the plane for a while. Over time they will firm up. The bubbles seem to work themselves out over time. Pumping the brakes at high altitude seems to speed the process.

I'm not advocating flying the plane with unsafe brakes, but if they are a little spongy they will still stop the plane just fine.

Or you can pay your mechanic for many hours of his time to pump gallons of 5606 through the system.

[crxcte]

Well it sounded simple as first described but it appears it may not be such a quick fix, or may be it will only be temporary fix. Seems my o-rings were changed not to long ago.

 

Thank you for your inputs. I have done this before but I've slept a few times since then.

[N601RX]

The entire caliper assembly is around $700 if I remember correctly. You can buy a new body for $200 and put the parts out of your old ones in the new body and fix the pitting problems. I had severely pitted cylinders 2 years ago and did this. I have not had any problems since.

[jetdriven]

Ebay is a good source for these things. They come available from time to time. New costs are ridiculous.

[N201MKTurbo]

$200 for a new body or 5minuets with some sand paper.

Some mechanics don't know how to fix anything. Just replace parts...

[scottfromiowa]

The re-build seal kit for my master brake-cylinders didn't cost much and was such a wonderful transition from mushy so-so brakes that had trouble holding in run-up to a quality system...The refurb on my flaps (shared system) further improved brake quality and just overall satisfaction in flying a vintage plane that functions as it should. Anybody fly the original vs. Cleveland brakes? Mine had the later from whenI purchased so don't have a comparison on quality improvement. Totally agree with servicing vs. replacement on components as first plan to address braking woes. I replaced my exterior brake lines (in wheel-well) as they were also OEM and leaked at fittings.

[crxcte]

If you can't get the brakes to be real firm, just go fly the plane for a while. Over time they will firm up. The bubbles seem to work themselves out over time. Pumping the brakes at high altitude seems to speed the process.

I'm not advocating flying the plane with unsafe brakes, but if they are a little spongy they will still stop the plane just fine.

Or you can pay your mechanic for many hours of his time to pump gallons of 5606 through the system.

Thanks for your info, certainly the most economic choice.  

[IvoryM]

I had the exact same issue a couple months ago. It was an easy fix.

Aircraft spruce stocks the caliper o-ring (part # MS 28775-326). Drain the fluid pull the caliper off but no need to disconnect the brake line. Remove the pads. If the pads are bad i can give the part # for them too. Pull the piston out of the caliper. Remove the o-ring from the piston clean it with break parts cleaner and install the new o-ring. Clean the caliper cylinder and sand with fine sand paper if needed. The cylinder bore is shallow so it's hard to use a hone. Lubricate with fluid and push the Piston back into the cylinder with a c clamp and reassemble. Now bleeding the breaks is easy. A guy named Steve explained it to me on this site and it worked great. Get a old style metal manual pump oil can. Like the tin man on the wizard of oz used. Get a small clear hose that you can put over the nozzle on the oil can and the bleeder on the caliper. Remove the cap on the brake resivor. Then fill the can with the correct brake fluid and pump the fluid in from the bottom up. It's work perfect and I didn't even have to bleed the brakes after. I was done in less than an hour and including new break linings i spent less than a $100 bucks. Of course you need a A&P to sign off. Good luck.

Mitch

[scottfromiowa]

If you can't get the brakes to be real firm, just go fly the plane for a while. Over time they will firm up. The bubbles seem to work themselves out over time. Pumping the brakes at high altitude seems to speed the process.

I'm not advocating flying the plane with unsafe brakes, but if they are a little spongy they will still stop the plane just fine.

Or you can pay your mechanic for many hours of his time to pump gallons of 5606 through the system.

NOPE. Don't agree with this post at all. My plane had 50 year old seals in brakes and flaps. Now that they are changed I have great brakes. Was not expensive and having the systems work is worth it to me.

[N201MKTurbo]

Who said anything about not replacing seals and not having your brakes and flaps working right? You must have misunderstood me. I was only talking about bleeding the system. If you spend a half hour bleeding the system and the brakes are still a little spongy, they will firm up by themselves after a few flights.

[the_elkhartian]

Thread resurrection...

Am I having the same issue as above? I have the tiniest leak and it appears to be coming from the bleeder. In about a week I have about a one inch spot of brake fluid on the ground. 
 

I took a picture after wiping the little zerk. But before I did it had a tiny little sphere of 5606 hanging right off the tip. So I think it’s leaking from there. 

[carusoam]

WTW,  
 

Hard to say...

This thread is about spongy brakes, and all the rubber and metal things to be replaced or worked to improve that situation...

So... unless you have spongy brakes I would go with no... not what you are seeing...

But, the OP did have a leak... but not a drip from the bleeder valve...

Look up how brake bleeder valves work...

Might need tightening...

Might need replacement...

Might cost $10...

$15 if you need to buy a wrench...

 

Being the lowest point of the assembly... gravity may be making it look like the valve is leaking...

Is it coming from anywhere else?  Do you have firm or spongy brakes?

Something like this... https://www.aircraftspruce.com/catalog/lgpages/brake_bledders1.php?gclid=CjwKCAjwmrn5BRB2EiwAZgL9otAvwA1jmsSdsmhXBT0ZOSV8Epj35vLTBgZ3eRIQ4PCY_Njlo2Dn8BoCSxUQAvD_BwE

PP thoughts only, not a mechanic...

Best regards,

-a-

[the_elkhartian]

Agree on the lowest point theory. I’ll watch it and verify where it’s leaking from now that I cleaned it up a little. 
 

As far as mushy it’s hard to say. They are definitely softer than the 2020 Archer I flew earlier this week. But they’re about the same as they’ve been since I’ve owned the airplane. 
 

Previous owner had the flap pump overhauled at annual in May. (Lasar did the overhaul, local shop did the install) so I have no confidence as to whether they bled the system properly or what my brakes “should” feel like. 

[carusoam]

If you can flat spot the tires after landing... that is a good sign your brakes are working...

If you apply full brakes with no fear of having to buy new tires... a subtle hint that there may be a performance improvement available...

Best regards,

-a-