I have an '05 M trailer with Disc Brakes. I had a leaky connection on the hydralics and got air in the lines. The leak was where the fluid line connects to the master cylinder - got it tightened and it's not leaking any more.
I raised one wheel with a jack and actuating the brake (with screwdriver on actuator) did not even slow down a spinning wheel.
So I bled the brakes using the 2-person method with tube into a glass jar with some fluid in it to keep air out of the tube. Got a ton of air out of the system and fluid is coming out clear - but I'm not sure all is well.
Actuating the brakes with screwdriver now does stop the wheel but even when fully engaged I am able to [barely] turn the wheel by hand against the braking force. Should this be possible?
Is there some other adjustment or do you think I still have air in a line? Do these brakes fully lock up?
Bleeding M Trailer Brakes
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Paul S
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I would bleed again, just to make sure. Maybe take the trailer for a ride. I am sure the surge action offers more effort than using the screwdriver (I think anyway).
When I changed the brakes last year, first few uses, the brakes were less than optimal. Now they are great.
I am going to assume you have no other leaks in the system. Could be a internal leak in the Master cyl as well
When I changed the brakes last year, first few uses, the brakes were less than optimal. Now they are great.
I am going to assume you have no other leaks in the system. Could be a internal leak in the Master cyl as well
trailer at a 5:1 mechanical advantage makes it a 500 pound of braking force. Now you have to calc the braking force on a boat plus trailer - cant do this until my 1pm conf call...-
Paul S
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Also, if the brakes have not worked for a while, the brake pads might be frozen into the caliper, and not able to move. I ran into this when i did the brake job on my 04M trailer.
If the action does not improve.. might be time to remove the wheels and do a closer inspection (remove calipers, check/replace pads,etc)
Paul
If the action does not improve.. might be time to remove the wheels and do a closer inspection (remove calipers, check/replace pads,etc)
Paul
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nemo
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Thanks for the comments.
More information.. Last week I took the trailer to Les Schwabb to repack wheel bearings and bleed the brakes. They said bearings looked great and repacked them anyway. But they don't bleed brakes on trailers (liability) so didn't touch them. They did look at the brakes and said they look brand new (confirming they have not been working).
I use the boat only in fresh water and I park the boat and trailer (of course) in a big garage, so it's never left outside except for the few overnighters we've done.
Perhaps you are all right that I can't get enough force on the actuator with a screwdriver so maybe I'm okay.
I guess one test could be if I hook up to the vehicle and try to back it up with the electricals disconnected, so that I don't override the braking. It should be hard/impossible to back up, right?
More information.. Last week I took the trailer to Les Schwabb to repack wheel bearings and bleed the brakes. They said bearings looked great and repacked them anyway. But they don't bleed brakes on trailers (liability) so didn't touch them. They did look at the brakes and said they look brand new (confirming they have not been working).
I use the boat only in fresh water and I park the boat and trailer (of course) in a big garage, so it's never left outside except for the few overnighters we've done.
Perhaps you are all right that I can't get enough force on the actuator with a screwdriver so maybe I'm okay.
I guess one test could be if I hook up to the vehicle and try to back it up with the electricals disconnected, so that I don't override the braking. It should be hard/impossible to back up, right?
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Frank C
Absolutely!nemo wrote: . . . I guess one test could be if I hook up to the vehicle and try to back it up with the electricals disconnected, so that I don't override the braking. It should be hard/impossible to back up, right?
I've done precisely that (inadvertantly) and the trailer will not budge in reverse.
Yeah, well...I did that with my Excursion and let me tell you that it was far from impossible... But, I did notice some neat furrows in the gravel...Frank C wrote:Absolutely!nemo wrote: . . . I guess one test could be if I hook up to the vehicle and try to back it up with the electricals disconnected, so that I don't override the braking. It should be hard/impossible to back up, right?
I've done precisely that (inadvertantly) and the trailer will not budge in reverse.
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nemo
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Well, I just couldn't wait so hooked up the trailer to our Suburban and gave it the test. I pulled forward about 20 feet (all on concrete) and put her in reverse. I was able to power it backward but it definitely felt like the emergency brake was on (I checked and it wasn't 
) and it required a fairly heavy foot on the gas.
So should I be able to move it at all in reverse? DLT said they were on "gravel" - I presume I would have skidded on gravel.
Now, that said, I do have a problem. I went back to check on things and see I still have a fluid leak at the rear of the master cylinder where the line goes in. I'm afraid to tighten it further as it feels real tight already.
How do I seal the brake line joint to master cylinder?
Now I'm feeling under the gun a bit as I'm taking a bunch of older scouts out in the boat as 1 day of their week long high adventure 2 weeks from now. It's a 4 hour drive from here over mountains.. Not feeling good about this..
) and it required a fairly heavy foot on the gas.So should I be able to move it at all in reverse? DLT said they were on "gravel" - I presume I would have skidded on gravel.
Now, that said, I do have a problem. I went back to check on things and see I still have a fluid leak at the rear of the master cylinder where the line goes in. I'm afraid to tighten it further as it feels real tight already.
How do I seal the brake line joint to master cylinder?
Now I'm feeling under the gun a bit as I'm taking a bunch of older scouts out in the boat as 1 day of their week long high adventure 2 weeks from now. It's a 4 hour drive from here over mountains.. Not feeling good about this..
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baldbaby2000
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How does one test surge brakes? We brought our boat from Lake Granby down the mountain going through Berthod Pass, a drop of several thousand feet. When we got to the bottom the rear brake drums on our Surburban were way too hot to touch and the discs on the trailer brakes were barely warm. Backing up with the trailer lights disconnected seems to engage the brakes so I assume they're doing something.
Daniel
Daniel
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nemo
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I notice that another line coming out the side of the master cylinder has some kind of a red compound on the fitting threads. The line that's leaking is bare. I thought that these fittings were supposed to be bare, but one is not so perhaps there is some compound that's made for this.
I guess I need to google some more to find out what it it. Sure wouldn't want any gunk in my brake line..
I guess I need to google some more to find out what it it. Sure wouldn't want any gunk in my brake line..
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Paul S
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brake lines seal on the flare, not the threads, so adding goop won't do it.
get a flare wrench and tighten it a bit more. If not, unconnect it and inspect the fittings to see if they were misformed when it was built.
Not sure if the lines are steel or copper/nickle lines. Copper/nickle requires a bit of pressure to form a good seal sometimes.
You got to fix the leak in order to get good pressure at the wheels
Paul
get a flare wrench and tighten it a bit more. If not, unconnect it and inspect the fittings to see if they were misformed when it was built.
Not sure if the lines are steel or copper/nickle lines. Copper/nickle requires a bit of pressure to form a good seal sometimes.
You got to fix the leak in order to get good pressure at the wheels
Paul
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nemo
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I disconnected the fitting for inspection - It's actually the fitting into the back of the solenoid valve, not the back of the master cylinder (as I had stated).
The flare on end of the tube looks okay, but inside the solenoid valve, the place where this flare would seat, looks malformed. I need to find a magnifying glass tomorrow for a better look. I think I need to replace the solenoid valve to fix this - bummer.. Only other thing I can think of is if there is a way to put a gasket in there, but this feels bogus.
The flare on end of the tube looks okay, but inside the solenoid valve, the place where this flare would seat, looks malformed. I need to find a magnifying glass tomorrow for a better look. I think I need to replace the solenoid valve to fix this - bummer.. Only other thing I can think of is if there is a way to put a gasket in there, but this feels bogus.