Bleeding Surge Brakes

[woody619]

Hi,
I've read the posts, but I'm missing something or somethings wrong. I have Drum Surge Brakes. I tried, but couldn't get the brake fluid to flow.

I'm using the chain and 2x4 to compress it. I tried a couple different ways. What am I missing?

I filled it up 3/4 the way full. I didn't close the lid. Should I?
I started pumping, but then it didn't flow. No bubbles. I could tell because the fluid level never got lower.
Then we opened up the bleeder valve on the furthest wheel cylinder.
Then started compressing the actuator again, but the fluid isn't flowing. No bubbles. I'm paying close attention to the fluid level.

What could be wrong?

Thanks!

[erie_guy]

I would guess the master cylinder is in need of a rebuilding/replacement. You might disconnect the hydraulic line at the master cylinder and see if you can get the fluid to pump out there. How old is the trailer ? That might be a clue to its condition. Many trailer owners do not routinely inspect the braking system on their equipment and are inviting problems.

erie_guy
Port Clinton, OH

[bruceb58]

Disconnect the brake line from the rear of the master cylinder and try it. If no fluid flows, then your master cylinder is bad.

Just out of curiosity, why are you bleeding your brakes? Did you change something or was the master cylinder dry? If the master cylinder was dry you could have a variety of problems you need to fix before bothering with bleeding.

[woody619]

The actuator is new. It's the first time it's had fluid in it. I just put new brake lines, hubs drums, wheel cylinders, bearings and all. it all looks good. I did reset that emergency brake yesterday. Could I have not put it together correctly? It didn't seem that hard. I'll take off the brake line to the master cylinfer and try that. I'll keep you guys posted. Thanks

[speedwrench]

Should have bench bled MC before installing, but no biggie.
Put a bleeder line on the MC that will recirculate the fluid, bleed MC, then hook up to wheels and bleed them. Or fill MC, jack trailer front up high and leave set overnight, then bleed wheels. Works sometimes.

DAve

[woody619]

You guys were right. No fluid even coming out of the brake cylinder. I poked strand of wire brush through the valve and cleared it out. Good to go. Thanks guys!

[bruceb58]

Why did you need to poke anything on a brand new master cylinder? Hope you didn't puncture the residual valve.

[woody619]

I sure hope I didn't poke anything out I wasn't supposed to. The valve I that I did poke, was the brass one the comes out of the master cylinder that connects to the brake line. Am I fine? It really looked just like all brass fitting. We tried blowing out of it and couldn't. I thought a grain of sand or metal shaving might have fell in there. It's a real small hole.

[bruceb58]

I thought this was a brand new master cylinder. How far did you poke in there?

[woody619]

Not far into the master cylinder (but it is new), but what we did was take off (unscrewed) the brass valve that goes to the brake line from the master cylinder. Then looked to see if it was clogged, then blew on it, but couldn't. So we then used a strand of the wire brush and poked it through the small hole in the brass valve. As soon as we did that. We screwed it back on and fluid started coming out of it slowly, which it wasn't doing before. I haven't tested the brakes (road), but we know there's fluid in the lines. Is the residual valve a part of the master cylinder or apart of that brass valve that connects the master cylinder and the brake line? Thanks! Hope we didn't mess anything up.

[bruceb58]

OK...that sounds good. The residual valve is in the master cylinder. Weird that you would get something blocking that brass piece on a brand new part.

[woody619]

Thanks! I was worried for a sec

[Eric 3.7LX Alpha 1]

You could also try using something like this tool from Harbor Freight. A vacuum break bleeding kit. It attaches to the bleeder on the wheel cylinder and pulls a vac. thru the lines. Cheap money too-

http://www.harborfreight.com/brake-b...kit-92474.html

[truline]

I am having the same issue, replaced all the brake assemblies, lines, & master cylinder. Trying to bleed brakes for the past three days and only getting some fluid and lots of air with vacuum bleeders (I am using two different ones, one is a MityVac hand bleeder and one is a Harbor Freight pneumatic bleeder). I am wondering if I have that much air in the system since it is basically new, or if there is any tips someone can offer to move the process along in a more timely manner.

[bruceb58]

Depending on the bleed nipples, using the vacuum bleeders can be hit or miss because it is so easy to get at air leak at the threads when you loosen the bleeder. You may have to go the old fasion way and have some one operate the master cylinder while having a tube on the bleed nipple into a bottle.

Before you give up completely, take the bleeder out and put some teflon tape on the bleeder threads and screw it back in and try it.

[truline]

I am done! I ended up doing it the old fashioned way though it helps to have a forklift. Still was a pain in the *** backing and pushing and hopefully not over pushing the MC! I left the trailer overnight elevated with the furthest bleed screw opeen and this morning when I checked it there was more fluid in the tube. Tried the vacuum bleeder again and no joy so I put a ball on the forklift and went ahead with the old fashioned way. I did find a problem though at the T where the first axle branches off to the second, there was a leak. something that only would appear with the force and presure coming from actually manipulating the MC. The vacuum bleeders I have are just not strong enough to do that.