Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

[E_Man]

Hi,

Thanks for looking. I just bought a two axle tandem trailer with a Surge Coupler (Titan/Dico Model 60) and Drum brakes. The previous owner advised that the brakes never worked since he got the trailer 3 years ago.

To bleed the brakes, I did the following:
* Topped up the Master Cylinder
* Actuated the coupler with a screwdriver until no more bubbling came out of the master cylinder
* Opened the right bleeder
* Actuated the coupler with a screwdriver until a stream of brake fluid was coming out with every actuation while keeping the master cylinder almost full.
* While keeping the coupler actuated fully, closed the bleeder.
* Did same for other wheel as well.
* Repeated entire process above again.

THE PROBLEM:
After closing both bleeders, I was no longer able to actuate the coupler with my large screwdriver no matter how hard I pushed. This leads me to believe that my wheel cylinder may be stuck. Furthermore, I noticed that when I had the left bleeder open (and the right one closed) and I actuated the coupler I could clearly a hydraulic sound of fluid being pushed to the line, whereas when I had the right side open (and the left one closed) I could hear no such sound at all. Fluid came out of both sides without issues so I know the lines are just fine. Before I did this entire process I checked the master cylinder to make sure its working by disconnecting line from the master cylinder and actuating to see fluid squirting out form the back so I know its fine too.

I would like to check the condition of the assembly inside the drum but what makes me hesitant is the fact that I may need a special tool to open the bearing (which looks to be practically new under the dust cap) washer. I believe its a retaining/snap ring washer and looks like this one:
http://www.mrksales.net/images/50012-024_crown_lift_truck.jpg

Might anyone know what is going on here? I would really like the brakes on this trailer to work. Thanks.

 

[QC]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Moved this to trailers to focus the response.

 

[j_martin]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Could it be mis adjusted so the master cylinder doesn't fully retract and allow the fluid to return to the reservoir from the wheel lines and cylinders.

I learned about this the hard way.
A trick used back in the old buyer beware days when brakes had to be manually adjusted is that when they were worn out so much you couldn't adjust them any more, the used car dealer would adjust the master cylinder push rod so it wouldn't fully retract. Felt like good brakes at 1/2 pedal. I know about it because I put a loaded 2 ton dump truck in the ditch with a blown wheel cylinder about 30 miles after I bought it.

 

[DuckHunterJon]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

The special tool you need is just a set of snap ring pliers. You should be able to pick up a pair for a couple bucks at any auto parts store. They allow you to spread the clip and take it off. Just as a word of warning, those are called dammit clips, because just as it comes off the axel, the pliers WILL slip, the clip WILL fly across the garage, and you WILL be saying "dammit, where did that go?"

I'd pop the drum off and have a look, I think it's the only way you are going to know what's going on in there. Good luck with it.

 

[j_martin]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

If the brakes are locked, the master cylinder is not back bleeding, or the wheel cylinders are stuck.

If the brakes are not actuating, the wheel cylinders are stuck.

 

[ufm82]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

LOL- "dammit rings"- That's funny, I don't care who you are.

Been there, done that.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Thanks to all for the responses. Well, I finally got out there and took off the drum, and to my surprise, the brake pad just fell on the floor! Fortunately these brakes were not working prior to this and so all the parts look to be undamaged including the drum. At this point I am more confused than ever. Here is what I observed:

After using a screwdriver to actuate the master-cylinder, I observed the wheel cylinder expand. However, after letting go of the actuator I noticed that the wheel cylinder did not move. I tried pushing the piston back in with my finger but it was impossible. I tried pushing it back in by pressing the brakes and eventually went back inside after a while. After I let go of the actuator it went back to its regular position but was pretty stiff for a few seconds and then allowed me to press again. While actuating, I could hear the hydraulic sound of fluid being pushed in to the lines.

So the confusion is weather it is the master-cylinder is not back-bleeding or if the wheel cylinder is in need of change.

Can I test the wheel cylinder by actuating the master-cylinder and letting go (piston on wheel cylinder still out) and open the bleeder to see if the piston will go back in or be allowed to go back in with ease?

How can I check if my master-cylinder is not back-bleeding?

Thanks again.

If the brakes are locked, the master cylinder is not back bleeding, or the wheel cylinders are stuck.

If the brakes are not actuating, the wheel cylinders are stuck.

 

[Silvertip]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

With a properly bled and operational hydraulic brake system, the coupler should not move very much. Remember -- brake flluid doesn't compress. Reassemble the system, jack up the first wheel and try to spin it while someone operates the actuator. If you can spin the wheel that brake is not functioning. This system is either under pressure or it's not so any wheel that sticks is either adjusted too tight or the fluid cannot return to the master cylinder. If a wheel has no braking action either the components are misadjusted, assembled wrong, or the wheel cylinder is stuck in the cylinder. Just because you can bleed the system does not mean the wheel cylinders are OK. Apparently the master cylinder is functioning properly.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

ADDED PHOTO.

Hey Silvertip,

I totally agree with what you are saying. As a matter of fact, when I was there I did just that. I spun the wheel and quickly ran to the MC and pressed it to watch the drum stop. I tied the screwdriver to keep the MC actuated while I went to the drum and tried to turn it. I was able to turn it but only with force but remember that the primary pad fell off when I first took off the drum so this is not a proper test.

We know that when I actuate the MC the piston of the wheel cylinder comes out. I'm just trying to find out why its so reluctant (for lack of better words) to go back in when I depress the MC and why its just so hard to actuate the MC. You said that you think the MC is functioning correctly, but how did you conclude that it is back-bleeding?

If I remove the bleeder while the wheel cylinder is expanded (piston out) how easy should it be to push the piston back in? I'm thinking, this could be the way I can test the wheel cylinder...

With a properly bled and operational hydraulic brake system, the coupler should not move very much. Remember -- brake flluid doesn't compress. Reassemble the system, jack up the first wheel and try to spin it while someone operates the actuator. If you can spin the wheel that brake is not functioning. This system is either under pressure or it's not so any wheel that sticks is either adjusted too tight or the fluid cannot return to the master cylinder. If a wheel has no braking action either the components are misadjusted, assembled wrong, or the wheel cylinder is stuck in the cylinder. Just because you can bleed the system does not mean the wheel cylinders are OK. Apparently the master cylinder is functioning properly.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

You more than likely need new wheel cylinders. Pull back the rubber and you will more than likely see a bunch of rust in there. Also, the pin that goes into the wheel cylinder should come staright out. The brake shoe that it is pushing against is way out of position. The spring that is on it looks like the wrong spring.

As far as the Clip that you took off to get the bearings off, there should be no clip like that to take off unless you took apart a Bearing Buddy by mistake.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

That spring looks ok after all. This is how everything should look and yours may not look exactly like this. This one is in reverse from yours because it is an opposite side wheel.

You can buy wheel cylinders and other brake parts here.

http://www.championtrailers.com/DRUM BRAKE COMPONENTS.htm

http://www.championtrailers.com/DRUM BRAKE CLUSTERS.htm

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Bruce,

I might as well just get the whole kit including the backing plate. I just want to be sure that it *is* the wheel cylinders that are at fault before I start replacing parts. I also agree that its most likely the wheel cylinder that is faulty but I have no way to diagnose/pinpoint the root cause of the problem.

Aren't there some systematic steps I can take to narrow down which one is the problem for sure? The last thing I want to happen is to replace parts only to find out that other parts were the problem.

You more than likely need new wheel cylinders. Pull back the rubber and you will more than likely see a bunch of rust in there. Also, the pin that goes into the wheel cylinder should come staright out. The brake shoe that it is pushing against is way out of position. The spring that is on it looks like the wrong spring.

As far as the Clip that you took off to get the bearings off, there should be no clip like that to take off unless you took apart a Bearing Buddy by mistake.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Wheel cylinders are the things that fail the most. The newer ones are made out of aluminum to reduce the corrosion problem.

 

[sqbtr]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

That wheel cyl looks fine. The shoes need to be assembled correctly to work. The cyls will not retract on their own, they are pushed back in by the springs.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

That wheel cyl looks fine. The shoes need to be assembled correctly to work. The cyls will not retract on their own, they are pushed back in by the springs.

What makes you think it looks fine? You haven't see the inside to see what the bore looks like?

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Bruce,

I fully understand what you are saying, but again, how can I verify for sure that the culprit of the symptoms I am experiencing are a result of a faulty wheel cylinder as opposed to a MC?


Does anyone know how to diagnose/pinpoint the root cause of the problem or some systematic steps I can take to narrow down which one is the problem for sure?

Wheel cylinders are the things that fail the most. The newer ones are made out of aluminum to reduce the corrosion problem.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

You may not be able to without changing the wheel cylinders first.

Was there fluid in the MC when you started? What was the condition of the fluid...rusty?

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

There was no fluid in the MC, and the fluid that initially came out of the lines at the bleeder was brownish.

I just wish I could test to see if the MC is back-bleeding. When I first started with this entire project, I disconnected the line from the MC and observed how when I actuated it it squirted fluid from the small hole. As for back-bleeding, I don't know how that would be done. I CAN say that before I bled the system, I actuated the MC a few times to see bubbles coming up out of the bottom-center of the reservoir where the hole is. I waited until it stopped bubbling completely and only then bled the lines from the bleeders. Hope this helps.

You may not be able to without changing the wheel cylinders first.

Was there fluid in the MC when you started? What was the condition of the fluid...rusty?

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Well if your master cylinder was empty, you have a leak in one or more places and that includes the wheel cylinders and the master cylinder.

If it was my trailer, I would just replace all of them and be done with it. I speak this from experience with multiple trailers.

Don't get all caught up in the force required to push the cylinders back in...that requires quite a bit of force. If you have ever changed disk brakes before in a car and used a c-clamp to push back in the pistons, you know what I am talking about. I don't believe that is your problem anyway.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Bruce, I did not see any brake fluid leaking anywhere but I can understand why you would lean that way. The person who had this trailer before me did not use the brake functionality for the three years he had it. So in your opinion, if I replace the assembly then the strength of the springs should be sufficient to force the piston back in?

Sorry to be stubborn, but in that case, if I open the bleeder such that there is no pressure in the system, the springs should be strong enough to push the piston of the wheel cylinder back in. Is that a fair assumption?

Well if your master cylinder was empty, you have a leak in one or more places and that includes the wheel cylinders and the master cylinder.

If it was my trailer, I would just replace all of them and be done with it. I speak this from experience with multiple trailers.

Don't get all caught up in the force required to push the cylinders back in...that requires quite a bit of force. If you have ever changed disk brakes before in a car and used a c-clamp to push back in the pistons, you know what I am talking about. I don't believe that is your problem anyway.