Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

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?

Absolutely. The springs are strong enough to push them back even without undoing the bleeder screw as long as the bores of the cylinder are in good shape.

As far as not seeing any evidence of leaking brake fluid, that is totally normal. It usually doesn't leave a telltale stain unless you catch it right when it is leaking.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

I see! Then in that case, a good test for a wheel cylinder that is suspected to stick out, is to open the bleeder and see if the springs push the cylinder back in. I will do this.

Also, one more thing, is it possible to take out this piston and inspect or clean/fix the bore? Sorry I don't know too much about this. I'm sure you will know. Thanks.

Absolutely. The springs are strong enough to push them back even without undoing the bleeder screw as long as the bores of the cylinder are in good shape.

As far as not seeing any evidence of leaking brake fluid, that is totally normal. It usually doesn't leave a telltale stain unless you catch it right when it is leaking.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

I tried this a long time ago and not worth it. They are so cheap that it is best to replace. Same thing goes with repairing master cylinders. The reason all of these fail is not the seals but the bores corroding so there is nothing you can do.

 

[bassman284]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Without looking I'm guessing a wheel cylinder hone these days would cost about as much as the new wheel cylinder itself.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

So I hope to get out there tomorrow and I want to make sure I utilize time. Is there any way that I can test the master cylinder to make sure its back-bleeding?

As I said earlier, I will test the wheel cylinder to see if it goes back in when I unscrew the bleeder.

I tried this a long time ago and not worth it. They are so cheap that it is best to replace. Same thing goes with repairing master cylinders. The reason all of these fail is not the seals but the bores corroding so there is nothing you can do.

 

[sstocker31]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

I know that everyone is suggesting to replace the wheel cylinders, but if you would like to check it, just remove the brake shoe on the actuator side, remove the rubber dust boot and actuate the brake master cylinder until the cup pops out. Brake fluid will spill everywhere, so have some brake cleen handy. Check inside the wheel cylinder for corrosion or score marks.Clean throughly and evaluate what needs to be done. Assembly can be kind of tricky....getting that damn seal back in the hole.....just make sure that everything is clean. Having the bleeder open while doing this helps relieve pressure buildup as well.
As someone also said the actuating rod coming out of the wheel cylinder need to come straight out to the brake shoe, not at an angle like it is in the pic in post #9......Are those the correct brake shoes??

 

[sstocker31]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

OK....I just finished replacing my master cylinder last week and thought a video of the internals may help you with problem solving. I had a tough time pulling this apart because of the amount of crap in there....so that could be part of your troubles too.

Heres the vid

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Hey Stocker,

Thanks VERY MUCH for creating that video for me. It raises a question I have: If fluid is allowed to go one way but not the other, what exactly does back-bleeding mean and how can it be checked? When I actuate and then de-actuate the MC, how does the piston of the wheel cylinder go back in?

Thanks again...

OK....I just finished replacing my master cylinder last week and thought a video of the internals may help you with problem solving. I had a tough time pulling this apart because of the amount of crap in there....so that could be part of your troubles too.

Heres the vid

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

When I actuate and then de-actuate the MC, how does the piston of the wheel cylinder go back in?

The springs on the brake shoes pull it back in.

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Yes, of course, sorry. If fluid is allowed to go one way but not the other, what exactly does back-bleeding mean and how can it be checked?

The springs on the brake shoes pull it back in.

 

[four winns 214]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Nice video of the brake master cylinder. What the video shows very well is HOW the master cylinder works, not how to replace it.

If anyone is contemplating replacing their brake master cylinder, $65 will get you the complete Atwood assembly that you see taken apart on the video. It is not necessary to disassemble the master cylinder when replacing it. It's pretty much plug and play the whole assembly. I did just that a couple days ago with the very part shown in the video. I also changed the brake assemblies. I elected to use complete new assemblies ($125 for the pair). That way there was no question about the springs or wheel cylinders. The brakes now work FABULOUSLY. I would rate the job as moderately easy, well within the capability of a boater with some tools and average homeowner skills. You will need a floor jack.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

For some reason you have this notion that if the wheel cylinder is extended and the spring tries to push fluid back up to the master cylinder that this is not happening with your system. This is supposed to happen. Happens all the time when you change a disk brake pad. You manually push the cylinder in and the fluid goes into the master cylinder. This will happen as long as the master cylinder is in its neutral position. Once you start actuating the master cylinder, this obviously won't happen because your brakes won't work.

Are you still in the process of determining if your wheel cylinders are good and the master cylinder is good?

What happens when you have the whole system bled, all the springs and shoes are in their proper position and you apply the master cylinder? Do the wheel cylinders get stuck and don't retract.

You are asking a lot of questions but you aren't stating what you have tested.

Brakes are petty darn simple and the brakes you have have not been in service for many years. Corrosion takes its toll and if I were you, I would start with a clean slate, bite the bullet and at the minimum replace the wheel cylinders and possibly the master cylinder. The wheel cylinders are less than $30 each. If you don't replace the master cylinder you are betting that no corrosion occured while it was sitting dry for who knows how many years and that is why I would replace it too. Depending on your coupler, you are talking less than $80 for that.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

And by the way, there is a procedure called back bleeding where someone bleeds the brakes by forcing brake fluid from the wheel cylinders up to the master cylinder. This method of bleeding brakes is NOT recommended because it forces whatever crap is in the line into your master cylinder.

This is obviously not the way you re trying to bleed your brakes but you are using a term that does not mean what you are trying to say.

 

[sstocker31]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

As BRUCEB58 pointed out, the "back bleeding" is done with the brake springs. To check if its your master cylinder preventing this action, just undo the brake line connection at the master cylinder and see if that allows any action.
My master cylinder had alot of rust and junk in it, and this was preventing smooth operation of the piston......which would prevent back bleeding if the piston was depressed.

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

My master cylinder had alot of rust and junk in it, and this was preventing smooth operation of the piston......which would prevent back bleeding if the piston was depressed.

If the piston is depressed, no fluid should get past the piston. If it is, your seals are shot in your mater cylinder. Fluid can only get back into the master cylinder if the piston is NOT depressed.

My suggestion is replace tha parts(wheel and master cylinder), bleed the brakes and you will be done with it. For the amount of time spent writing about it, you probably would have them fixed already.

 

[kilowatts]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Hi Guys:
Having been in the same situation myself this year I feel that Sstocker is right in his diagnosis and very thoughtful in his video production. I replaced all the brakes, backing plates, bearings, lines, connectors, wheels, tires and fluid only to find the wheels on my tandem set up were often locking after braking. Turns out the master cylinder in the actuator was full of rust and crud so I replaced the actuator as they were on sale at Princess Auto (Canada's Harbor Freight). After all that trouble, I did enjoy the process and now I'm sure I have no more issues.
kilowatts

 

[sstocker31]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

If the piston is depressed, no fluid should get past the piston.


What I was trying to say was when the piston was depressed and then released it wouldn't smoothly slide back into its resting position, and therefore prevent back bleeding.....sorry for the confusion

 

[E_Man]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Stocker,

Thanks again for making that video for me. It inspired me to go out today and take apart my master cylinder as well just to make sure the issues aren't there. I attached a few pics as well as a small video just to be detailed. Please let me know what you think of its condition. When I first opened the reservoir, the inside was full of crud and dark brown liquid came out of parts as I took them apart. However, once I sanded the inside down a bit with sandpaper and a screwdriver (especially around the holes at the bottom) and cleaned with WD-40, it started to look much better. I notice in your video you said that something was clogged. Where might this be here on my MC? I also noticed that there are two holes on the bottom of the reservoir, but only one of them actually goes through to the cylinder (right on pic)whereas the other one seems plugged! (left on pic)

After cleaning and testing, I actuated it the MC and could hear the air shooting out of the hole. As a test, I plugged the back hole (where the brake line goes) with my finger and actuated and de-actuated the MC, then removed my finger from the hole to feel a suction sound. I assume this is what is supposed to happen and shows that the MC is trying to suck back the liquid from the lines even though when I de-actuated the spring extended inside and forced the MC to the extended position?

Please let me know what you think! Thanks again.

OK....I just finished replacing my master cylinder last week and thought a video of the internals may help you with problem solving. I had a tough time pulling this apart because of the amount of crap in there....so that could be part of your troubles too.

Heres the vid

 

[bruceb58]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

Buy a new one. If it had any rust in there, its toast.

 

[sstocker31]

Re: Bleeding Surge Brake BLUNDERS - Wheel Cylinder stuck?

I actually inspired someone???!!!!......AWSOME!!!!!


Well glad to see your still at it. The last pic you showed ...the piston with the black disc and six holes is the part of mine that had bypass holes that were plugged. Maybe the holes are hidden by the black disc. Your MC is different than mine so things are bound to be different.
It's clear to me that you would rather fix this than buy a new part, so clean it up as best as you can.....get rid of all the rust, and flush everything very well to get rid of all the contamination, reassemble all the parts, and then bench bleed the thing ( to get rid of all the air, and to ensure smooth operation) before installation.
Your going to have to flush the brake lines and get all the old brake fluid out (if you haven't already), and make sure you pop the dust caps off the wheel cylinders to check for rust and ensure smooth operation of the piston (depress with a finger,screwdriver or whatever.) If you can't move the wheel cylinders, they need to be either replaced (they're really cheap), or worked on as well.

Keep us updated with your progress....good luck