VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Wheel Cylinder Pistons Sticking

My 41 Coupe has been sitting for a couple months. Now the several of the dang wheel cylinder pistons are stuck. Now got to take and tear down a wheel or two. What a mess.

Do you folks up north - who store your cars all winter - have this problem?

Other than going out once in a while and mashing the brake pedal, is there any trick to keep them from sticking?

Charlie

Really...I hadn't heard of this before...Happening after mere months of inactivity...I don't think this would be a problem exclusive to northerners...

Charlie I believe this just another one of those unfortunate situations...Besides, your out there giving "your baby" xx & oo's everyother day to keep her from being lonely...Why not add a couple of pedal mashes to your repertoire... smiles

Just another reason to have the wheel cylinders and master lined with brass or stainless.

Ray,

Well, I suppose so.

Anyhow, I took the front wheels off and took a hammer and sorta knocked the shoes back and forth 'til I could tell the adjusters wuz moving. Seems to be ok now.

Shade tree at its best.

Charlie

Really...? I'll have to try that on mine up front...They've been stuck for years...lol Sounds easier than rebuilding...

I have had that happen, usually with brakes that had not been serviced for some time and were inactive for quite awhile. I wonder if the brakes were bled every year or two it might help stop that. Seems like it never happens if the cars are driven but I think they take on moisture from condensation when they aren't used much. Not much fun to bleed them though and getting harder every year!

Well...When the brakes aren't used air leaks in up to and past the rubber seals....Mixing with the fluid and it just sits there and starts corroding the cast iron bore, particularly around the lip of the rubber...
Which reminds me of a problem I used to have when I'd let it sit for a year or more w/out releasing the hand-brake...Just the back wheels would stay locked-up even after releasing the brake...Have to push or tow the car, sliding along until BANG and parking brake shoe and piston would return to normal position and I'd swear not to leave the parking brake on again for that long...Something to think about if your storing the car...Leave the hand brake off...

Actually moisture will penetrate the brake system past the rubber covers on the wheel cylinders and also the brake hoses. Actually past is also "through". Yes there is a rate that water molecules will pass into and through rubber. If the fluid or rubber parts are heated it tends to drive the water vapor back into the air. We leaned that during extended testing of silicone brake fluid. Took some time to figure how water droplets could get into the brake systems and then freeze causing brake failure. First though it was poor technique allowing moisture to enter the brake systems when they were being assembled and filled. When it occurred after scrupulous precautions on assembling and filling systems it forced us to look for other causes. When we finally considered the rubber parts might allow moisture through, and tested rubber samples for water and moisture transmission we found the culprit.

It is also the main problem causing premature failure of trailer tires. Water passing through the tire rubber into the belt/rubber bond begins to corrode the steel belts. That causes a weak spot in the tire construction. Continued flexing and or corrosion eventually throws off the tread. The liquid water forming steam can also create a bond break on bias ply or kevlar or fiberglass belts but takes much more time. Trailer tire manufacturers are now realizing that it is not UV light on the trailer tires but moisture. Of course that does not prevent people from covering the tires or selling the covers.

Oh no, does this mean I wasted my money on tire covers for my '47...?

As long as the tires are off the ground then covers may make a difference. If the car is stored inside then they are basically useless as the building will likely provide the UV and moisture protection. Besides covers are primarily a look good item.

The primary reason for the tire covers is...I don't own a gun...

In my present situation, the car is parked out on the drive and there is a feral tom cat that marks my tires...For awhile I left cardboard covering the tires but the wind would blow them over...I've tried trapping the culprit but he's wise to that...

The moisture enters the vent in the M cyl. Brake fluid, as you know, is very hygroscopic and loves moisture. Thus, out-of-use brakes readily rust and corrode rapidly.

Later cars/trucks use a bellows-type M cyl gasket that maintains an air seal while allowing fluid freedom of movement. If we could get someone to produce the M cyl we need that had the bellows type seal, we wouldn't have much of a problem with our "old style" brakes.

In the past, I have used silicone brake fluid (DOT 5) to prevent moisture problems. Seemed to me it worked. I haven't used it in years. Now, Chipper tells us it, too, had moisture problems.

One thing I quickly learned - in bleediing silicone fluid, DO NOT pump the pedal. This entrains tiny air bubbles into the fluid that are almost impossible to get out. I work the pedal by hand, very slowly, both up and down. Then, you don't get the bubbles. Frankly, I had good luck with silicone fluid in at least 3 vintage cars plus a '66 GT Mustang that I drove very hard, daily, for several years with no problems.

FWIW, I left a set of complete '40 Lincoln front brakes out in the weather with the hoses open to atmosphere for a year (rain, etc.). I then put 'em on a '47 (F0rd) convertible. Had DOT 3 fluid been left in 'em, the wheel cylinders would have been junk. With the DOT 5 fluid, easily I took the cylinders apart, wipped 'em out and put 'em back together - absolutely no rust or corrosion!

Caution, If you ever use DOT 5 fluid, make sure you have ALL of the DOT 3 out of the system. I have only used it during a complete rebuild with all lines open. I flush the system with denaturte alcohol using the old M cyl as a pump. Then, I blow the lines out with compressed air. The 2 fluids will not mix (even though some DOT 5 labels say they will).

Back to my brake problem.

Drove the car across town to a friends place to pick up some pecans. On the may home the it was a-grabbing at the right front something terrible. Engine wasn't running very well either.

Bottom line:

a. I've got to go through the front brakes and put new shoes on and clean up the mess. So much for the clever (?) hammer method.

b. Got to figure out why the engine runs beautifully going someplace but doesn't run worth a ______ (fill in a suitable word) after sitting for a spell and then on the way home. It's been doing that for a while. Doesn't want to idle at stop lights for one thing. Even a stubborn mule will want to go home! Mercy!

Except for the project, this is my last 216. Even the 50 will get an updated to a 235 or 261.

Charlie

BTW: I acknowledge that the engine problem lies in me rather than the 216 engine. But still...

Charlie

if your wheel cylinder pistons are O.E. and aluminum it is possible that what you have is called galvanic corrosion. Whenever aluminum and steel are placed together an electrochemical reaction takes place often leaving a white residue and bonding the parts together.
The auto industry realized this years ago and started anodizing those parts and for years now you have probably noticed the blue and red pistons. An anodized piston can also have a normal metallic color depending if a dye was added during the process or not.

Maybe time to get new pistons and rubbers. If the bore of the cylinder is still in nice shape that service would last for a long time. I did all 4 wheel cylinders on my '50 a few years back and had trouble with one of them leaking. I put new pistons and rubbers in and have had good luck since.
Don

I think I need to get me some of those new pistons. Mine sure are the corroding kind, all right.

Thanks,
Charlie

I hate to tell you this Charlie, but a 235 or 261 will run just like your 216 if the same thing is wrong with it.

Sounds like dirt in the carb to me.

Eastern Ed,

I know. It's just a mental thing. I ain't just right, you know.

Charlie

C37,

It may be dirt. Guess I'll have to tear it (carb) apart. Something is sure wrong.

Thanks,
Charlie

Actually, Charlie,
It is just because the coupe is a '41, you know, December is traumatic for '41s, all that Pearl Harbour stuff and all of that getting into WWII stress and strain, when the 41 was in that pre toddler stage and it's self esteame was permenantly twisted. Maybe it will straighten out after Jan.1st iffen you don't drive it offen the Fiscal Cliff! Drive it over to Harbour Freight and fill it up with some of their Chinese made accessories.

OH shoot! my smiles won't work, must be that dreadful December syndrome?...or even worse the Fiscal Cliff pre-emotional fear syndrome...R A T S!

BTW, Charlie If I don't get to talk to you because the '41 stranded you across from that nudist colony....MERRY CHRISTMAS!

WOW!!!

Here we are in the "Mr. Goodwrench - Technical » Mechanical - Engine, Trans, etc" forum trying to solve a sticky wheel cylinder problem and we kind of morphed over to a rough running engine topic because of the stories told, and now MrMack cleverly explains why '41s have so much trouble, then ends it with a big Merry Christmas alongside the nudist colony.

I think it's time to get back on topic and stay technical.
Thanks for your cooperation.

ken48
Chat Moderator

(The Moderator with no sense of humor)

Ken48,

Thanks for your diligence. The topic got off track owing to my not paying sufficient attention. I'l truly sorry. I keep forgetting that the thread should stick very closely to the original subject. My bad.

MrMack,

I apologize to you, too. Although your thoughts were well received here, in the future please pay attention and don't let me lead you down the wrong path again. I don't want you or anyone else to be censured because of my ineptness. Really.

To all:

I will report on the sticking wheel cylinder pistons as soon as it warms up enough for me to get at them. I'm hoping that a general clean-up will do it.

Charlie

BTW: Please note. None of the above is meant as sarcasm in any way. It is heartfelt. After 78 and a half years, I should have learned to follow simple rules and deserve to be chastened when I don't.

I have not been reading the posts but this is my experiance with sticking wheel cylinders.
First sticking was a problem when these cars were new. Ofter occured after a few years.
If first time honing the wheel cylinders is OK. Piston is aluminum and will "re-stick" faster if reused. New are the best but not easy to find new pistons today.
I experimented with Silicone fluid and did not help. The last time I rebuilt/replaced the wheel cylinders I coated the pistons with silicone grease and more or less packed the area between the piston and adjuster cover with silicone grease. At this time it has been at least 10 years with no problems.
The Bendix brakes have the rubber boot over the ends of the wheel cylinders which prevents moisture from getting at the piston.

Gene,

Thanks for the grease hint. I haven't tried that. Not doing so owing mostly to the fear of getting grease (somehow) on the shoe contact surface.

I wish the Bendix rubber cups were on the 36-50 but alas they didn't start until 1951, I believe.

When I get around to looking to to the problem, I'm going to do as you did and coat the edge (facing the cylinder wall) with some silicone grease.

Thanks again,
Charlie