M35 Brakes. Warning signs ignored could have been serious

[Barrman]

I have noticed what seems to be an oily film on my drivers side running board and inner fender the last week or so. I have a plastic 5 gallon jug of fuel sitting there and figured it had a pin hole leak or something. I also had a little mess on the frame rail above the axle. I figured that was just residue from cleaning out the secondary filters, a slight leak on a return line I fixed a month ago and possibly from a retouting of the flame heater supply line to the injector return lines once the heater injector started leaking. To put it another way, I ignored the obvious signs.

I moved the truck Wednesday so I could change the oil and install a Jatonka spin on oil filter set. My brake pedal was soft. I checked the fluid and it was down just a little. I topped it off thinking the vent line might have been leaking a little since it wasn't all the way tight like I thought I had left it. The pedal was hard when I tried it. Again, I ignored the now obvious signs.


Before work Thursday, I was up early because the brake fluid thing basically wouldn't let me sleep. I used a flash light to look at the inside of all the tires and found the problem. Drivers side front wheel cylinder was leaking. The tire was throwing the slimy compared to DOT 3 BFS on the fender, frame rain and running board. I mis took it for diesel residue. Anyway, I pulled the wheel cylinder and found a mess. Rebuilt version put in and all is well. The pictures below show the reisdue I should have recognized and the bad wheel cylinder.

 

[gimpyrobb]

Wow! That looks narsty.

 

[wsucougarx]

Wow, I'm glad you caught it in time before venturing out onto the road. And wow look at that cylinder:-0.

 

[196thprober]

Thanks for the very informative post!

 

[jasonjc]

If one looks like that they all do. You need to change them all out and flush out all the lines.
I use one of the brake bleeder that recovey4X4 use full of denatured alcohol to flush the lines out. Then a another one with dot 5 to bleed it.

 

[Brock Steel]

You read my mind A full overhaul is needed. Stopping is more importation than going.

 

[Snarky]

"Does it run?"

Oh hell yeah, runs like a beast, you would be hard pressed to kill one of these...

It just doesn't stop!

 

[Speddmon]

Barrman,

First off, thanks for the informative post about safety....you can't be too careful when the brakes on these beasts are concerned.

It sounds like you and I are alike....if I saw an oil slick like that I wouldn't be able to sleep either until I found the source, as I would be afraid it was the brakes.

jasonjc is right, You need to check out the rest of the wheel cylinders as well and then flush the lines out real good. Personally, I would do the flush before the wheel cylinder changes, just because I can't think of an easier way to do the flush than through the bleeder screw. And by doing it that way you run the chance of getting a piece of heavier gunk in one of your new wheel cylinders. I would flush first then change the cylinders and rebuild the old ones so you have spares. Of course after you replace the cylinders you need to bleed the system again. Denatured alcohol is great for the flush. With a pressure bleeder it's an easy job to do. I made mine real easy out of parts from my local hardware store. I'll take some pics and post them up later today if anybody would be interested.

 

[Parker2]

^^^I would be interested.

 

[dcwilkie]

Me too!

 

[Speddmon]

Here it is.

The garden sprayer was the most expensive part...I think it was $12.99. I didn't use the wand or tube and tube nuts that came with it.

3/8" o.d. by 1/4" i.d nylon tubing was something like $0.15 / foot (I used 3 feet)

3/8" spring clamps were less than a buck.

The air tool coupler set was something in the neighborhood of $4.99.

I picked up the MC cap at the scrap yard with some other parts so I say it was free, but it was figured in with the rest of the parts I picked up.

Easy, one man brake bleeding...PRICELESS!!!

 

[Barrman]

Thanks for the advice. I flipped the hubs to put on singles a few weeks ago and looked under the dust caps of each rear wheel cylinder. Squeaky clean. That is why this bothered me so much. I pulled the front hub covers off when I got the truck a year ago and found fresh clean grease, so the fronts had been maintained. That is why I wasn't thinking brakes when I saw the residue. The passenger side is getting pulled apart the next chance I have.

I also have a pressure bleeder. I love it. Last weekend I replaced the master on my M715, drained the brake system of DOT3, flushed with alcohol and refilled with BFS.

Because my Gasser had been sitting for about 20 years, I started looking for brake parts as soon as I got it. I know I have 4 more wheel cylinders that are either new or rebuilt with new parts. I have to check and see which of the other 6 or 12 yet to be messed with ones are best and compare them to what I find on the passenger front.

 

[ecostruction]

I hate to be an idiot, but what's the process for bleeding with the above setup? I get the construction of the tank, etc., but is the tank just to create compressed air? Or do you put the alcohol and then the Dot 5 in the pressure tank? Then pump, then bleed at each wheel according to TM. Seems it could be just the compressed air that you need. In place of another person pushing on the pedal.

 

[jasonjc]

Yes you fill the tank with the fuild of choice. Then it keeps the MC full and under pressure. So you can bleed by your self (brakes that is).

 

[Speddmon]

^ what he said

 

[swbradley1]

Yes you fill the tank with the fuild of choice. Then it keeps the MC full and under pressure. So you can bleed by your self (brakes that is).

I can bleed with or without someone and I'm not talking brakes...........

 

[Barrman]

It also makes it so you can attach a hose and direct what comes out to a container so no mess is involved.

 

[Keith_J]

I hate to be an idiot, but what's the process for bleeding with the above setup? I get the construction of the tank, etc., but is the tank just to create compressed air? Or do you put the alcohol and then the Dot 5 in the pressure tank? Then pump, then bleed at each wheel according to TM. Seems it could be just the compressed air that you need. In place of another person pushing on the pedal.

Yes, you could bleed with only pressure on the MC. But you would have to fll the MC every wheel. The pressure reservoir makes the job much easier, just have a hose with a container, slip it over the bleeder screws and loosen until no more bubbles.

Remember to bleed the booster first.

 

[littlebob]

Too add to Barrmans experience
I've changed all the parts, but over a year or so period and now I'm reaping the negative results. The front wheel cylinders which I replaced first are leaking. I'm sure I got moisture in the system changing one component at a time over the long period with the rear jacked up with the drums off the back and not being able to properly bleed the brakes after I changed each part.
It's been said before to always do a walk around as the truck is warming up and check everything and all of the fluids should be checked before even starting(including the brake fluid).
Never completely trust the brakes on a single circuit system that the Deuce. When you do a walk around always look for drops of fluid on the brake components as even one is a sign of a problem.

 

[BugEyeBear]

Good Thread!

Always good idea to check Deuce brake systems OFTEN for leaks. Especially since it is a single circuit system.

I always look underneath my M211 at the inside of every tire/wheel before and after each drive.
Call me paranoid, but I just want to always know that I will be able to stop!

Probably a good idea to bleed your brakes evey year, as it is the moisture absorbed by brake fluid that kills these things.
On my race cars we bleed the brakes prior to every race. (Again, I just want to know that I'll be able to stop!)

DOT 5 fluid (silicone based) resists moisture, but it has some disadvantages.
-You can't mix DOT 5 (silicone based) with DOT 3/4 or DOT 5.1 (glycol based).
-DOT 5 doesn't absorb moisture, but it also doesn't disperse moisture as well so annual flushings are highly recommended.
-DOT 5 might not be compatible with some brake rubber parts.
-Typically DOT 5 is not compatible with ABS systems. This is because the DOT 5 fluid is more compressible than DOT 3/4 or DOT 5.1.

For more info:
D.O.T. 5 Brake Fluid

If you take care of only ONE SYSTEM on your vehicles make certain it is the brakes!

"Cheers!"
-Bear-