Your Thoughts on this Please - Keeping Rear Drum Brakes Clean

[Daless2]

Rear brake pressurization using York OBA System

I am actively soliciting your opinions, suggestions and criticisms of this idea.

While I have not implemented this on my TJ yet I do believe it has some merit. Perhaps I will after collecting your ideas and thoughts on this.

Problem:

Water crossing, particularly muddy standing water, causes dirt and grit to enter rear drum brakes (Or ZJ emergency brake drum on rear discs).


Potential Solution:

Utilize the York OBA (On Board Air) System to pressurize the inside of rear brake drums, during water crossing, to prevent water/mud from entering the rear brake assembly.

I don’t know how important this might be to the west coast folks, but here in Kentucky just about everywhere you go Jeep’n there is at least one “Standing Water Mud Puddle” or small stream that must be crossed. More often then not there are many of these 12 to 18 inch deep mud puddles to be addressed.

Each time the rear brake drums (or ZJ type rear disc emergency brakes) are subjected to the influx of muddy water and associated grit and grim.

After a good day of wheeling the rear brake drums need to come off for a good cleaning of all brake components.

I am trying to come up with a way to reduce, if not eliminate this influx of water and dirt into the rear brakes.

Operational Design:

Drill and fit the rear brake backing plates with an air nipple that will be connected, via a hose and an electric solenoid/valve to the air tank of a York OBA System.

Just prior to a muddy water crossing a switch in the cab will be turned on to activate the solenoid valve and pressurized both rear back drum assemblies, thus preventing water and mud from entering.


Here is a simple drawing of what this would look like.



Your ideas, suggestions and comments would be greatly appreciated.

Frank

[This message was edited by Daless2 on January 18, 2002 at 02:57 PM.]

[TObject]

I don’t think that this will work with just air – too many holes. How about pumping the drums up with alcohol or some other non-corrosive liquid that is safe for the parts and does not negatively affect performance of the breaks in a big way, instead of air?

[Ace!]

Yeah, it's not air tight, so you can't really pressurize it. I'd think the air might blow out most crud though, just not hold air pressure enough to keep water from entering at all.

Personally though, I wouldn't want additional hoses that I had to make sure were long enough to allow for enough droop, but not so long as to get hung up.

It's a novel idea.

Áron O'Proinntigh is ainm dom

[Milan]

And even if you could pressurize the system, you might then start pushing crap into the axle seals.

So far the best solution I found for keeping brakes clean was to take the drums off and hose everything down after 4wheeling. Sorry.

Milan
The TJ

[Daless2]

Hi folks, the truly great value in putting a half baked idea out for other people to comment on is you almost always get presented with things that you haven't thought of on your own.

As I said before, I don't know if this will work or not, but it does present some interesting thoughts.

There were several comments on the "Air Gap" being too large for the air to be effective at keeping the water and muck out.

Hmmmmm.... I'm really going to have to do some math modeling on this and if it works out mathematically then I will play with a spare D35 I have laying on the floor in the garage.

My original thought was that even though on first glace the "Air gap" between the drum and backing plate seems big (In my mind, I really do have to measure it.), I think it can be overcome.

Why I think this way is the air is compressed between 90 and 125 PSI.

As the air would enter the drum assembly the pressure would drop drastically because of the rather large "air gap" that the air would be escaping out of.

Yet with the drop in pressure there should be a corresponding increase in air flow (volume) as these two properties are inversely coupled.

Also, as long as the air was "flowing out the Air Gap" between the drum and backing plate, there would be a pressure difference between inside the drum and outside the drum.

The question then becomes, will the drastically decreased air pressure and dramatically increased air volume be enough to hold the water and mud/muck out of the bottom of the drum or would it just simply escape out the top where there was no water trying to seep in?

I just don't know. Any hydraulic / pneumatic engineers out there?

Tomorrow I will get a hold of a Physics Professor friend of mine and get the formulas for pressure/flow calculations. Maybe that will help shed some light on this.

An engineer by the name of "2000 TJ" on the JU forum came up with a rather ingenious idea.

Here's what he suggested.

"This may sound really stupid, but hey, I'm an engineer and there is a problem to solve It may be obvious after this proposed solution that I don't get paid for all my ideas!

How about installing a fresh water tank and pump set-up (like RVs have) that could be used to "spray/flood" the drums with clean water after the crossing. Since the problem with the air solution is the gap around the assy, this would allow the water flushing to work. You could even have a line run into the cab and have a drink when you want."


What a great Idea!!!!!!

TObject touched on this one too!

I already have an On Board Fluid System

See:
http://jeepbbs.atinfopop.com/4/OpenT...5&m=6244091061


I think this idea to flush the brakes "Automagically" while on the trail, after a muddy water crossing is very viable.


Right now I can carry 5.5 quarts of fluid in each of two rocker guards, (11 quarts total) and another 10.7 quarts of fluid in the rear bumper.

Can't see why one of these couldn't be filled with water, and under pressure from York OBA system) used to flush the mud/muck out of the drums as I drive!

Great Idea!!!!!

I would still have wet brakes but they would be Clean Wet Brakes!!!

I'm going to give this some focus!

I don't know who paid for 2000 TJ's education but I have the feeling they realize they got their moneys worth!!!

Any other ideas folks?


Frank

[TObject]

<BLOCKQUOTE><font size="-1">quote:</font><HR>Originally posted by Daless2:
Any other ideas folks?
[/quote]

Just make sure you use a loud flushing toilet sound effect.

[Daless2]

Hey TObject,

If I can't handle that physically I am certain I can do it electronically!

Just another set of switch contacts and a teeny tiny circuit!

I'll build you one for your Jeep if you'd like?

Frank

[Tumbleweed]

Frank: You have not been wheelin' enough lately! Step away from the keyboard etc!
Actually I don't know how you are going to get enough air volume to do what you want without sealing most of the brake system. And with high pressure, are you going to be injecting crap into places you don't want it? My real point here was to mention that I have seen Jeepers blow out there drums with a custom,long, air blow gun before. They used a 24" piece of brake line silver soldered to an air gun nozzle. They can bend it where they need it that way. Also, would it be easier to just add discs?

[Daless2]

Hi Tumbleweed,

Thanks for your comments.

Yes your right, I'm having wheelin' withdrawal here. Snowstorm last night killed any idea of doing that today.

I've decided to kill the original idea of using the compressed air in and of itself to pressurize the rear drum brakes for the reasons you guys have stated.

I'm not sure I would have enough air volume to keep the water out of the bottom of the drum without all the air escaping out the top.

However I am gong to do something else.

I will tie together my On Board Air System, with the On Board Fluid System (rear bumper this time).

Air will flow from the tank (via a solenoid valve) at 90 to 125 PSI into the bumper, and clean water will flow from the bumper out a hose for distribution to the brake baking plates.

I will have to do some testing as to how long to keep the solenoid activated but my thought it to turn this on when entering the muddy water, thus putting clean water in my breaks and preventing must of the muddy water from entering.

If the rear brakes are going to get wet anyway I may as well have control over them.

Other then the obvious problem with using this during winter time and water freezing in the bumper, I don't see any downside to this one.

I came across a site last night

http://brakebath.com/product.html

These folks make a boat trailer brake flushing system that you hook a garden hose up to and it works in much the same way for cleaning the brakes without having to take them apart.

I won't be using there product, as I prefer more heavy duty things likes 3 wire hudralauic hose rated at 4,000 LBS for things like this. (AKA almost never break!)

I can put 11.5 quarts, or 2.5+ gallons of water in that rear bumper and it would help balance out my C of G too as I am front heavy.

I'll draw a picture later.

I am planning to install Rear Disc Brakes.

On Blaine's recommendation I want to use the Rear Disc Brake assembly out of the 96 - 98 ZJ which should be a straight bolt on installation and work with my Super 35 axles.

I want to use these, not for cost reasons but rather because of the completely separate emergency brake system that it employs. I like that little drum built into the rotor for a set of small brake shoes that are engaged by cable for the parking brake.

I will use this "On Board Brake Cleaning System" on these little drums built into the rotors when I do this conversion, if this system shows it has some value on my current rear drum system.

I have more creative ideas then you could ever imagine! (Most of which won't hold air any better then my brake drums!)

I really enjoy coming up with something new that solves a problem, even if I don't have all the parts and pieces to it figured out.

I figure if I float the idea people like you guys will give it some thought, throw in your 2 cents and before you know it something viable comes of it.

I don't know if this re-engineered idea will work of not, but I'm going to do it.

I think there is better then a 50/50 chance that for $10 in hose and fittings, and $20 for an air solenoid, I can keep mud and muck out, or at least flush the mud and muck out of the rear drums at will, while on the trail.

That has to be goodness.

After all I take them apart and wash them out when I get home now. Why not do it on the trail and save the work at home.

Thanks again to everyone for your thoughts on this.

Frank

[lynn]

I'm not familiar with the details of these particular drums, but have you considered drilling the drums? (Assuming they're like other normal drums).
Apparently this was big in the 50s on racing circuits, before the common use of discs.

It simply involves drilling a bunch of holes all the way around the drums. This eliminates the build up of gasses under heavy braking and in the use of wet brakes. Seems to me it should give all the grime and grit a way to get out when brakes are applied.
There's a place that does it for ~ $35 a drum. I'll try to find it and post. It should be easy enough to do yourself with a homemade jig and a large drill press...

EDIT: Here's the link:
http://www.chtopping.com/CustomRod4/

Lynn
'71 UNIVRS

[Daless2]

Hi Lynn, thanks for the info.

You won't believe this but you are the second person today to tell me about the drilled drums, and I am just about old enough to remember when the hot rod crowd did this!

I'm not sure if I will go down this route or not as I am planning to convert to ZJ disc brakes, but perhaps someone else will find your info valuable.

Thanks for posting it.

Frank

PS: Living in York, PA do you get the chance to go wheel Paragon very often? I've done it twice and if I lived closer I would do it every weekend!

[sethmark]

Frank,
Are you retired? I've not seen an employed man work so hard in my entire life.

Humpty Dumpty

[lynn]

I'm 2 hrs from Paragon, and haven't been there yet. My wife and I have a weekend place about 2.5 hrs in the other direction that seems to take most of my free time. Last summer, the few free weekends I had were spent on front axle swap/adjustments and distributor drive gear repair... About the only wheelin I've done in the past year is touring my little 15 acre woodlot.
Hopefully this coming summer I'll get to run to Paragon.

Lynn
'71 UNIVRSL

[Daless2]

<BLOCKQUOTE><font size="-1">quote:</font><HR>Originally posted by Seth:
Frank,
Are you retired? I've not seen an employed man work so hard in my entire life.

<A HREF="http://seth.rockcrawler.com[/quote]" TARGET=_blank>http://seth.rockcrawler.com[/quote]</A>

Hi Seth,

Well thank you for the complement. I Think

To answer your question directly I am a retired U.S. Marine, who now owns and manages a small business consulting firm. Mostly defense and aerospace industry clients, but I do have a client who makes lollypops too! (I like going there!)

I do a lot of traveling, thus I have lots of travel time to let my imagination run wild.

I learned early on, that I can have ANYTHING I want in this world, but I just can't have EVERYTHING I want. Thus I have to choose.

I choose my family and country first, my business second, and then whatever my current interests and passions are.

Right now they are Jeeping and perhaps providing a helping hand and guidance to some kids that maybe don't get it from anyone else.

Doesn't leave much time for other things, but it does give me all my time for those things I CHOOSE to give my time too. (Read that I don't let frivolous things I am not interested in to eat my time up.)

It helps too that I am blessed with not needing to sleep much. Four to five hours a night is more then enough.
(Hey I have places to go and people to see and ideas to explore!!!!)

And yes I know this is a lot more answer then you asked for. Forgive me, it's just the consultant in me.

Go after anything you want Seth, with all your passion and you will get it. Just realize you can't have everything, so pick and choose wisely.

I'll stop know before you tell me to be quite.

Once again, thank you for the complement.

Frank

[sethmark]

You're most certainly welcome! Your ideas are not only refreshingly interesting, well thought out and unique, but also completely inane. I'm jealous.

SEth

Humpty Dumpty