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Namco brake? issues

wheelieking71

Diamond
Joined
Jan 2, 2013
Location
Gilbert, AZ
So, I am having an issue with my little guy, that I think is brake related.
First off, the brakes on a Namco are about the only aspect of these gems I do not care for.
I started noticing something a long time ago. But, lately it has been getting exponentially worse.
I am about 90% sure this is a brake issue. It is randomly acting like the brake is being applied (while in forward motion).
When this happens. If i simply let it stop, then pump on the pedal a few times it will usually free up (sometimes not).
Or, if I let it stop, then back up a few feet, it will usually free up (sometimes not).
My worst fear is this is actually a hydraulic issue, and not related to the braking system at all. But, it sure feels like the brakes are being applied.
BUT, how the heck would that be happening?! Bye design, this system is backwards. Similar to air-brakes.
The brakes are always applied (by a spring pulling the pedal "up"), and your foot on the pedal (pushing "down") releases them.
I guess I don't understand exactly what is going on inside this master-cylinder? But, I assume it is no different than any other master-cylinder.
A piston in a bore, position controlled by mechanical linkage, controlled by a spring and a bodies foot.
Pressure to the wheel-cylinders in the spring direction. No pressure to the wheel-cylinders in the foot direction.
So, if my foot is on the pedal? How could the brakes possibly be being applied?
To compound my confusion, the master-cylinder is about shot (age I am sure, still less than 1000hrs on machine).
It only takes about 2 seconds for the spring to blow through the entire stroke of travel. I pulled the caps off the master, and it was disgusting inside.
With barely anything left that resemble brake-fluid. I cleaned it out as best I could in place with a sucker, and solvent soaked rags. Then re-filled.
This firmed the apply a little bit. But, the random apply issue (if that is what it is) is still happening, if not worse.
How could I be experiencing an brake-apply condition with my foot firmly planted on the pedal?!
From the diagrams I have been able to find, it appears there is an adjustment at the shoe? It is not obvious at a glance looking at my machine where.
But, my next step is loosen this adjustment, and see if the condition disappears.

Any other Namco owners experience anything like this?
 
Is the linkage on the "passing gear" pedal loose? It could be restricting flow intermittently. I'm just guessing. Mine is rigged solid to the frame since before I got it.

Hmmm, I'll take a look at it. My "passing gear" does function properly.
Another point I should kind of explain a little better:
When this condition happens, the machine does not want to roll/coast. It feels like the brakes are applied.
You know how, if you get a Namco rolling, then just let off the lever? it will coast............(or point it down a hill, again, coast).
When this happens there is no coast. It is like something is either locking up, or the brake is self applying somehow.
If you push the lever for forward motion, it will over come whatever is happening, and move forward. However, it labors to do it.
 
I'm having nightmares this is a hydraulic issue! :confused: :vomit: And, hoping it is a brake issue!
It is pretty flat around my place. I can live without brakes. I can not live without my Namco!
I saw a thread once somewhere (may have been on here?) where somebody was having drive motor issues.
And, a few guys that knew their shit (about hydraulics) told the guy he was pretty much screwed, "scrap it".
That situation would more than break my heart.
 
Your little guy has band type brakes. If, for any reason, there is any pressure on the band when driving forward, the brake will try to "wrap on"
If the push rod/ adjusting rod binds or the spring is broken, missing or the hydraulic wheel cylinder is holding pressure on the rod, I could cause the problem you have.
Try flushing the brake system, but I recon you'll be pulling it apart.
According to the book, it is recommended to repack the wheel bearings @ 1000 hours, so good chance to do that and resolve your brake issue, what ever that may be.

Russell
 
Your little guy has band type brakes. If, for any reason, there is any pressure on the band when driving forward, the brake will try to "wrap on"
If the push rod/ adjusting rod binds or the spring is broken, missing or the hydraulic wheel cylinder is holding pressure on the rod, I could cause the problem you have.
Try flushing the brake system, but I recon you'll be pulling it apart.
According to the book, it is recommended to repack the wheel bearings @ 1000 hours, so good chance to do that and resolve your brake issue, what ever that may be.

Russell

Yea, I am planning a big maintenance day soon. I need to figure out how to get him up in the air.
Like you say, grease job (steer wheel/spindle) as well. And, I am sure it is the original hydraulic fluid/filter still.
It only had 335 hours when I bought it (and, it showed).

Now that I am hyper focused on this, I'm not as convinced it is a brake issue............:(
 
Wheelie,
Russell may be right with the wrap on. The master cyl. could be gooed up enough to restrict flow back to itself. I went nuts and bought new and damn glad I did. These are Wagner numbers:

Master E2796
Wheel WC28720

And another thing. Like you said it's kinda bass akward on the brakes. I drilled a hole in the left panel above the brake pedal and made a lever to hold the pedal down while it sits there lonely and afraid. The first press of the pedal, it swings away. I just can't stand constant pressure on the cylinders. These are external contracting bands. Very basic. Have someone press the pedal while you look at the bands.
 
I'm thinking that there maybe crud slowly building up inside the wheel cylinder. That would account for it slowly getting worse.

Russell
 
Wheelie,
Russell may be right with the wrap on. The master cyl. could be gooed up enough to restrict flow back to itself. I went nuts and bought new and damn glad I did. These are Wagner numbers:

Master E2796
Wheel WC28720

And another thing. Like you said it's kinda bass akward on the brakes. I drilled a hole in the left panel above the brake pedal and made a lever to hold the pedal down while it sits there lonely and afraid. The first press of the pedal, it swings away. I just can't stand constant pressure on the cylinders. These are external contracting bands. Very basic. Have someone press the pedal while you look at the bands.

Ohh I like that idea! Got a pic of how you did that?
 
So, riddle me this: if it did happen to be fouled up brake hydraulics? Why/how would it come and go without me ever letting off the brake pedal?
I could understand if say, a residual valve was fouled/plugged. But, once the pressure does bleed off, how would it come back without me ever applying the brakes?
I will hop up there, press the pedal down, never let it up. And, it will have multiple events of this "binding" condition.
I was on him yesterday for about 30 minutes moving a bunch of stuff around. And, like I mentioned, I was hyper focused to this issue.
It would happen, and I would just let go of the motion control stick. It would stop, like the brakes are applied, and sit there (no coast).
Then I could just roll away like nothing was wrong. Or, maybe back up a foot or two, and it would free up and roll away no problem.

I get what you guys are saying about "wrap on".
And, was pretty much why I want to get to the linkage adjustment (at the shoes), and over-loosen them to see if it stops this.
 
Yea, I am planning a big maintenance day soon. I need to figure out how to get him up in the air.(

The common way is to use the tilt on the mast to lift it off the ground. tilt back and put appropriate spacers under the front of the mast. Tilt forward and add spacers under back of mast. Teeter totter it up adding shims each time. A few of these and it will be up enough to clear the wheels. Only need to go up 1/2" or so, its not as bad as it sounds.
 
Rob,
I'm not so sure of that. If his is like mine, the mast has a simple horseshoe over a pin. To be honest, I can't see if there's supposed to be an end cap or not. You can tilt the mast side to side.
 
Rob,
I'm not so sure of that. If his is like mine, the mast has a simple horseshoe over a pin. To be honest, I can't see if there's supposed to be an end cap or not. You can tilt the mast side to side.

So the mast does not clamp around the pivot, just kind of sits on top?
Can you post a pic of it? :D Kidding on the pic...
 
So the mast does not clamp around the pivot, just kind of sits on top?
Can you post a pic of it? :D Kidding on the pic...

Rob,
Yep, as far as I can remember when I had the wheels off there was just an upside down U sitting over a pin.
Someone else may chime in and correct me.
 
The older book I have, that matches my machine, shows band brakes. The 74-75 book I have shows drum brakes.
The older book also shows an optional hydraulic brake lock. I guess you ordered that option of you were in the NAMCO drag racing circuit of yesteryear? :nutter:
Both books also show a parking brake gear and pawl system that I don't see on my machine. That also must have been an option.
Is it possible that, on your machine, the master cylinder isn't retracting enough to open the port to the reservoir with the pedal all the way down? Air in the line could be expanding with nowhere to go.
You are right, if I go forward and let go of the lever, it coasts to a stop.
 








 
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