Brake Issue on Deuce

[rsites]

I can't find an example quite like this one on the posts so I'm hoping someone can point me in the right direction to start.

When I start up, air pressure comes up and stays good while driving. Brake fluid level is good> While driving though, I have to pump up my brake pedal to get it to be firm "every" time I try to stop. I push as hard as I possibly can with my leg on the pedal once firm, but it only slightly applies the brakes for a slow eventual stop. Forget a quick stop! Kinda feels that either the air or the hydraulic isn't engaging since the brakes never really "grab" even pushing the pedal very hard? Not sure which. I've seen posts about the master cylinder and the air pac being the issue.

Given my description, does anyone have an idea as to what is most likely wrong?

 

[topo]

I would start be adjusting all the brakes .

 

[porkysplace]

When was the last time they were serviced ?
Have you inspected brake lining thickness ?
Have tried to adjust them ?
have you bled them ?

 

[snowtrac nome]

start with a major brake adjustment, pumping the brakes is an indication of extreme clearance in side the drums. As some one else mentioned, if you have to do a major adjustment you should also look at lining thickness, you never know how many times in the past this has been done. drums are going to be hard to come by you don't want to go metal on metal, if you do linings consider re building or replacing the wheel cylinders and springs as they are likely older than the shoes.

 

[frank8003]

Please say as to what level of maintenance already has been done.
How far you been into it already?
One could find all kinds of interesting stuff by performing proper maintenance.

 

[rsites]

All, thank you for the suggestions. I'm no mechanic, but forced to be on this thing at times with no one else around to do it!
One thing I wanted to ADD to the description of the problem. This came on rather sudden. This was not a slow thing to come on gradually. One day she was fine, next she was having this issue.
This makes me suspect more of a problem or failure of sorts, rather than a simple adjustment or bleeding? Never really had to do anything with my deuce brakes, so I could be way off here! It's only used rarely, for parades and such. Very light use, maybe a couple 100 miles per year, and all very local.

 

[cattlerepairman]

rsites, I can only stress what has been said already. THE BRAKES MUST BE GONE THROUGH.

For one, this is not a commercial rig where a quick peek behind the drum shows lining thickness. You need to actually remove a cover on the brake drum to inspect. These are not air brakes with an automatic slack adjuster. You need to adjust the space between brake shoe lining and drum (times 12) because the puny little master cylinder can only move so much fluid which translates into limited brake shoe travel.

"Pumping up" the brakes before they work may well be a symptom of being out of adjustment.

If the brakes feel wonky in any way, please do not drive it until brakes got inspected, adjusted or repaired.

 

[M543A2]

Brake adjustment is a good thing to check, but usually it comes on slowly, not good one day and out the next. I suspect a problem with the valve on the front of the air pack, the one the master cylinder line goes into to trigger the air pack when pedal is applied is not working right, pictured here. Also there is a plug at the rear of the pack air cylinder that is for putting oil into the cylinder to lubricate the packing also pictured here. You need to be sure there is oil in the pack cylinder, but I suspect the valve most of all.

 

[orren]

Your suggested checking the oil level in pack cylinder. What oil do you think would be best?

Thanks,
Orren

Brake adjustment is a good thing to check, but usually it comes on slowly, not good one day and out the next. I suspect a problem with the valve on the front of the air pack, the one the master cylinder line goes into to trigger the air pack when pedal is applied is not working right, pictured here. Also there is a plug at the rear of the pack air cylinder that is for putting oil into the cylinder to lubricate the packing also pictured here.View attachment 701410View attachment 701411 You need to be sure there is oil in the pack cylinder, but I suspect the valve most of all.

 

[Katahdin]

Air tool oil, but don't fill it, just squirt some oil into it.

 

[frank8003]

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