400 degree brake drum?

Bounce19712

Petty Officer 2nd Class
Joined
Oct 12, 2010
Messages
109
Hi Guys! I think I have a brake drum problem on my tandem axle boat trailer. Long story short: I had my head unit hitch/ reservoir replaced recently and the drum brakes adjusted.

First time trailering I was really concerned about the heat my hubs were giving off so I stopped every 40 miles for an hour to get to the new boat mechanic 140 miles away. I jacked up one side of the trailer and sure enough the drum brake/ front axel tire was dragging. (the drum brake hubs and tire rims/lug nuts were steaming/boiling water squirted on them from water bottle)

I asked the new mechanic to look at them and he suggested he could back off the adjustment to free up the dragging drum brake.. but when he did a tire spin test the tires spun freely so he did not adjust.

yesterday I drove the boat back home 140 miles stopping once or twice to laser read the temperatures. first time I got 160 on the hubs. back at home in the driveway I got 400 degrees when "shooting" the rim of the brake drum visible behind the tire rim with my laser temp gauge.

driver's side brake drum was 400, passenger side was about 100 degrees less.

unfortunately, I fear there may be an incorrect installation based on the transmission nightmare I had with same mechanic here in my city.

I believe I'll need to take my trailer to a tire shop I trust to look at the brake system...

I have a two inch drop hitch which puts the boat trailer slightly bow down and not exactly straight and level (trailer angle on the hitch) but it's pretty close to correct weight dispersion between front and rear trailer tires.

anyone have any idea if I've killed some hubs, drum brake, bearings etc?

thanks for any input! I've got a good pic I think of my laser temp reader shooting 400 on the brake drum...I'll post later!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,307
your brakes are not adjusted right and your draging

a few things can cause that. sticking backing plates, corroded pistons in the slave cylinders. brakes adjusted too loose and the piston plunger getting cocked

I personally would simply buy two new loaded backing plates and replace the slave cylinders, springs and shoes

400 degrees will bake the grease and melt the seals. suggest you repair the brakes and then re-pack the hubs and get new seals.
 

Bounce19712

Petty Officer 2nd Class
Joined
Oct 12, 2010
Messages
109
thanks for the recommendation!

may your rudder always be wet and your stern always be clear of jetsam and flotsam!
 

Bounce19712

Petty Officer 2nd Class
Joined
Oct 12, 2010
Messages
109
trailer issue resolved with P&M Trailers in Flagstaff. they replaced the back plates. B&T marine and P&M Trailer..... Love it! brake drum temp 120 after getting home. Pete said the seals looked good and grease looked new. I told him I filled the buddy bearings before the 140 mile trip. when I pulled the BB cover on my 400degree side tire I did notice the grease had pushed out and looked curdled but still same blue Lucas color.... ? I pushed for replacing anything he wanted... He thinks I'm good. I feel good

I will remain vigilant on the temp checks and greasing the zircs... any advice on protecting my road trips with latest update? I really do not want to be on the side of the road without cell coverage...holy sheeit you should see hwy89 around Gap,AZ.

Mr Danforth? I've got one of your anchors. Love it :)
 
Last edited:

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,803
There are a few things to do that help drum brakes to keep working well. I assume you are in fresh water, yes?
​Anyway you have to be aware that drum brakes need periodic adjusting and while most people say to adjust till there is light drag, I will go just a bit looser, so there is no drag maybe just a scraping sound, because then when the boat is stored, the brake linings will not rust to the cast iron drums.
​Before using the trailer make sure the brakes do not drag. If they do something is wrong. Causes:
​Internally corroded wheel cylinder (common)
​Cracked brake lining that is being pushed up by rust on the brake shoe
​rusted backing plates that do not allow the brake shoes to retract

​Solutions:
​I water proof the wheel cyls by taking a new one and removing the dust boot. Then put some OMC triple guard grease around the upper end of the piston, and inside the boot. Next I seal the boot to the cyl with some high temp RTV to keep out water. I also put some where the push rod goes thru the dust boot. This will keep out water better and the cyl will not seize up as easily.
​I also take apart the adjuster and coat the threads with OMC triple guard grease. They will seize up other wise. I also use the same grease to lube the sliding surfaces for the shoes.
​Pacific trailers in Cali sells a new design of wheel cyl that uses a boot less design with an o ring seal. I think these will hold up better because water does not sit in the boot like the standard design
​They also sell galvanized or zinc coated drums which hold up better than plain cast iron. I have zinc coated drums on mine and they have held up surprisingly well.

​Everyone likes disc brakes because they are easy to service but here in salt water unless you get the full stainless ones the rotors will rust up just as bad as drums with chunks falling off in a few years. With drums you can just change the whole backing plate every 4 years or so for less than $200 and be on your way. But my modifications will make then work better and longer......
 
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