Soft brakes

[JBog]

In the midst of parade season. I noticed when driving to the parade my brakes are crisp and work fine, by the end of the parade, the brakes feel really soft and I ended up using the hand brake a few times. What could be the problem or is that normal?

I am running Rocky Mountain Brakes in addition to the standard equipment.

[RajoRacer]

Sounds as though an "adjustment" is in order.

[Art M]

What is the type of lining.

Art Mirtes

[TXGOAT2]

Frequent use of the brakes may cause the bands to heat up, expand, and loosen slightly.

As long as you have a reasonable aount of pedal reserve above the floor board, you should be OK.

Tightening the adjustments may help pedal feel, but overtightening will cause problems.

Be careful not to "ride" or drag the brakes, which will cause rapid heat build-up. Be sure the pedal and all brake linkage releases fully when you take your foot off the brake.

Be sure brakes are not adjusted too tight, which will also cause excess heat build-up.

[Norman Kling]

I don't know whether or not you have Ruckstell or other auxiliary transmission? But if you do, you can do as I do and put the transmission in a lower range and pull the parking brake lever to the neutral position. Then wait until the unit in front of you moves up a bit and then tap the low pedal. Let it coast in neutral as far as it will and then tap the pedal again. Only use the brake if you need to stop before you hit someone in front of you. Also weaving back and forth along the route if you have room to do so helps. Anyway, I also have Ford transmission brakes and Rock mountain brakes on my cars and have had no problems.
Norm

[JBog]

What is the type of lining.

Art Mirtes

Wood

[Moxie26]

I would tend to believe the metal bands are expanding from the heat given the effect of a lower pedal, regardless of what liner is used

[Craig Leach]

Hi Jason,
Start with Steves suggestion & work your way down they are all very valid ideas. I do many parades in the fire truck and don't remember ever
having that issue. I use the under drive low peddle & coast method & find it works well. I'm looking forward to the next parade as I just
replaced the Muncie with one with reverse in it & installed a 10 tooth pinion. Reverse Muncie & Ford reverse is super low forward.
Craig.

[JohnM]

Check the brakes for grease leaking from a failed axle seal.

[JBog]

Thanks, everyone! Ill check it out

[TWrenn]

Check the brakes for grease leaking from a failed axle seal.

He'd have to have a LOT of grease leajing out in order to "get up outside" on the RM's I would think. They do get themselves out of adjustment with that "knob" on top of the threaded rod adjuster. Also need to adjust the clevis on the rods as the shoe linings wear. I found that to make a BIG difference.

[JohnM]

Happened to me. If you regularly pack the grease cups, or worse use a grease gun, the excess is pushed out and drops down on the inside of the drum. When driving, the centrifugal force flings it out between the drum and backing plate. I am not convinced this is the problem, but a two minute check will rule it out before spending more time making unnecessary adjustments looking for the problem elsewhere.

[TWrenn]

Yeh but how is grease gonna make its way up to the top outside of the RM drum, especially since it's essentially totally covered by the break shoe anyway?

I say it's an adjustment issue. I've had mine do that similarly on long tours where the route required a lot of braking. That "top adjustment nut" is not very secured...it only uses a small detent to stay in place.

[JohnM]

I have a 26 with large drum rockies, if grease leaks out between the drum and backing plate it will immediately get on the brake pad. Tim, I am not suggesting you are wrong, just offering a tip based on my experience.