Brake Sensitivity, Sudden Stops

[C2500Ryan]

Afternoon gents,

I was hoping to post my issue on here and hopefully get some insight to what may be happening to my brakes.

I recently purchased a 1995 C2500 and everything was working perfectly, had everything inspected to ensure it was in daily driving condition.

Last week I started it up in the morning and started to drive per usual. I pressed the brake pedal very slightly as I approached a stop sign, and the truck suddenly lurched to a halt and seemingly locked up.

I took my foot off the brake, and let it roll some more thinking it was a fluke or something and pressed it again at the stop sign. Same result.

I drove the rest of my route, and the brakes behaved normally, with no sudden stops and everything was operating as it should.

This has happened a couple times over the past 2-3 weeks, with 95% of the occurrences being in the morning when I’m first driving it.

This is the second truck I’ve ever owned, and the first with drums so I am a little inexperienced. If anyone has any insight or possible solutions I am all ears. I plan on taking it in to get inspected in a day or two.

Thanks,
Ryan

 

[Erik the Awful]

Drum brakes are self-actuating, meaning that once you press the pedal, the friction material pulls itself tighter. If one of your brake springs has broken, it could be causing the issue. I'd pull the rear drums and check to make sure everything's in good shape. Make sure you still have plenty of friction material, make sure there are no foreign objects or buildup of crud, and make sure all the springs and levers are in place with no cracks. Before you reassemble, take the opportunity to adjust the star wheel.

 

[Gibson]

Your experience is common, especially in cold/damp weather.
Cold drums/shoes are quite "grabby", much more so than discs.
Once the shoes "drag" a bit they warm up and smooth out.
The effect is multiplied if the rears are out of adjustment.

 

[Pinger]

My 1999 C2500 does the same. As I'm manoeuvring off the driveway just brushing the pedal is like hitting a brick wall. Once I'm off the driveway it's completely forgotten about until the next time I'm leaving the house.

Post # 3 gives the explanation of why.

 

[KLR TOMMY]

Another possibility is contaminated brake shoe material either from a current or previous leaky axle seal or wheel cylinder. Usually the symptom of locking or grabbing goes away after the first or so brake application. There are some hacks that may or may not work to decontaminate the friction material to an acceptable level.

 

[Supercharged111]

My truck has only done this to me back in MI in damp weather. Crappy shoe compounds can do this too. Or a shoe soaked in fluid as was previously pointed out.

 

[C2500Ryan]

Your experience is common, especially in cold/damp weather.
Cold drums/shoes are quite "grabby", much more so than discs.
Once the shoes "drag" a bit they warm up and smooth out.
The effect is multiplied if the rears are out of adjustment.

Thank you sir!

 

[C2500Ryan]

Drum brakes are self-actuating, meaning that once you press the pedal, the friction material pulls itself tighter. If one of your brake springs has broken, it could be causing the issue. I'd pull the rear drums and check to make sure everything's in good shape. Make sure you still have plenty of friction material, make sure there are no foreign objects or buildup of crud, and make sure all the springs and levers are in place with no cracks. Before you reassemble, take the opportunity to adjust the star wheel.

Appreciate the insight!

 

[thinger2]

Yep, the rears will stick when cold for a bunch of different reasons.
Worn, out of adjustment, adjusters rusted and not working, worn backing plates, busted springs, cracked linings,
and on and on.
Do a good quality no shortcuts rear brake job.
Its a dirty nasty job but its not rocket surgery.
If you neglect the rear brakes, all of that stopping force transfers to the front brakes.
That not only cooks the rotors and calipers,
If the rears dont work, one day you will stomp on the brakes and the truck will ass swap you into a ditch or oncoming traffic.
Do a complete high quality stem to stern top to bottom brake job.
Its dirty and time consuming but its also the single best investment you can make for that truck.
Nothing else matters when its all sideways on the freeway

 

[thinger2]

Forgot to ask, Does a 95 have rear ABS?
If so that adds another layer to the problem