Front tires skidding

[joecal]

My front tires seem to be skidding when I brake a little harder on dry surfaces and more so on wet pavement. I thought maybe the front pads weren't releasing as they should, maybe they're not sliding on the pins. I checked the air pressure and that's okay. The tires look brand new but I noticed the date stamped on them say 07/11, so they are about 5 years old.They're Kumho tires and I bought the truck with them on it. Would older tires cause that because the rubber may be a little harder or could the brakes be locking up?
Any help is appreciated.

Joe

 

[chengny]

It isn't likely a tire issue. If the tread depth is good, that would reduce the tendency to skid. Skidding when braking - if the problem is tire related - becomes more pronounced as tread depth decreases.

It might seem counter-intuitive, but the problem my be related to the rear brakes rather than the fronts.

Inspect rear brake operation and adjustment. Rear brakes which are out of adjustment will require the front brakes to provide a greater amount of the total braking force. When you brake heavily - and the rears are not doing their share of the load - more pressure is applied to the fronts (by you - as you try to slow the truck). So, rather than all four tires slowing the truck, the fronts are applied until they lock up and skid.

It's kind of like the opposite concept of how 4WD increases traction (as opposed to 2WD). The driving force is distributed among all 4 wheels and that helps prevent the tires from slipping.

Not saying this is definitely the problem, but if everything looks good on the front/disc brakes, check the rear/drums.

 

[joecal]

It isn't likely a tire issue. If the tread depth is good, that would reduce the tendency to skid. Skidding when braking - if the problem is tire related - becomes more pronounced as tread depth decreases.

It might seem counter-intuitive, but the problem my be related to the rear brakes rather than the fronts.

Inspect rear brake operation and adjustment. Rear brakes which are out of adjustment will require the front brakes to provide a greater amount of the total braking force. When you brake heavily - and the rears are not doing their share of the load - more pressure is applied to the fronts (by you - as you try to slow the truck). So, rather than all four tires slowing the truck, the fronts are applied until they lock up and skid.

Not saying this is definitely the problem, but if everything looks good on the front/disc brakes, check the rear/drums.

Thanks for the information, I haven't looked at the rear brakes yet. I've only had the truck a few months so I'm still trying to sort things out when the weather allows. I did notice the brake fluid looks very old or dirty, I definitely need to change that, maybe there's water in there.
Thanks again!

 

[joecal]

It isn't likely a tire issue. If the tread depth is good, that would reduce the tendency to skid. Skidding when braking - if the problem is tire related - becomes more pronounced as tread depth decreases.

It might seem counter-intuitive, but the problem my be related to the rear brakes rather than the fronts.

Inspect rear brake operation and adjustment. Rear brakes which are out of adjustment will require the front brakes to provide a greater amount of the total braking force. When you brake heavily - and the rears are not doing their share of the load - more pressure is applied to the fronts (by you - as you try to slow the truck). So, rather than all four tires slowing the truck, the fronts are applied until they lock up and skid.

Not saying this is definitely the problem, but if everything looks good on the front/disc brakes, check the rear/drums.

Thanks for the information, I haven't looked at the rear brakes yet. I've only had the truck a few months so I'm still trying to sort things out when the weather allows. I did notice the brake fluid looks very old or dirty, I definitely need to change that, maybe there's water in there.
Thanks again!

 

[joecal]

Thanks again chengny, I think you were right about the problem being with the rear brakes. I noticed a crushed rear brake line on the passenger side and replaced that thinking the wheel cylinder wasn't getting enough fluid. That didn't change anything, today I pulled off the brake drum on that side and the shoes are pretty worn. I'm going to replace them when I get the parts but I'm pretty sure that's the problem. I held the brake pedal down and both rear tires still moved with a little resistance but not much.