1980 c10 good brakes but will not s

[80chevybeater]

I got my truck at auction for $100.00 not special 250 inline 3 spd manual brakes power steering mo A/C. Was using as farm truck do to Exhaust leak at manifold. I fix that and had truck pass inspection.

The other day I was driving in the rain for the first time. I came to stop the truck did a 180. What fun . Luckly, it was in a rural road and no traffic was around. That same day I loaded the truck with 40 cubic feet of garden soil As I came down a hill and tried to stop the tires kept locking up and I would just slide. It was like I was on ice. (it was raining still)I could not stop. I just ran the intersection. Again on rural road no one around.

Is it common for the rear brakes to lock-up. Or is it that the tire are just not good in rain. It has M$S LT radial have lots of tread depth. The truck runs fine on dry days.

what do you guys think? tires or brakes will a power brake conversion help? How about traction bars?

I was only going like 40 mph I hate to think I will have to drive like grandma when it rains or just sit it out.

 

[MarkyB]

RE: 1980 c10 good brakes but will n

Sounds like you may have rear wheel cylinder leakage. Once the o-rings or metal, inside wheel cylinders wear, you will have brake fluid seep around the dust boots. This brake fluid ends up making its way to the brake shoes, which in turn causes the shoes to "grab" the drums and results in the brakes locking up. Pull the rear drums off, and look for wetness around the brake hardware, backplate, and on the shoes. It will be obvious. It will be charcoal black in color and look "caked" on rather than "dusty." If you find leakage, you will need to replace or rebuild the cylinder, clean the hardware and backplate of any fluid residue, and replace the shoes. Once the fluid absorbs into the shoes, you can't get it out. Even if you replace the faulty wheel cylinder and not the shoes, the shoes will still grab the drums because of the fluid absorbed into them. If you don't remove the fluid residue when replacing the shoes, you may end up with the same problem again because the shoes contact the backplate and will absorb the fluid again. If this doesn't solve your problem, you may have a bad proportioning valve. This problem wouldn't justify any type of conversion to power brakes, unless you just wanted to. The power brakes will do the exact same thing. I've done the 180's several times with power brakes...I actually think it's easier to do a 180 with power brakes. Hope this helps.

 

[nsula_country]

RE: 1980 c10 good brakes but will n

I agree with MarkyB. Fluid seepage will cause grabby brakes as will a proportioning valve malfunction. Roughly 70% of braking power is supposed to be diverted to the front wheels. One other thing could be a brake line collapsing and causing one wheel to lock, causing an arcing skid (180). My truck has the HD power brake package, JH8 I think and wet roads are a nightmare. The brakes are overly powerful (13" drums), I have lost it a few times before I learned how sensitive they are. Manual brakes are fine for a half-ton truck, it just takes more pressure at the pedal. Good luck.

79 C20 Bonanza
350/400 4bbl Q-Jet
3.73 14-Bolt Corp.

 

[FI84GMC]

RE: 1980 c10 good brakes but will n

In addition to 80chevybeaters response, it could be a leaking axle seal, which would cause the same issue with the contamination of the brake shoes.

Brian
Show Low, Az