truck hopping when on the brakes?

[benoit454]

Hey guys and girls, I got a uqestion for all of you.....

I have an 84 c10 all original as best I know.

it's had this hop to it ever since we got it, everytime you hit the brakes it sorta shimmies and shakes, or basically hops. Always seems to feel like it's coming from the back. My old man said if it's back brakes you feel them through the whole truck, and if it's front brakes you feel them in the steering wheel or pedal. he doesn't feel them on the wheel or pedal, just the whole truck hops. Sometimes it seems worse under slow brakeing or light pedal.

Well we checked it out, found the passenger side wheel cylinder busted, front shoes on both sides worn down way more then the rear most shoes. The driver's side front was worn past the top rivet.

So we put on ONE new passenger side wheel cylinder, had the drums turned, and bought new shoes. We figured that fix it but it didn't. it's not as bad, it used to pull you into traffic, but now it just hops, sometimes not as bad as before, others just as bad.

Another weird thing that happened was monday, memorial day, was when I done this, bled the rear lines, kept getting this spurt when I'd crack the new one loose, then a solid stream of fluid, no matter how many times I did it.

I do the two man job, one pumping, then holding, other taking bleeder loose, and tightening it when they hit the floor.

Well we got a good hard pedal, and left it alone. Started it up tuesday, moved it out of the carport, hit the brakes, pedal kept moving slowly down after hitting what I thought to be the hard spot and where they'd start working, truck kept rolling, pedal dropped very slowly to the floor.

So I tried re bleeding them today, same thing the new one kept spurting at first then a solid stream, the old one as soon as you cracked it loose it just be s solid stream out of it.

Pedal is better, but not full, maybe 3/4 or better.

Front brakes haven't been touched, pads are probably half gone maybe a little more. So I figure maybe that's the 3/4 pedal problem.

Any ideas on not having a full pedal?



The main question is the hop, why would it do it? Would it be my rotors bad? I'm going to have them turned and put on new pads, probably sometime soon. Right now we have to drive it, I got the interior out of my car dyeing it. So as soon as I get that finished I guess it'll be front brake time.

Any thoughts? would it be front brakes casuing the shaking/hop and not having full pedal?

Or maybe where I changed one wheel cylinder and not the other?


Or are they still seating and not fully seated yet? We did drive it today, maybe 10 miles round trip or little more.


Oh one other thing, I noticed on this truck is doesn't have the small canister in the power brake line. it's the one in the vacuum line going to the back of the carb. The 86 4x4 did, and my car does, as well as many others I've seen. yet my 86 camaro didn't and neither does this truck.