Rear Wheel Hop While Braking (Update)

[1-ton]

I am recently getting some rear wheel hop while braking (1991 Chevy V3500 Crew Cab). I ran into this guy that has a square body like mine. He said he had the same problem once too, and a new rear rubber brake line fixed it. I did replace the rear rubber brake line once, but that was about 15-years and 50-60,000 miles ago.

Before anybody has any other suggestion, it is time to write the usual novel of new parts already replaced (not because of wheel the hop though).

1. shoes
2. brake harware
3. wheel cylinders
4. drums
5. axle bearings
6. axle seals

 

[Bent77]

Was curious if the brakes might be too tight

 

[ChrisPerry]

Check the rear ubolts.

 

[tRustyK5]

I'd pull the drums and look for leaks that may be contaminating the shoes...which would possibly lead to grabby brakes. Too loosely adjusted can also do the same thing, so double checking the adjusters aren't frozen would also be a good idea.

 

[1-ton]

I am going to try replacing that rubber brake hose first, and if that does not do it, I will take the rear drums off to look into some of the things mentioned.

 

[imiceman44]

I am recently getting some rear wheel hop while braking (1991 Chevy V3500 Crew Cab). I ran into this guy that has a square body like mine. He said he had the same problem once too, and a new rear rubber brake line fixed it. I did replace the rear rubber brake line once, but that was about 15-years and 50-60,000 miles ago.

Before anybody has any other suggestion, it is time to write the usual novel of new parts already replaced (not because of wheel the hop though).

1. shoes
2. brake harware
3. wheel cylinders
4. drums
5. axle bearings
6. axle seals

One thing no one mentioned, bad shocks can also do this

 

[diesel4me]

Agreed on the bad shocks...that can do it..and the contaminated linings too...

Also make sure the brake shoes are installed right--smaller lining facing the front of the truck...having one side or both wrong can lead to issues like that...(dont ask!)..

I hate brake problems almost as much as electrical ones..both suck to diagnose,and usually can be "fixed" in 5 minutes..


I checked my master cylinder level a week ago--the rear chamber was empty!..I've had a "lack of power assist" issue suddenly appear during a severe cold snap about 2 months ago,but the fluid level was perfect then,so I do not think its related--I traced the "leak" to the drivers side wheel cylinder,fluid is oozing out of the drum onto the tire..I replaced both rear wheel cylinders a few years ago too,they might have 3000 miles on them !...Autozone ones, $9.99 each--I guess I'll be seeing how their "lifetime warranty" pans out..

I filled the master cylinder up that day--so far its only dropped about 3/8" or so...which is weird,I'd think it would go dry in a day of use,but I've driven it over 100 miles....

 

[obijuank5]

Believe it or not, warped front rotors made my truck hop in the rear. Replaced em and boom. Fixed.

 

[1-ton]

I fixed most of the wheel hopping by removing the Load Sensing Proportioning Valve in the rear. I just got a fitting that joined the two brake line pieces together, thus eliminating the brake valve. I still have a small amount of wheel hop, but not nearly as bad as it was.