brake question

[reborn55]

Wife's delivery---48 Chevy with 74 Nova clip--checking stuff, and found pinched r/r brake line--replace rear lines, rear hose and wheel cylinders---took for a test drive--could only get r/r to lock up and little pull/dart to right--put new calipers and hoses on--bled brakes--stop Ok but still only r/r locks up on panic stop--just don't feel right--thinking it may be master cylinder time also. Everything bled fine, but pedal was weak the first time through--had to re-bleed rear brakes. Looks like it has a master cylinder booster from a 77 corvette(casting number5480348--crosses to a Corvette)..Question should I stay with the same type master cylinder as the one on there or opt for 74 Nova with disc/drum they are different. Getting ready for Hot Rod Reunion and wife will be doing brunt of driving--old age has finally caught up with me and back/hip is feeling poorly. THANKS

[unklian]

Is the LR wheel cyl free ?

[wayne petty]

are the tire sizes the same..

are the drums both machined to the same surface finish..

are the brake shoes on in the proper direction.. short lining toward the front of the car..

how are the rear brakes adjusted.. climb under and stick a screwdriver and a shine a flashlight into the adjuster slot..  lever the start wheel sideways toward the front of the car.. NOT ROTATING IT..  then lever it to the rear of the car..  how far did the bottom of the star wheel move side to side..  if you find it moves more than about 1/8"  you need to adjust the brakes..

please look at the part numbers from the wheel cylinders.. there are multiple sizes of wheel cylinders available..  and that is how manufactures still adjust brake bias..   could you have the different sizes because somebody at the store swapped boxes??? absolutely..  could they have pulled one wheel cylinder for one app and the other for another app.. i have found a bunch of cars like that..

say.. with the circle track guys all running metric rear ends.. and not be getting enough rear braking.. i even found one application of the snap ring retained metric wheel cylinders with 7/8 instead of 3/4"..

please also check that your axle bearings are NOT worn.. brake drum off..  lift axle shaft while looking behind it at the seal face.. the axle should NOT LIFT AT ALL .. if it does..  go up and down in the bearing.. the rear axle will not be equally centered in the drum and shoes..  this will cause havoc...

are the brake backing plate bolts tightly fastened.  so they are not rocking..

are the wheel cylinders tightly fastened to the backing plate??

this are just things i am asking as you are on the far side of the country and i cannot see your rear axle from here.   even when i stand on my toes..  say.. is that a gator in your pool..  or just an inflatable version that could raise a lot of fun..  partially filled with water to keep most of it below the surface..

[reborn55]

Wayne
Tires are same size

Drums machine the same

Shoes are on correctly

No adjustment holes in the backing plate or drums--adjusted by feel as best as I could then back up the car applying the brakes to activate self adjusters


wheel cylinder are new and correct as with rubber bake line and metal lines

Rear end has been redone with all new bearings and seals etc.  

thanks for all the info--have a great day

[unklian]

are the brake shoes on in the proper direction.. short lining toward the front of the car..



please look at the part numbers from the wheel cylinders.. there are multiple sizes of wheel cylinders available..  and that is how manufactures still adjust brake bias..   could you have the different sizes because somebody at the store swapped boxes??? absolutely..  could they have pulled one wheel cylinder for one app and the other for another app.. i have found a bunch of cars like that..

good ideas.

[enjenjo]

Wayne
Tires are same size

Drums machine the same

Shoes are on correctly

No adjustment holes in the backing plate or drums--adjusted by feel as best as I could then back up the car applying the brakes to activate self adjusters


wheel cylinder are new and correct as with rubber bake line and metal lines

Rear end has been redone with all new bearings and seals etc.  

thanks for all the info--have a great day

One drum contaminated with oil, or grease, or brake fluid?

[UGLY OLDS]

Make SURE  the parking brake cables are backed completely off before adjusting the brakes at each wheel ...The parking brake adjustment is the LAST thing to do when adjusting drum brakes .....


Bob .....

[reborn55]

Pulled it all apart today and found one shoe with a loose rivet and another with a small crack--new shoes tomorrow---and we will see what ahppens---Thanks