Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Power brakes dont feel right...any suggestions?
View Single Post
  #31 (permalink)  
Old 01-20-2013, 06:01 PM
aosborn's Avatar
aosborn aosborn is offline
Registered User
 
Last wiki edit: Suspension: designs, shapes, sizes Last photo:
Join Date: Oct 2008
Location: Lakewood, WA
Posts: 621
Wiki Edits: 7

Thanks: 0
Thanked 17 Times in 16 Posts
Hers's the deal...Typically a kit purchased for a disc/drum combo will come with a 1 1/8" master cylinder as you don't need as much line pressure with that combo.

If the kit came with a combination valve it will be incorrect with a disc/disc system because of the 10lb residual pressure valve going to the rear brakes and the metering portion will be wrong. It sounds like you had a stand-alone residual pressure valve, and in that case you should have switched the 10lb for a 2lb. The 2lb check valve keeps the pads from backing away from the rotor when you are not pressing the brake pedal. Also make sure they are installed in the proper direction.

With your booster, a 1" bore master cylinder with a 2lb check valve in the line to the front brakes and another in the line to the rear brakes along with an adjustable proportioning valve, (or the proper combination valve) will give you good brake action. I will assume that you haven' modified the brake pedal assembly as it came from the manufacturer.

Does the master cylinder you are using have a deep (about 1") depression in the rear of the piston, or a shallow one (about 1/4")? In most cases you need the shallow one with a power brake booster. Again, a photo showing the unit and the piston would be most helpful.

Lastly, what type of calipers are you using on the rear?

If we beat on this long enough it will eventually give in and work for you!

Andy
Reply With Quote