Change brake push rod?
- Thread starter OLDFART
- Start date
Definitely should not be a need for a different rod.
The master you got should have two small round "humps" in the cap, right?
Did you plumb it correctly? The front hole goes to the front brakes, the rear to the rear. Also try bleeding it again. Did you bench bleed master prior to installation?
You didn't change the length of the rod by screwing the clevis in or out, did you?
The master you got should have two small round "humps" in the cap, right?
Did you plumb it correctly? The front hole goes to the front brakes, the rear to the rear. Also try bleeding it again. Did you bench bleed master prior to installation?
You didn't change the length of the rod by screwing the clevis in or out, did you?
OLDFART
Member
I was told that the front hole goes to the back lines and the back hole is for the front brakes..was I told the wrong thing??If so,they are hooked up backwards.
That's why I need to know which master, by looks. All the Chevy masters I use, and I only use Chevy masters the front hole is the front brakes. What size are the fittings on the front and rear holes? They should be 1/2 front and 9/16 rear hole.
I'm going to assume that you've already tried all the easy stuff...bleeding, etc etc. Not all 68 Impalas had the same kind of brakes. Mine (327 automatic) had 4 wheel drums w/power assist. My friend's girlfriend had one with front power disc (327 automatic) . You may have acquired a master cylinder that isn't correct for your set-up. Or...heaven help...it's a faulty unit. I had a similar situation recently with a 57 Bel Air. Someone previous had converted it to front disc brakes with a new master cylinder. The complaint my customer had was that it felt like the rears were doing all the stopping. He was right (some customers are). My solution was to order a complete unit, consisting of a master cylinder and a 9 inch booster from an outfit in Indiana. Now mind you, it did not have power brakes before this, but the customer asked if converting it would be a problem. Nope, I said. So in my case, the fix was actually easy. Anyway, it sounds like a compatability issue to me. 
I really want to change my master cylinder to a dual unit for drum brakes. Will the 1968 dual master be a bolt on with only changing the plumbing. I don't want power brakes because the next cam I buy I don't want any engine vacuum.
Roy
Roy
Bolt on
Roy, I replaced my single master cylinder with one from a late 60s drum-drum setup (1968 or 1969?) and had the same problem as mentioned in this thread. Adjusted and bled and adjusted and bled, fronts still feel a bit weak compared to the back brakes.
I put a proportioning valve in place, not much effect. I did acquire a "more correct" dual master cylinder from a reputable Chevy parts source, haven't fit it up as yet (my brakes aren't THAT bad...).
Basically I plugged the front fourway and ran one line to the front, one to the back. Had to mess around with various adapters to get get the lines to fit up. Depends on the fittings used to connect to the master.
Hope that helps some, it's pretty much a bolt on deal with a little fussing over connections
.
Cheers!
TomK
Roy, I replaced my single master cylinder with one from a late 60s drum-drum setup (1968 or 1969?) and had the same problem as mentioned in this thread. Adjusted and bled and adjusted and bled, fronts still feel a bit weak compared to the back brakes.
I put a proportioning valve in place, not much effect. I did acquire a "more correct" dual master cylinder from a reputable Chevy parts source, haven't fit it up as yet (my brakes aren't THAT bad...).
Basically I plugged the front fourway and ran one line to the front, one to the back. Had to mess around with various adapters to get get the lines to fit up. Depends on the fittings used to connect to the master.
Hope that helps some, it's pretty much a bolt on deal with a little fussing over connections
.Cheers!
TomK
Here's a good photo reference showing which port is the front & rear on a variety of master cylinders.
http://www.mpbrakes.com/uploads/documents/mcplumbingpdf.pdf
http://www.mpbrakes.com/uploads/documents/mcplumbingpdf.pdf
I really want to change my master cylinder to a dual unit for drum brakes. Will the 1968 dual master be a bolt on with only changing the plumbing. I don't want power brakes because the next cam I buy I don't want any engine vacuum.
You must be kidding!
That would be one BIG cam !!!!
I have no problems with vacc with my engine /cam combo,,dq
That would be one BIG cam !!!!
I have no problems with vacc with my engine /cam combo,,dq
I doubt that he is kidding. Even small aftermarket grinds reduce the vacumm level quite significantly. The centerline is a big factor in determining this. A small, say 210@50 ground on 110-112 will knock off 4-5 inches of vac. Most GM grinds were on 114.