I have a 1967 Chevrolet Camaro with manual drum brakes on all 4 wheels. No power assist. Standard transmission with 250 cu in 6 cylinder engine. Approximately 101200 miles. Problem: Brake pedal goes next to floor before getting some braking action on rears and no action on the fronts. Have replaced the master cylinder several times with different well known auto supply store new units. New lines. New brake wheel cylinders installed several times on all wheels. New brake pipe distribution block/switch assembly (brake safety switch is located in this block). Bled the master on each installation. Lines bled good and confirmed with Monroe store that they were free of air and who just scratched there heads on this one. New shoes (up-grades to Bendix). Have double checked the clevis pin location to make sure it is in the right hole in the pedal assembly. Have checked several times to make sure the rod is seated in the deep socket master cylinder and that I have 1/16 to 1/4 inch free play as the spec call for. Dash brake light is on indicating there is a pressure imbalance in the system but I can't find it.
That is a good one. I take it the shoes are adjusted properly? Check the pin under the rubber boot on the side of the proportioning valve to see if maybe it is stuck all the way one direction, could have happened during brake bleeding.
October, 29, 2007 AT 6:19 PM
Thanks for the response. There isn't a proportioning valve on this car. Yes, the shoes have been adjusted out to where there is a slight drag on the drum with rotation.
October, 30, 2007 AT 7:37 AM
Sounds like the master is by-passing the fronts, is the rod the original one? When bleeding using th epedal, does fluid shoot from the bleeder or just dribble out? BTW 1st Gen Camaros are the best ones, had a 68 myself
October, 30, 2007 AT 11:42 AM
Yes, the rod is original. I get a good stream of fluid. Bet you wish you still had that 68 : )
October, 30, 2007 AT 1:01 PM
Sure do, but my driving record thanks me. LOL. Can I ask why you are messing with drums instead of installing power disc. Brake hoses are new? Does it push fluid out if you loosen the hard line for the front at the master cyl?
October, 30, 2007 AT 4:03 PM
It's my son's car and neither of us has the money right now to upgrade. Have to find the problem with the brakes we have. All new hoses. Have taken line loose at at all connections to see what kind of flow I get and to bleed lines. It is good at all points. The master pushes fluid. The problem is the pedal goes all the way to the floor and the front brakes don't move enough to provide any braking action even though they are adjusted out to a slight drag with no pedal applied.
October, 30, 2007 AT 4:22 PM
The block you spoke of before might be the problem. If it has hydraulic pressure at the wheels, the brakes should work. Try using unions and by-passing the junction block and see what happens. BTW did you bench bleed the master cyl?
October, 30, 2007 AT 7:23 PM
The block is new. Yes, I bench bled the mc before installation. The brake light switch is also located in this distribution block. The switch, as you most likely know, is activated when it sees higher pressure on one side. The dash brake light is on and I believe it is giving a reliable indication that there is a problem on the front side since the shoes don't hardly move except when the pedal is almost to the floor. And I mean almost to the floor. I have checked and re-checked things so many times that I've lost count. Still, I must be over looking something!
October, 31, 2007 AT 7:27 AM
Is it hooked up properly? Could have a shuttle valve in it that is stuck to one side. Try slamming th ebrake pedal hard with your foot, have seen this re-center valves before. Worth a go
October, 31, 2007 AT 3:52 PM
Yep, it's connected as per assembly manual and service manual instructions. I tried your " slamming" technique several times but it had no effect. Any more ideas?