67' Country Squire Brakes Question

Hi all, I have a 1967 Country Squire Wagon, (Was my uncles he passed away so I bought it from his wife).

It's a 390 car with factory four piston disc brakes up front (drums in the rear). I over the past few weekends have been working on replacing all of the brake parts front to back. New Drums/shoes, New rotors, new calipers, and a new master cylinder(didn't think at the time that I should have pulled the booster out too). Thus comes potentially my question.

Today was the day, I finished the last of the brake lines everything attached and good to go. My dad and I bled them front to back. F.Drivers, F.Passenger, R.Driver, and R.Passenger. Got all of the air out.. (at least fairly confident).

We set the car on the ground and backed it out, the car wouldn't hardly stop. As hard/far as I could push on the pedal could basically just get it to slow down (and eventually a stop).
Could this be the doings of a bad brake booster? All of my other classic iron is manual brakes so this is definitely my first rodeo in this realm. Looking for some tips/tricks! Thanks much!!


TLR. Replaced entire brake system (except booster) and the brakes suck.

 

When you say the brakes were not stopping the car, do you mean the pedal was very stiff, not much travel? Or that there was good travel, down to within 2" of the floor, but the car refused to slow down in a quick manner? Did you attempt a hard braking to see if the brakes would lock the wheels up?

 

I think you bled backwards and still have air .

 

@Silvertwinkiehobo The pedal was pretty stiff still most definitely. Travel wise, I could get it within 2" of the floor but it was a have both feet on the pedal and push type situation. I attempted a hard brake a few different times and it wouldn't lock them up.
@63Fowagon What do you mean by bled backwards?

 

This is strange, since the booster is primarily there for the disk brakes. Drum brakes don't necessarily need a booster. It's the proportioning valve which devides the load, on most cars. If there was any air, in the lines, the pedal would be spongy. You fail to mention how the vehicle's brakes performed, before you went ahead and changed all those parts. If it braked at all, I'd suspect the master cylinder to have been improperly assembled or built. Especially, if it's a re-build or made in a 3rd World country. The more parts you unnecessarily replace, the more likely you're likely to get into such situations.

 

Fair enough.
So when I acquired the car, there was no brakes in it what so-ever. the front lines were rotted and the front calipers all pistons were froze. The car had sat in the weeds for some years prior to me getting a hold of it. That's primarily what started me down this path. Trust me.. If I didn't need to replace all the stuff I did, I most certainly wouldn't have.. Running brake lines on a land-yacht was less than fun hahaha

 

Okay. Sorry for being suspicious. Alot of people just replace stuff, without even appraising the parts that are already on their vehicles. Often times, original parts are much better than what's being manufactured aftermarket.
If you test the booster and find out it's functioning properly, you could at least rule it out as a probable cause. It's a simple device which could be simply tested. If the diaphragm is hermetic, the adjustment might be off. There's always a remote possibility that a previous owner tinkered with the adjustment, not knowing that the diaphragm was either punctured or not sealing. Outside appearance isn't always a unit of measurement for judging a booster. When you take a rusty greasy one apart, the innards often look brand new:

https://www.youtube.com/results?search_query=power+brake+vacuum+booster+test

A Datsun booster is basically no different than any other:

 

R/R ,L/R ,R/F ,L/F Always farthest point from master cylinder on these older autos .

 

INTERESTING!!!! Never knew that!!! Any suggestions for bleeding tools? We just did the standard someone in the car someone at the bleed valves opening/closing. I'd like to get something to try and make the job a bit easier while I'm there.

Thanks for the ideas so far guys!!!

 

That's interesting. How to bleed brakes, in order to counter a hard pedal.

 

? huh?

 

Didn't you just tell us that you and your dad bled the brakes, already?
Are you getting vacuum to the booster. Do you hear a hiss, when you step on the brake pedal?
If not, the check valve or rubber seal could be at fault:

 

Yeah, if you had to put both feet on the pedal to get it to go full-stroke, it's not boosting. One quick (but not 100% accurate) test is to start and run the engine up to temp, verify choke is open, then squeese the booster vacuum hose closed with pliers. If the engine speed changes considerably, you have a booster leak. It could be the internal diaphragm, or it could be the sealing disk around the pushrod. If it does it, you can unbolt and move aside the master cylinder (don't undo the hydraulic lines or kink them when moving the master cylinder out of the way), then pull the pushrod out, which will pull the rubber disc with it. clean the front housing of any rust or dirt, then pull the pushrod out and clean the shaft where the disc normally rides. lube with some silicone dielectric grease. Inspect the disc, ensuring the rubber has not rotted or torn. Reassemble the rod and disc into the booster housing. Reattach the master cylinder to the housing.

 

Did you bench bleed master cylinder ? No mention of the rubber lines that can cause major problems . Rear brakes properly adjusted ? There is also an adjustment on booster pushrod . With power brakes of this era the car should still stop with just a little extra effort on pedal and even lock-up wheels . Don't overthink this is still a basic hydraulic system with a booster to make less pedal effort but doesn't make any more pressure in the system .

 

Awesome. Some more things to try when I get back up there Thursday evening. Thanks for all the tips guys. I'll definitely report back our findings!!!