1964 best brake bleeding procedure?

[Tim D.]

I have a 64 with drum brakes. During my frame off, I replaced every part of the brake system top to bottom including the PB booster, master cylinder, brake lines, blocks, wheel cylinders, brake shoes, springs etc. with correct "original style" parts. After reading many archives, I have decided to stick with GM/Delco Supreme II, dot 3. However, I am still a little unsure of the exact bleeding procedure. It seems that everyone has their own method.

Given the fact that the entire system is empty and has never had any fluid in it, what is the best procedure to fill the system (and keep it full) and bleed the brakes? I will be doing this manually with a helper. The master cylinder is already mounted in the car and I did not previously bench bleed it. The car is currently on car skates. I am assuming I will have to put it on jack stands and remove the wheels. I purchased an off set brake bleeding wrench and several feet of clear tubing. I also have four clear plastic gallon milk jugs that are super clean and dry.

Any thoughts would be appreciated. Since this is my first restoration, every step is a new learning experience for me.

Thanks in advance.
Tim

[Jim T.]

Re: 1964 best brake bleeding procedure?

First thing I recommend is to remove the master cylinder and do the bench bleeding.
After bench bleeding the master cylinder let gravity work. Close all but the farthest rear wheel cylinder bleeder valve from the master cylinder and let gravity pull the fluid to this cylinder with out pumping the brake pedal and then close the bleeder valve. Open the other rear bleeder valve and do the same and after this rear cylinder is flowing close it.
Open the front bleeder valve farthest from the master cylinder and then close it when the fluid is flowing and do the other front and close it.
During the gravity process do not lot the master cylinder run out of fluid, I would not let it get more than half way empty.
Once all four have gravity bled, check the pedal to see what you have. Now you can use a helper to pump while you bleed each bleeder valve starting at the first rear one you bled by gravity and do the others in the above order.
Keep fluid in the master cylinder. If you do not see any air bubbles in the line bleeding with your helper pumping, you did a good gravity bleed.

[Tim D.]

Re: 1964 best brake bleeding procedure?

Jim, thank you very much for the clear, in depth explaination. I understand everything you suggested. However, could you please explain the exact method/steps to bench bleeding the master cylinder? Also, what are the precautions I must take to reinstall the master cylinder when it is full and bench bled so as to not get any brake fluid on my new paint etc. When I am performing the gravity bleed sequence and then while performing the pedal pump sequence, should the master cylinder cap be off, on tight and secured with bail or just sitting loose on top of the MC? Thanks, Tim

[Jim T.]

Re: 1964 best brake bleeding procedure?

Your master cylinder does not have to be completely full to bench bleed. I use a vise to hold the master cylinder at an angle, front down. Protect your new master cylinder from vise clamping with something of your choice.
I have a kit that can be bought at an auto parts store that attaches to the outlet of the master cylinder with a hose that routes the expelled fluid back into the the master with the tip submerger in the masters fluid to verify all air is out of the master cylinder.
Protect the paint if doing this close to any car, accidents happen. Protect the paint when installing the master, protect the paint when bleeding.
Gravity bleeding I would not install the cap securely, just cover the fluid. A secured cap could lessen the gravity flow. DOT3-4 type brake fluid is hydoscopic, it absorbs moisture. Open master cylinders allow this.
I would secure the cap for pumping the brakes and refill after each wheel cylinder bleed if necessary depending on amount of fluid bled.

[Tim D.]

Re: 1964 best brake bleeding procedure?

Hi Jim. Thanks for taking the time to reply again. I am going to take your advice and remove the MC from the car and bench bleed it first in the mannor you described above. I really appreciate you walking me through the entire brake bleeding procedure. You really clarified it for me. I felt like I knew just enough to be dangerous (literally). I will post another thread when I have completed bleeding the system. I am getting very excited. After a LONG restoration, I am planning on starting the car and bleeding the brakes this coming week. Can't wait! Thanks again, Tim

[John H.]

Re: 1964 best brake bleeding procedure?

Tim -

Gravity bleeding can take a LONG time, and if you don't keep a constant check on the master cylinder and it runs dry, you get to start all over again. As an alternative, I prefer the Motive Products (www.motiveproducts.com) pressure bleeder; makes it a one-person ten-minute job every time, and you don't have to watch the master cylinder.

[Michael G.]

Re: 1964 best brake bleeding procedure?

Jim,

What does this rig cost? Heard about these....never used one. Like the idea.

[Larry M.]

Re: 1964 best brake bleeding procedure?

Jim,

What does this rig cost? Heard about these....never used one. Like the idea.

www.motiveproducts.com About $70 for the one shown in John's picture.

Larry

[Tim D.]

Re: 1964 best brake bleeding procedure?

Jim, John, Michael and Larry,
Thanks to all of you for your expert advice. I filled the entire brake system Saturday. As I mentioned on my first post, this is a complete restoration so the entire system was bone dry. After talking with my friend, Steve who works on fighter jets for Boeing, I filled the system with a medical syringe from the bottom bleeder valves starting with the right rear and proceding to left rear, right front, left front. By doing this, it allowed the air bubbles to rise as they naturally want to do. He injected the fluid from below while I watched the master cylinder to see when the fluid began to fill. I was going to use another syringe the draw fluid from the master cylinder to keep it from overflowing. However, the master cylinder never allowed fluid in and Steve began to feel back pressure from his end. Therefore, we figured all lines were full and there may be a blockage of some kind in the master cylinder. After slightly pumping the brake pedal and watching the piston, we pulled the line loose at mc and sure enough, the fluid was right there but something was keeping it from filling into the mc. I checked my shop manual and we decided to pull the mc and put it on the bench. We inserted a sewing needle into the compensating port and it was in fact slightly clogged with ? We reemed the needle in and out several times which opened the clog. Then we held a paper towel over the top of the mc (pointed it way away from the car) and blew compressed air into the mc which seemed to spew some atomized brake fluid (or something) into the air (paper towel). We think it was probably the braked fluid that was used during assemby of the mc. At any rate, this seemed to solve the clogged problem. Then we decided to reinstall the mc on power brake booster and fill it from the top. After that, we simply started at the right rear and did the two man pump, hold, bleed procedure following the sequence RR, LR, RF, LF and then MC. We did this about 3-4 times around the car, keeping an eye on the mc fluid level and refilling as necessary. Within no time, the air was completely eliminated. The car has a great pedal now and it won't be long before I take it on it's maiden voyage around the cul-de-sac in front of my house. Once again, I really appreciate everyone's help and advice. Tim

[John H.]

Re: 1964 best brake bleeding procedure?

Tim -

Good job! Thanks for the update.

[Michael G.]

Re: 1964 best brake bleeding procedure?

Sweet......these happy endings always make me cry...