1964 brake bleed

[Jack J.]

[Edward J.]

[Mark E.]

Re: 1964 brake bleed

I've never tried bleeding brakes with a vacuum pump or Mighty-Vac so I can't speak to that.

Have you tried the old-fashioned two-man pump and bleed method?

I use a $50 "Power Bleeder" by Motive Products. In spite of its name, it's a hand pump (not powered) that enables me to easily bleed brakes by myself. Its instructions say to add brake fluid to the bottle, but it's easier and less messy to only pump air through the pump and keep the master cylinder full. It attaches to the top of the master cylinder and pressurizes it with the pump. Fluid streams out of the bleeders as they are opened.

[Frank D.]

Re: 1964 brake bleed

Never had ANY luck gravity bleeding my bone stock 63 power drum brakes. I did put speed bleeders at each wheel so I could do the one man manual bleeding and that works well. Crack the bleeder on a wheel, stroke the pedal about 4 times, close the bleeder, refill the master cylinder and move on to the next wheel.

[Jack J.]

Re: 1964 brake bleed

[Tom E.]

Re: 1964 brake bleed

I have both the mighty-vac and the Motive bleeder and neither impress me. The I bought this bleeder and that changed everything. Hooks up to your air compressor and vacuums the fluid out. When I restored my car I had all new lines, calipers and MC and it took about 20 minutes to bleed the entire car including the MC which I did not bench bleed prior to installing. Highly recommended and well worth the $85.
Tom

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[Larry M.]

Re: 1964 brake bleed

Jack:

Make sure you have the proper clearance between the end of the MC rod and the MC piston. It may vary a bit if you have PB or not, but there should be around a 1/32 inch to 1/16 inch clearance. If not, you could be partially restricting the fluid holes in the bottom of the master cylinder...........which could be an issue. The AIM and/or Chevrolet Service Manual has the exact clearance required and how to adjust. There is also a very neat and low cost gage for setting this dimension correctly. CSSB, Inc. sells one.........but Zip and others also offer them.

Personally I run DOT 5 in my 1967 car, but have recommended DOT 3/4 to friends that want "the sure thing" and no problems. If you do use DOT 5, I recommend getting recommendations regarding brand and source. I have old stock that I know works with no issues.

Larry

[Edward J.]

Re: 1964 brake bleed

Larry at some point the formula changed, I know many that used the dot5 about 7 or 8 years ago. But there have been many warnings about using it in our older cars.

[Larry M.]

Re: 1964 brake bleed

Larry at some point the formula changed, I know many that used the dot5 about 7 or 8 years ago. But there have been many warnings about using it in our older cars.

Ed:

A lot has been written about this in the archives. Agree something has changed, whether it is the DOT 5 fluid from SOME manufacturers, or if the Corvette caliper rebuilders are using a different. rubber material for the seals/orings. Parker O-ring Company states that they make and sell o-rings suitable for all DOT 5 fluid. They provide the part numbers in their catalog. They also say this o-ring will work for DOT 3/4 as well.

Parker is our leading o-ring supplier here in the USA and perhaps world-wide as well. Certainly during my lifetime......we used them exclusively in the chemical plants where I worked.


Larry

[Jack J.]

Re: 1964 brake bleed

Today I mentioned my problem/dilemma to a couple of car guys. The first, a retired GM engineer said BS on warnings about silicone. He said GM would use silicone, it being a better fluid, in all of their vehicles if it weren’t for the great possibility of contamination in the paint shop and that the military has been using silicone for years. The second guy didn’t seem to enthusiastic about my using silicone, mentioned calipers until I corrected him by saying my 64 has drum brakes all around. The GM guy suggested I remove the main line to the distribution block and see if I get gravity flow from MC thus narrowing my problem to the MC even though it was re-sleeved. Jack J.

[Larry M.]

Re: 1964 brake bleed

Sometimes the guys sleeving and rebuilding our MC can make a mistake..........and restrict the ports in the master cylinder. See Post 7.

Problems with the MC ports can result from rebuilding issues, or from improper clearance of the actuating rod during installation.

Larry

[Jack J.]

[Larry M.]

Re: 1964 brake bleed

Jack:

Just finished this job on a friend's 69. We added a power booster. Booster rod length was supposedly "correctly set" by rebuilder, but was too long and pushed in the MC piston(s) when installed.........covering the fluid holes. I could feel/see it, so I didn't need to go thru all the issues with fluid at this point.

I purchased the small tool needed to set the clearance as a gift to my friend, and then proceeded to make the adjustments. All is now okay.

Larry

[Jack J.]

[Jack J.]

Re: 1964 brake bleed

Larry, I just found/saw that procedure in my 64 supplement/figure 3. Emptied MC of brake fluid and it is off of the car. Both ports on bottom are either blocked (front port) by spring? or partially blocked (firewall port) by piston. Jack