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I changed the manual brake master cylinder on my 68 convert and thought I would save a couple $$ (actually almost $100) by buying an aftermarket part at Advance Auto. Their replacement part made by Cardone does not have the bleeder valves like the GM replacement master cylinder. While bench bleeding the master cylinder the rear reservoir and rear circuit seemed to really be difficult to get all of the air out and the volume of fluid pumped was considerably less than the front circuit. Anyone else notice this? When installed on the car, the brake feel is not as firm as should be, despite getting all of the air out of the lines to the individual calipers. I have the GM part ordered and will take the cheap part off and remember sometimes you get what you pay for.
Your bench bleeding procedure should include tipping the MC up, down & level for several strokes in each position. I suspect there is a bubble still trapped in there.
Take a look at my profile and then photo album: brake bleeding for reference.
And CAUTION. Do Not Force your screwdriver & MC piston in farther than 1 3/8" or you will damage the seals, void the warranty.
C3s are kind of picky when it comes to proper brake parts. I would stick to a known Vette vendor instead of over-the-counter parts. Try Willcox, Zip or Keen for a MC.
My aftermarket master cylinder works just fine. The big difference I found was to use a pressure bleeder instead of trying to do it all manually. I kept blaming my master cylinder but it was really my calipers. I ended up installing Wilwoods about 6.5 years ago and haven't had a problem since.
Your bench bleeding procedure should include tipping the MC up, down & level for several strokes in each position. I suspect there is a bubble still trapped in there.
Take a look at my profile and then photo album: brake bleeding for reference.
And CAUTION. Do Not Force your screwdriver & MC piston in farther than 1 3/8" or you will damage the seals, void the warranty.
C3s are kind of picky when it comes to proper brake parts. I would stick to a known Vette vendor instead of over-the-counter parts. Try Willcox, Zip or Keen for a MC.
Thanks. I rarely use anything except parts from Eckler's or Paragon, but tried to be cheap this time. I also suspect there is still air in the MC, I pumped the thing for at least ten minute and tilted it while tapping with a hammer to dislodge any bubbles caught in any rough places in the casting. I have done this dozens of times and this is the first time it was so difficult. I do not have a pressure bleeder, but now will buy one just so I do not go thru this frustration again.
Last edited by ronarndt; 02-27-2019 at 09:48 AM.
Reason: typo
Good call on getting the pressure bleeder. I’d suggest Motive but there are others. Once you use it, you’ll be ticked that you hadn’t bought one sooner.
Last edited by CA-Legal-Vette; 02-27-2019 at 10:02 AM.
You may have some luck with buying a used Motive Pressure Bleeder on eBay a lot cheaper. You will have to make your own MC lid adaptor and usually have to put new hoses on the tank. Some people buy them and only use them once, then sell it.
You may have some luck with buying a used Motive Pressure Bleeder on eBay a lot cheaper. You will have to make your own MC lid adaptor and usually have to put new hoses on the tank. Some people buy them and only use them once, then sell it.
I have a spare MC cover that I will braze a fitting onto it. I have read others having trouble getting the generic cover with the little chains to seal properly. I should have done this years ago.
I have a spare MC cover that I will braze a fitting onto it. I have read others having trouble getting the generic cover with the little chains to seal properly. I should have done this years ago.
That idea will work too. As far as the lid adaptor with chains, what a joke. Pitch it in the office round file.
You only need about 8-12 lbs of air pressure to get the bleeder screws flowing. Put some towels under the MC, over the MC and on the fenders. Brake fluid hates paint.
Don't let the MC or the tank run empty.
I like to see what's going on in the MC while its being pressurized and fluid is being added. So I made a thick plexiglass MC lid plate that gets a giant "C" clamped on.
A photo is shown in my profile photo album.
you`re living in dreamland if you think you are buying a new genuine GM/Delco-Moraine master cylinder from anyone, they are all aftermarket.
Well of course parts for a 50 year old car are aftermarket. GM restoration parts, which is what I ordered, are as close to the original as you can get and will be better than the ones from the auto chain stores..
Well of course parts for a 50 year old car are aftermarket. GM restoration parts, which is what I ordered, are as close to the original as you can get and will be better than the ones from the auto chain stores..
GM restoration parts ONLY means a fee was paid to GM to use the GM name, it has nothing to do with originality, country of origin or quality.
redvetracr- actually there is more to it. I license products for diagnostic imaging developed by my company and the terms and conditions of the license agreement, which is typically 25-30 pages written by an attorney, contain quality specifications and remedies if the licensee does not meet the specifications. GM does the same. This is their product summary: "GM assists licensees in obtaining original specifications, blueprints, and tooling (when available) for applicable parts, as well as the use of the Chevrolet Restoration Parts Emblem. These features allow for the manufacture and/or sale of quality parts with the same value and fitment as the original parts. EMI is GM's exclusive agent trademark licensing representative for the management and administration of the Chevrolet Restoration Parts Licensing Program"
As I stated, the parts will be as close to the original as you can get and better than Autozone, NAPA, AdvanceAuto, etc.
As I stated, the parts will be as close to the original as you can get and better than Autozone, NAPA, AdvanceAuto, etc.
Hold onto that dream. There is zero QC.
The emblems for example are made in Taiwain, and you can visually tell the difference.
Not saying they are all trash, but you can tell the difference.
OP- I hope you kept your original MC that has the bleeders. While you have a replacement on the car, you can do a little project and rebuild your original (easy project). Get a rebuild kit from one of the forum vendors (I paid $30.00 for mine) and also buy a brake hone. When you're done rebuilding, you'll have the original in like new condition to put back on the car. Check out youtube for a how-to video.
Duane
Big bird- thanks for your comment, but what is the solution- not to order the part? I have spent over $35K in parts on my 68 convert and usually get items that are indicated in Eckler's, Zip, Paragon, etc as restoration parts and stay away from parts described "will not receive full NCRS judging points" or other disclaimers. I tried to go on the cheap getting a part from the local car parts store and got what I paid for- a cheaper quality part. The one I re-ordered is a restoration part that cost three times as much, and I expect will be better quality.
I bought my "new" genuine GM master cylinder thru Rock Auto. It came in a GM box that said "Made in China" on the side. I haven't had a problem with it though.
Big bird- thanks for your comment, but what is the solution- not to order the part? I have spent over $35K in parts on my 68 convert and usually get items that are indicated in Eckler's, Zip, Paragon, etc as restoration parts and stay away from parts described "will not receive full NCRS judging points" or other disclaimers. I tried to go on the cheap getting a part from the local car parts store and got what I paid for- a cheaper quality part. The one I re-ordered is a restoration part that cost three times as much, and I expect will be better quality.
No easy answer. Just trial and error,gleaning knowledge from old timers here, and gut intuition.
I start by seeking NOS GM, and paying double because it is cheaper in the long run, and go from there.
"paying double because it is cheaper in the long run" BB, you got off cheap. The Advance Auto part, which had "Wearever" and "made in China" on the box cost me $49.99 with a lifetime warrantee. (Not sure if that is the car's lifetime or my lifetime, which would be considerably shorter). I paid $160.99 plus $25.89 shipping for a correct casting number DC 5455509 master cylinder from Eckler's which they advertise as a GM restoration part. We'll see where the expensive part is made.
My super duper master cylinder finally arrived from Eckler's today. I was anxious to see where it was made that justified the triple times cost vs a Chinese part from Advance Auto with "Wearever" as the brand. The MC is made in the USA by Corvette Stainless Steel Brakes, Inc., 14364 SW 139 Court Miami, FL 33186, a family owned business started in the 1970s to make stainless steel calipers for Vettes. The MC is well made, fits well, and now I have brakes. It came with two youtube videos that described the QC done on the part- made in their own shop- and also how to bench bleed the MC. I wish I knew about these guys two years ago when I replaced rotors, calipers, hoses and brake lines. Now today also the MC.
02-26-2019, 11:37 PM
aftermarket brake master cylinder
