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I purchased a rebuilt master cylinder (MC) for my 1964 F600. I bench bled the MC until there was no slack. Then I reinstalled the MC on the firewall but every time I re-connect the brake line to the MC, it looses fluid and I can never get the pedal to firm up. Am I missing a step here? How do you bench bleed the MC then reconnect the brake line without losing fluid? Also, I don't understand how the flare on the brake line that connects to the MC does anything... Unless I just can't see it, I don't see anything for the flare on the brake line to pull up tight against inside the MC. HELP
On the front of the M/Cyl there is a fitting screwed into the actual cast iron master cylinder. There is, what I believe to be a crush washer that goes in between this fitting and the m/cyl reservoir itself. These fittings I would highly suspect would NOT be included with a rebuilt master cylinder assembly. The fitting would have the female portion to receive the flare fitting and seal it up properly. When you unscrew the brake line from the m/cyl as you have it now closely inspect the flared area to be sure that if there is no fitting on the new m/cyl and you have been trying to put it together unknowingly incorrect that the flare is not damaged or distorted. Also look to be sure there isnt any cracks or issues like that.
If this is the case...and Im assuming you have hydraulic brakes which based on your post it sounds like, both of these two items are readily available
The fitting is p/n 7EQ2077A and the gasket as the parts book calls it is p/n 91T2154A, Green Sales is the only place with both items on their shelves.
Their number is 800-543-4959
- cs65
Last edited by camperspecial65; Jun 29, 2010 at 04:19 AM.
Reason: added info
On the front of the M/Cyl there is a fitting screwed into the actual cast iron master cylinder. There is, what I believe to be a crush washer that goes in between this fitting and the m/cyl reservoir itself. These fittings I would highly suspect would NOT be included with a rebuilt master cylinder assembly. The fitting would have the female portion to receive the flare fitting and seal it up properly. When you unscrew the brake line from the m/cyl as you have it now closely inspect the flared area to be sure that if there is no fitting on the new m/cyl and you have been trying to put it together unknowingly incorrect that the flare is not damaged or distorted. Also look to be sure there isnt any cracks or issues like that.
If this is the case...and Im assuming you have hydraulic brakes which based on your post it sounds like, both of these two items are readily available
The fitting is p/n 7EQ2077A and the gasket as the parts book calls it is p/n 91T2154A, Green Sales is the only place with both items on their shelves.
Their number is 800-543-4959
- cs65
I looked at the old master cylinder that I took off and didn't see the fitting you mentioned. (maybe that's why it was leaking in the first place). Do you happen to know anyone that has a parts diagram of the master cylinder? It would really help me out if I could visualize the problem. My master cylinder has only one outlet that points toward the front of the truck. It also has a hex nut style fill cap. It has four bolts that mount to the firewall.
I don't mind ordering the parts, I just want to make sure I'm ordering the right ones.
Hello, I to have an F-600 and went completely through the entire brake system. And found many problems along the way. As camperspecial65 said there is an adapter fitting and copper crush washer on the master cylinder, it would be my guess that you may of gave it up with your core. Anyway make darn sure you get the right M/C or your brake rod may not be the correct length. This would cause both hard or soft peddle or make bleeding impossible. The rod should have some play between the cup and the rod. Also other things that you should really check and replace is the three rubber lines ( a must ) they deteriorate over time and cause fluid not to pass through them. I built a power bleeder from a one gallon pump sprayer and a spare master cylinder cap. I hope this helps.
I wanted to let you know that you were correct. I ordered the nipple that connects to the master cyliner and its nice an dry. Thank's so much for you help. I still don't understand why the old MC wasn't leaking since it didn't have the nipple and the MC is identical. But I'm OK with accepting succes and moving on.
Originally Posted by camperspecial65
On the front of the M/Cyl there is a fitting screwed into the actual cast iron master cylinder. There is, what I believe to be a crush washer that goes in between this fitting and the m/cyl reservoir itself. These fittings I would highly suspect would NOT be included with a rebuilt master cylinder assembly. The fitting would have the female portion to receive the flare fitting and seal it up properly. When you unscrew the brake line from the m/cyl as you have it now closely inspect the flared area to be sure that if there is no fitting on the new m/cyl and you have been trying to put it together unknowingly incorrect that the flare is not damaged or distorted. Also look to be sure there isnt any cracks or issues like that.
If this is the case...and Im assuming you have hydraulic brakes which based on your post it sounds like, both of these two items are readily available
The fitting is p/n 7EQ2077A and the gasket as the parts book calls it is p/n 91T2154A, Green Sales is the only place with both items on their shelves.
Their number is 800-543-4959