1961 bad new master cylinder?

[Bob63]

I’ve just completed installing all new brake lines, front and back, along with a new master cylinder. The M C was bench bled before installing. The lines were then bled with farthest wheel around to the closest wheel using speed bleeders on the back and original bleeders on the fronts. I’ve pulled all the drums to check condition of shoes, wheel cylinder cylinders and adjusters. Everything looks good - no leaks, good (1/4” plus) thickness of the shoes. Drums are very good with no scores. It looks like the car had a full brake job in not too distant past.
The p o installed a new booster according to receipts I got with car.
After finishing all this the brake pedal goes to the floor and I’m wondering if the new master cylinder is bad. There are no leaks in the system and the m c is maintaining fluid level.
Are these new master cylinders prone to being bad out of the box ? Before I buy and install another is there a quality, trusted brand that will actually work?
Sorry to be do long winded but this is getting frustrating.

 

[Ward 57]

I’ve just completed installing all new brake lines, front and back, along with a new master cylinder. The M C was bench bled before installing. The lines were then bled with farthest wheel around to the closest wheel using speed bleeders on the back and original bleeders on the fronts. I’ve pulled all the drums to check condition of shoes, wheel cylinder cylinders and adjusters. Everything looks good - no leaks, good (1/4” plus) thickness of the shoes. Drums are very good with no scores. It looks like the car had a full brake job in not too distant past.
The p o installed a new booster according to receipts I got with car.
After finishing all this the brake pedal goes to the floor and I’m wondering if the new master cylinder is bad. There are no leaks in the system and the m c is maintaining fluid level.
Are these new master cylinders prone to being bad out of the box ? Before I buy and install another is there a quality, trusted brand that will actually work?
Sorry to be do long winded but this is getting frustrating.

I think your diagnosis is correct. I would check with NAPA. I really trust their products and they have great inventory for older cars.

 

[74 Harley]

Look into a Wilwood master cylinder. Especially if you get one with an aluminum body. They last much longer.

 

[oldcarguy34]

I’ve just completed installing all new brake lines, front and back, along with a new master cylinder. The M C was bench bled before installing. The lines were then bled with farthest wheel around to the closest wheel using speed bleeders on the back and original bleeders on the fronts. I’ve pulled all the drums to check condition of shoes, wheel cylinder cylinders and adjusters. Everything looks good - no leaks, good (1/4” plus) thickness of the shoes. Drums are very good with no scores. It looks like the car had a full brake job in not too distant past.
The p o installed a new booster according to receipts I got with car.
After finishing all this the brake pedal goes to the floor and I’m wondering if the new master cylinder is bad. There are no leaks in the system and the m c is maintaining fluid level.
Are these new master cylinders prone to being bad out of the box ? Before I buy and install another is there a quality, trusted brand that will actually work?
Sorry to be do long winded but this is getting frustrating.

You made no mention of adjusting the brakes. Did you do it?

 

[Bob63]

You made no mention of adjusting the brakes. Did you do it?

Yes, brakes were adjusted so that the drums made light contact with the shoes. I also cleaned and lubricated the adjusters. Cables seem to work the adjusters properly.