5450649 Wheel Cylinder for a 63 right rear

[Harry S.]

I tried to replace all my bleeders front and rear. Three were fine but one of the rear wheel cylinders would not accept the bleeder. The bleeder in the wheel cylinder was small in diameter. I went to my box of cores and they were fine.

I rebuilt one of my cores and installed it this afternoon. Time to bleed the brakes.

Anyone know why that wheel cylinder would have two different bleeder sizes?

Thanks

[Edward J.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Harry, I have seen this with aftermarket wheel cylinders very common,If it was NOS one it may have been a later service replacement ?

[Harry S.]

Re: 5450649 Wheel Cylinder for a 63 right rear

ED, it was NOS.

[Tim T.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Several years ago I purchased a set of supposedly original wheel cylinders and MC off Dec - Jan 1963. Correct part numbers.
When I went to rebuild them, I noticed the bleeders were small in diameter. Further investigation revealed they were metric threads!
All other threads were SAE. Was told by a retired Delco Moraine engineer, that worked in the brake division at that time, that this was not possible.
But I have proof. Please check yours, are they metric thread?

[Harry S.]

Re: 5450649 Wheel Cylinder for a 63 right rear

I'll take a measurement later today.

Some pictures to view.

The bleeder on the left is what was installed.

[Tim T.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Harry,

Looks identical to all 4 of mine. Are all the threads SAE except the bleeder and it is metric ? Have been told it is not possible, but the metric

bleeder screw is a smaller dia. than the "correct" SAE bleeder for that wheel cylinder !

Tim

[Alan D.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Harry, the original one on my Mar64 has a minor difference as picture shows.
Perhaps that may help tie down what's going on (do have same small bleeder)

[Edward J.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Harry it appears that there is a date in the first picture upper right corner, looks like (89)???

[Harry S.]

Re: 5450649 Wheel Cylinder for a 63 right rear

The bleeder is 8mm or M8x1.0, or
The bleeder is 5/16 or 5/16x24

8mm = .314961 incles
5/16 = .3125 inches
5/16 = 7.9375 mm


With the above I can't draw a conclusion as it's too close to call. It could be metric or standard?

Thoughts?

[Pat H.]

Re: 5450649 Wheel Cylinder for a 63 right rear

Harry, I have 4 of the 649's and they all have SAE 5/16 threads. 2 of them have been sleeved. Maybe someone cross thread one of them.