The 1960 - 1966 Chevrolet & GMC Pickups Factory Correct Restoration Thread

[f66]

Need help with parts numbers and ID. Attached are pictures of my 1966 C20 Bendix power booster and master cylinder. My understanding is these trucks could come with either Bendix or Delco Moraine boosters and M/C.
Questions:
1. The M/C has part number 618082 cast in the bottom and has a screw on cap. Is this potentially an original or replacement original?
2. What are the Bendix part numbers for the Master cylinder, and part number for the booster?
3. What are the Delco Moraine part numbers for the Master cylinder, and part number for the booster?

Thanks for the help, Frank

[yelmer]

the parts book calls for moraine unit #5465489 1.0" bore with booster . booster 3834112 bendix (2501747}

[f66]

Yelmer, thanks is my master cylinder the right part number? Also where is the part number on the booster? And last, are the boosters date coded?

[yelmer]

i have never seen a date code on a booster . the master cylinder looks right some had screw on tops and some had clip on tops

[f66]

Yelmer, Thanks. I am going to pull the booster this week. Will check for a date code, and post pictures if I find anything. Thanks again Frank

[yelmer]

looks to be a date code on the master cylinder ?

[f66]

Originally Posted by yelmer

looks to be a date code on the master cylinder ?

Yes, there is a 66 cast in, and some faint”clocks” which probably indicate month/day. Need to find a source or someone who knows about the Bendix manufacturing process to confirm..

[f66]

Originally Posted by f66

Yelmer, Thanks. I am going to pull the booster this week. Will check for a date code, and post pictures if I find anything. Thanks again Frank

I pulled the Booster today. I am providing pics of the front and back. I have only found 2870 stamped into the booster adjacent to one of the M/C mounting studs. Should there be additional stampings? One thing I did notice was each shell has an "X" Scribed in at the the 12 o'clock or top. Leads me to believe that the booster was rebuilt sometime earlier. That is consistent with the history I know. The longtime previous 2nd owner was a mechanic and probably serviced the part himself vs just replacing. Also included pics of the booster mounted on the Kent Moore Tools the dealers would have used to service the booster in their service dept. These are shown in the shop manual.

[60-66]

Originally Posted by f66

1. The M/C has part number 618082 cast in the bottom and has a screw on cap. Is this potentially an original or replacement original?

I have that exact same 618082 master cylinder on several low mile trucks. 8700 mile 65 K20 , 18,000 mile 66 GMC , my gold 66 K20 22,000 mile truck. Thats two Janesville and one Flint built trucks. I've found these same master cylinders NOS on 64-66 Bendix boosters. I believe that master of yours IS correct and original for your truck . Ive sent mine out to Lone Star Calipers to have stainless steal sleeves installed and restored.