38 Plymouth rear bleeders

[38plymouth]

The bleeders on the rear wheel cylinders looks like a standard bolt with a very small second bolt screwed into it. The fronts are the standard bleeders. I need to bleed my brakes after replacing the front wheel cylinders and my wife is out of town. I would like to replace the rears with the regular style so I can put a hose on them and bleed the system alone. Anyone know if they fit? I don't have time this morning to pull one and check it. I saved the old ones from the front just in case.

[dpollo]

Just unscrew the entire bleeder and put in the newer type.  The little bolt is just a plug to keep dirt out.

 

The bleeder still  has a tapered end.

[TodFitch]

As noted by dpollo, you can simply unscrew the original style bleeder and screw in a new one. The only trick to that is that there are a bunch of bleed screws available nowadays, so you need to match up the thread, length and taper. Even so, a good auto supply store should have them in stock.

 

FWIW, that small bolt in the middle is listed as a dust cover or dust screw and is a 1/4 inch fine thread. Since I want to retain those on my car, I bought a 1/4 find thread cap screw (bolt), drilled a hole down the length of it and pressed in a small tube. It is a pretty easy operation to remove the dust screw, screw in my adaptor, push on a hose and bleed the cylinder. Probably only adds 30 seconds to the operation and since bleeding the brakes is a pretty rare operation it really is not a bother. The only bother is finding the adaptor after not using it for years.

 

The biggest thing for making the bleeding a one person operation for me is having made a pressure bleeder from a garden sprayer.

[Robert Horne]

My original bleeders have a 20 count thread per inch.

 

[38plymouth]

I was able to confirm that the new style bleeders from the front wheel cylinders do physically screw into the rears however I can't find a auto parts store locally that sells that size. These are quite a bit larger than everything they have in stock.

[TodFitch]

My original bleeders have a 20 count thread per inch.

 

Hmmm. Maybe they changed them over the years my car uses the 77671 bleeder screw but it looks like they changed on the cars in '39 to 691471, to 854039 for 40 and 41. P15s changed again to 1123005.

 

Here is the whole setup, and my "dust screw" is definitely a fine thread. For comparison, the hex cap screw above my adaptor is 1/4-28 and the one below is 1/4-20.

 

[TodFitch]

For a '38 Plymouth which uses the 77671 bleed screw with SAE 7/16 fine threads, my notes say that part 1263929 is the replacement. And 1263929 crosses to a modern NAPA replacement part is UP 11410.

 

See: http://www.ply33.com/Parts/group5#5-T

And: https://www.napaonline.com/napa/en/p/UBP11410/UBP11410_0205232810?interchange=1

[38plymouth]

Once again napa saves the day. Can't wait till they open a store on merritt island. Advance and AutoZone are virtually worthless.