Are these 9" or 10" brakes?

[MrPolecat]

Howdy folks. I can't get to this thing to pull the wheels off and look at it today, but I am trying to figure out if I need the wheel cylinders for 9" or for 10" brakes. Hoping to be able to get some parts ordered this morning and get them in time to work on it this weekend...

It's a 1966 CJ5 with the F-134 motor. It has the single-reservoir master cylinder with the offset threaded plug in the top like you'd see on 9" brakes (I think). But looking at where the lines connect to the wheel cylinders, I am thinking maybe it looks like 10" drums, considering how the rear one looks angled instead of 90 degrees...... I was thinking 9" brakes when I measured them last time I was down at the shack where I have this thing parked, but now I am not so sure.....

Sorry about the poor pictures. What do y'all think?

Front.


Rear.


Thanks, y'all. I really appreciate your help, and I apologize fer my ignorance!

 

[Posi]

All of the 1966 CJ5s with a V6 and "most" of the F-heads in that year had 10" brakes. If your 5 is an early 66 chances are their 9". To be positive I'd recommend pulling out the measuring tape again.

 

[MrPolecat]

Thanks! Will do.

My serial number seems to indicate that it was built in Dec 1964 and then sold as a 1966, so I am all over the place trying to figure out what is what. Heh.

Turns out that the Friendly Local Independent Auto Parts Store ordered both the 9" and 10" wheel cylinders anyway, just in case, so I think I'll just pick up all 8 of them and head down on Saturday and then return whatever I don't use.

 

[Posi]

I just noticed your sig suggests your not sure if you have a front 25 or 27. You can find a casting number (25 or 27) on the webbing on the diff, right side, closest to the tube. You have to look from the top down, or use a mirror from under the diff.

 

[duffer]

That year Jeep should have a D27 front axle and it does likely have the 9" brakes. If you are completely rebuilding the brakes, it will be cheaper to just find the 11" backing plates and switch to 11x2's. Parts more readily available and cheaper, not to mention they work much, much better. Do a search on 11" brake conversions on Early CJ5 and there is also a section on the 3B Page for this conversion.

 

[MrPolecat]

Thanks! They are indeed 9". Already started the rebuild; just have the rear wheel cylinders to replace yet and the bleeding and it'll be done. Then on to the rest of what is wrong with the thing!

I don't know what the deal with the old wheel cylinders is, though. The 9" new Warner ones I bought (listed as correct for this model) fit fine, but the old ones are way, way different.