I have my 41 year old rear drum cylinders still on my car. They were always used with a manual booster. I am in the process of hooking up my Hydroboost with a Wilwood master. That's going to significantly increase the pressure these cylinders will see (it better, anyway!). Do these things ever fail catastrophically? Or should I just replace them now while things are torn down?

No, they won't unless the shoes go out way too far and allow it.

I would replace them anyway if I were you but I found out the hard way that the repros made in China will not fit in between the fingers on the backing plate.

I finally found wheel cylinders made in the USA :hurray:

No, they won't unless the shoes go out way too far and allow it.

I would replace them anyway if I were you but I found out the hard way that the repros made in China will not fit in between the fingers on the backing plate.

I finally found wheel cylinders made in the USA :hurray:

OK.... and where do I find them too?

I know that Advance and O'reilly has (had) the China made ones that will not fit.
I finally found them at Carquest Auto Parts (at double the price.)

I know that Advance and O'reilly has (had) the China made ones that will not fit.
I finally found them at Carquest Auto Parts (at double the price.)

Why am I not surprised about the Chinese stuff not fitting?

Sure way to check if something is American made....Check the price. If it is 2x the other product you are likely on the right track to finding something that is A: American made and B: Gonna both fit and work.

Paraphrasing an old saying I first heard when I was a kid:

Good help (parts) aint cheap and cheap help (parts) aint good.

Yes, wheel cylinders can and do blow out. If your cylinders are in good shape you can hone them a little and put new innards in them. A propery rebuilt cylinder can work just fine. Look for deep pits or other damage to the inside. Rebuild kits are easy to do and will usually cost less.

I bought a pair of these (http://www.napaonline.com/Search/Detail.aspx?R=UBP37021_0253358522) wheel cylinders last time I did the rear brakes. Label on the box stated assembled in USA. :thumbsup:

I got the wheel cylinders that fit between the fingers on the rear of my 66 from NAPA.

Ground up has them also, but I finally got to a NAPA store one day and they were in stock.

Autozone and Advance tried, but the listing was wrong. They gave me a set to try, and the index part that goes in the opening in the backing plate was too big.

Interesting coincidence on NAPA. I was out and about, and stopped by. Yup, they had some, PN 37021 for a ridiculously cheap $8.31 each. The box says "Hecho en EUA", "Fabrique Etas-Unis", and my favorite, "Made in USA".

LS7, the link didn't direct me to a specific part, but I assume it's these I bought. The guy at the counter is a motor head that I remember working at the local part joint since the 60's.

Interesting coincidence on NAPA. PN 37021 for a ridiculous $8.31 each. The box says "Hecho en EUA", "Fabrique Etas-Unis", and my favorite, "Made in USA".
:yes: Yep, those are the ones. :thumbsup: