Picked up a Chevy 12 bolt with 11 inch drums and I need a good part number so I can replace the leaking 15/16 inch wheel cylinders (can't find any part #s on the current cylinders). I read somewhere that using the ones off a 77 Cutlass work perfectly without any mods... is this right? o No:
Look up cylinders for wagons....I believe the 70-2 Cutlass Vista Cruiser used larger rear drums and wheel cylinders....NAPA should have them.
The 70-72 Vista Cruiser (68-69 Sportwagon as well) did use bigger rear brakes, but they were 9.5x2.5 which are the same as the fronts. The wheel cylinders are specific to those models and EXPENSIVE when found. Also, they are RH/LH as the brake lines were angled. The 11" drums you have on the 12 bolt are likely from an Impala. Am guessing from 68-72. Check with Rockauto and look up the wheel cylinders for that or even a 77-84 Electra or Estate Wagon as they had 11" rear drums in most cases. This should give you some ideas. Good Luck
I had a very difficult time finding those sportwagon wheel cylinders but did and now i have a complete NOS set of sportwagon rear brakes for my 67 special including the correct backing plates
Thankx for the help guys! After much research I wound up going with the ones for 76-77 A-bodies because they have the correct 15/16" inch bore size, they're for a car of comparable weight, and they fit either side. Auto Zone Part #33469 (WC37048, WC13469, WC51081, and 28-51081 also cross reference to 33469). Thankx again!
Still have to look into this as I am working on a 69 Sportwagon rear. The larger backing plates may not fit on the non-Sportwagon rear. If you look at the SPW rear, the lower shock mounts are narrower than the non-SPW rear. There is a chance that the wider SPW drums will interfere with the shock mounts. They may clear, but I have not mounted the larger backing plates on a non-SPW rear yet. Another possiblity is to use the 9.5 x 2.5 front drums in place of the SPW drums as they do not extend past the backing plate (chevelle front drums may work too). Just a little heads up on this as I was told there was an interference problem with swapping backing plates. Again, haven't done it myself yet so am not sure. o No: Regards
Not an issue for me since it's a Chevy 12 bolt. Everything went together smoothly without any clearance issues.
