Howdy! I'm just getting my new '67 Special hardtop in roadworthy condition, part of which involves my regular mechanic checking out the entire brake system and doing what needs to be done to get it working right. The front drum cylinders were leaking a little, and he ordered replacements, but they turned out to be "too big." Thinking he just got the wrong part, he sent them back and reordered, but the replacements were too big again. OPGI shows two different sizes, smaller in 1966 than 1967. Is it possible my '67 has the smaller '66 fittings? The mechanic is not a Buick or older car specialist per se, but he does have a 50's Buick regular customer and a number of other older cars going through the shop. Stumped in Georgia... Larry
Does it have power brakes? Or did it used to have power brakes? The smaller cylinders are used on power brake applications.
That explains it. Yes, it has power brakes (as noted in the title). Odd OPGI doesn't know to offer two sizes, isn't it? I will order the smaller cylinders. Many thanks, it's great to have support from those who know. :bglasses:
That explains it. Yes, it has power brakes (as noted in the title). Odd OPGI doesn't know to offer two sizes, isn't it? I will order the smaller cylinders. Okay, after going to rockauto to order, I'm confused again. The only 15/16 cylinders I can find on rockauto are for the rear drums.
The front wheel cylinders will be bigger bores than the rears, since they had a single reservoir master cylinder with no proportioning valve. It is possible that the previous repair got the wrong parts, and they got installed, anyway. I was at a shop many years ago where one of the customers had a problem with the front brakes pulling. The tech was having a tough time adjusting the brakes. I pointed out that the car had one 2-1/2" drum and one 1-7/8" drum. Somebody had put a rear drum on the front! You just never know what is going to have been done on a car this old. So, according to O'Reilly's fronts are 1-1/8" and the rears are 15/16". I'd recommend you find another "mechanic". He should have realized what was happening before this! These are the kinds of guys I call "parts changers"- just direct substitution of parts without, or with minimal diagnosis- that end up putting more parts on your ride than are actually required for the repair. Good luck with your repair.
Okay, so one response says there is just the standard size for the front drum cylinder, and another says there are two sizes, the standard size for manual brakes and a smaller one for power brakes (what size?). Anyone else want the weigh in on this one? I am wondering if I somehow got '66 drums up front instead of '67's, and if so how to tell. If I read my spec's right, '66 and earlier had a smaller wheel cylinder than '67 and after. I wouldn't give the mechanic such a hard time. Like I said, he's not an old car or a Buick specialist, just willing to give it a go and learn along the way. ....like me. I've got a fair amount of experience with old British sportscars and a little with Corvairs, but nothing with old Buicks. Just learning as I go.
The very first purchase you make after purchasing an older car is to get the Chassis manual. You can get them on E Bay, in re print, and even on CD ROM. It really is a must have. http://www.ebay.com/itm/1967-Buick-...anuals_Literature&hash=item51c67b66f3&vxp=mtr http://www.taperformance.com/proddetail.asp?prod=TA_3067 http://www.gearheadcafe.com/servlet/the-509/1967-Buick-shop-manual,repair/Detail
You are right. I was looking for the Assembly Manual first, as it has proven much more useful than the Chassis Manual for the Corvair, but since I haven't been able to find the AM for 1967 yet, I'll get a CM, which I'll also need anyway, as for this Q. .... Chassis Manual ordered. .... Still in a quandary on wheel cylinders tho.
