I've seen a few of these posts on this site, but I'd figure I'd start my own and document from start to finish my progress. My car is a '66 Buick Special Deluxe with 58,000 miles, manual brakes and a 300/310 wildcat. I purchased a dual master cylinder conversion from inline tube. I have heard different things about them, good and bad. Anyways, yesterday I removed the master cylinder and lines. After inspecting the difference between the push rods of the single well and the dual well I have determined that I will need to come up with a custom push rod because the single well is way different than the dual. Has anyone sucessfully accomplished this? Would I be better off getting one off a '67 with manual breaks? After searching the posts and what not I've seen people that have had issues with the length of a custom push rod and others who have broke a few of them, which is scary. I've seen kits out there, if anyone has any advice I would definately love to hear it. I'll post some pictures tonight. Thanks!
me too. is the diameter of the dual mc rod larger also besides length. i have been told to watch out for a larger diameter rod. they say it takes more force. thanks jim
I am looking at a few kits and I may go with this push rod kit on Jegs. The forum will not let me post links yet so here is the part number. A1726 - Stainless Steel Brakes Adjustable Master Cylinder Push Rod
Here are some pictues of the new parts and old MC. I have to buy a new front passenger line because of a frozen bolt.
If you look at pictures I posted they are two different animals. Unfortunately I didn't find out until I took everything apart. The old setup has a large plunger held in place by a clip. When you remove the clip the whole thing comes apart. I have a picture of the old push rod (above) and it has a large end to it that will not fit in the aftermarket MC hence a whole new setup. I don't think a dual MC exists that will directly fit the OEM single MC push rod setup.
Update: I got my kit from inline tube and the fitting for the rear line in the brass distrubution block is 7/16" not 3/8" as the original has. I am working on getting the proper fitting installed on the line.
I see in some threads that people used a proportioning valve for power drums, do I need to install one for manual drums? I'd figure the kit I bought from inlinetube.com would come with one if so.
Here's the link: http://www.jegs.com/i/Stainless-Steel-Brakes/884/A1726/10002/-1 Did you order this one?
Yes that is it! I haven't put it on yet because I have to hook up the rear line still and didn't want to install the MC until I do that. If I get the line hooked up tomorrow I will try out the pushrod kit and give my feedback on how long I had to make the rod and what linkage I used. The horseshoe shape linkage is the same as what was on the original hookup to my break pedal so I am going to try that first. I may have to bend it a little, but am not sure yet. Now that I think about it, I can try just to test fit it without the MC in place. I'll try that. Also, I have to see if the push rod fits in the MC hole, I'm almost certain it does but I haven't been able to visit this project completely until today.
only disk brakes use a proportioning valve. all drum brakes use a distribution block. when i replaced the brake lines in 2001 in my 72 gs, i purchased them from inlinetube. i have since purchased other items from them with no problems at all.
Ok, so the distribution block for a 66 Skylark Special Deluxe with manual drums has 3/8"-24 3/16" tube all around. The part that inline sent me has a 7/16"-24 for 3/16" tube for the rear line. The guy at inlinetube said that in '66 the rear fitting is a 7/16"-24, maybe my car is using parts left over from a '65? Either way I'm sending it back and they are replacing it. So if you are going to get one of these kits make sure you specify what the fittings should be for the rear line and two fronts.
Nick, the single-master cyl cars used a 3/16" rear line...thru 1966. In 1967 GM used a larger 1/4" rear line with the dual master cylinder. No problem keeping the 3/16" line, but as you found out, the fittings are different sizes. A good auto parts store will have brake line adapters to use the small rear line with the larger junction block. Just make sure the adapters are for the 'inverted flare' brake lines.
I trust that you are correct. I'm going to send the block back to them and they are going to send me their '64-'65 block that has the 3/16" 3/8" rear line fitting rather than putting more fittings into the line. There already is a junction fitting under the drivers seat which I think is not street legal. The issue is that I have 3/16" 3/8" stock rear line fitting on my car while the block they gave me had 3/16" 7/16" fittings, in which they said was correct for '66. I told him that isn't right. My car has 58k on it and I told the guy at inlinetube that as well. He said it was common for people to just pick up parts and use what they had at the factory. ??? LOL The rear lines aren't stock though. Maybe the person who replaced them used an earlier junction block at the shop? Who knows, but it looked 100% stock to me. I have pics above of it. Thanks everyone. I'll let you know how it goes.
Joe...Live and Learn, Grasshopper! I just went thru this on a disk swap on a 66, so I leaned a few things along the way. Nick...you are on the right track. You are getting a conversion dual master cyl junction block for 64-65? That outta do it. The 66 used normal size fittings on the 3/16" line.....the nuts would have 3/8" threads. 1967 used extra-large nuts for the 1/4" line....I believe the rear line NUT was 2 sizes bigger.... 9/16" threads! Don't worry about a splice in the line....as long as the lines were double flared, and the right fitting used, it'll be fine.
Update: I have installed the push rod kit and have blead the breaks with a pressure bleader. I have a rock hard pedal, shouldn't there be some play? Also the pedal sits a bit high, I'm having a hard time remembering where it sat before I started this project. I have a picture, if any other '66 owners can check it out let me know. The push rod kit I used above worked great with a few modifications. I had to widen the fork piece that attaches to the break pedal and also cut the supplied threaded doll about an inch. I just have to do a few minor adjustments to it still and I think I'm ready to test drive.
