uh6077 Posted November 5, 2015 Share Posted November 5, 2015 Let me start by saying I am not a total idiot, I promise. I have a 68 Imperial and since I bought it a few months ago the brakes have always been iffy. At low speeds they were very strong but at a high speed stop I could tell they were not grabbing like they should. Took everything apart and found the front shoes to be really glazed. I had the drums turned and put in new shoes. The system was not opened at all. I set the adjuster wheels to give a slight drag. Well that was 2 weeks ago and I still have not been able to get the brakes working again. The pedal is very soft and goes a few inches before any resistance then it feels like air in the system (again it wasn't opened up so shouldn't have air in it). Played with the adjusting wheels again but that didn't help. With the drums off I can see the shoes moving fine. So I bled the system numerous times with no change. Tried it with wife helping (typical push, hold, release, repeat). Tried with my two bleeders (mity hand held vac and a air powered bleeder) and still no change. Started bleeding at rear passenger, rear driver, front passenger then front driver. What the heck am I missing? Right now the brakes are not even strong enough to stop the car quickly at idle so it is no where near safe to take on a test drive. HELP!!! Link to comment Share on other sites More sharing options...
Bhigdog Posted November 5, 2015 Share Posted November 5, 2015 If you got the shoes from NAPA or a big box store in all probability they have totally wrong friction material for your car. What you are going through is EXACTLY what I went through for two years and three sets of shoes for my 57 Buick. Go to the Buick forum and search for relevant threads. See if you can bring up poster named Oldtank. Lots of info there....................Bob Link to comment Share on other sites More sharing options...
Alfre Posted November 5, 2015 Share Posted November 5, 2015 If your peddle is soft the master cylinder is in need of rebuildingAl 1 Link to comment Share on other sites More sharing options...
uh6077 Posted November 6, 2015 Author Share Posted November 6, 2015 Yes the pedal is soft but it wasn't at all before I changed the shoes and turned the drums. Link to comment Share on other sites More sharing options...
Spinneyhill Posted November 6, 2015 Share Posted November 6, 2015 Did you radius the shoes to fit the drums? Otherwise the soft pedal is just you bending the shoes in an attempt to get them onto the drum. Link to comment Share on other sites More sharing options...
uh6077 Posted November 6, 2015 Author Share Posted November 6, 2015 Hmmm, I didn't even think of that that would make sense. I will take them apart tomorrow and have a look. Assuming the drum is are not making contact with the whole shoe how can I them them? Just heat them with a torch and open/close the bend as needed? Link to comment Share on other sites More sharing options...
plymouthcranbrook Posted November 6, 2015 Share Posted November 6, 2015 Have you bled the master cylinder? Link to comment Share on other sites More sharing options...
Beltfed Posted November 6, 2015 Share Posted November 6, 2015 Take your drums and shoes to a shop that can radius the shoes to fit the drums. I dropped off a front set today to get them done. Be sure to mark which shoes fit which drum. Link to comment Share on other sites More sharing options...
misterc9 Posted November 6, 2015 Share Posted November 6, 2015 (edited) Don't torch anything. A 68 Imperial should have front disc brakes and a dual master cylinder. What ever is going on sounds like a hydraulic problem . Air some where in the system or maybe a master cylinder with only one side working. The disc brakes they used were four piston type and known for problems. Are the new shoes identical to the old ones especially where the wheel cylinder pushes them. Does this car have the "silver bullets" where the wheel cylinder pushes on the shoe? Are they properly engaged? Edited November 6, 2015 by misterc9 (see edit history) Link to comment Share on other sites More sharing options...
uh6077 Posted November 6, 2015 Author Share Posted November 6, 2015 It is a 66. I have too many dang cars and projects and they just blend together sometimes. If they are disk brakes then I have a really big problem because the drums slide right onto the spindle :-) Link to comment Share on other sites More sharing options...
JACK M Posted November 6, 2015 Share Posted November 6, 2015 There was some discussion recently about using sticky back sand paper on the inside of the drum and sanding the shoes to fit.Sounds easy. Link to comment Share on other sites More sharing options...
uh6077 Posted November 6, 2015 Author Share Posted November 6, 2015 Took everything apart today to see if anything was obvious. Shoes and drum look to be perfectly mated. Not that having a specialist arc them would not help but I don't think that is the problem right now. I pushed the wheel cylinders all the way in to make sure there no pocket of air trapped. Bled everything again. Set the self adjusters to give a slight drag. Everything back together and still no change. Worked the emergency pedal in and out a dozen or so times to see if the adjusters would set themselves, still no change. Back and forth int he driveway a few dozen times (neighbors probably think I am bonkers) but still hardly any brakes. At this point it has to be the master right? Maybe putting on the new brakes and put a strain on it or something. I will try to find one locally but probably have to order it. If that doesn't fix it then I am at a loss as to what else it could be. Did I mention it has power brakes? Could the booster be bad? Link to comment Share on other sites More sharing options...
Beltfed Posted November 6, 2015 Share Posted November 6, 2015 The old test for the booster is to put your foot on the brake pedal with a little down force, engine off. Start engine and the pedal will drop by a 'felt' amount. Maybe like a 1/2", 3/4" or so. Link to comment Share on other sites More sharing options...
keiser31 Posted November 6, 2015 Share Posted November 6, 2015 I would say master cylinder needs a rebuild. Link to comment Share on other sites More sharing options...
vermontboy Posted November 7, 2015 Share Posted November 7, 2015 NAPA will have master cylinder and booster - they were used for a number of years but it might be a good time to convert it to a dual master cylinder., An Imperial has enough weight to go a long way without brakes (I know from personal experience with a 1964 - the emergency brake only worked with the pawl in Park .(pushbutton transmission). Link to comment Share on other sites More sharing options...
uh6077 Posted November 7, 2015 Author Share Posted November 7, 2015 It already has a dual master, must have been converted at some point. I found a refurb unit at Pep Boys. I bench bled it and will change it out tomorrow. Link to comment Share on other sites More sharing options...
uh6077 Posted November 7, 2015 Author Share Posted November 7, 2015 Replaced the master, bled the brakes again and it is better. Went for a test drive and she stops again. Still not great but I should be able to adjust it a bit. At around 50 mph it slows down quickly but then the last 5mph or so it seems like it isn't grabbing like it should. Also the emergency brake isn't working so looks like the rears may be out of whack a little. Link to comment Share on other sites More sharing options...
Graham Man Posted November 10, 2015 Share Posted November 10, 2015 (edited) You should be able to lock up the tires. I would check the brake shoe material. I stopped buying shoes because they do not specify what brake material they come with. I send my old shoes in and have them relined by a reputable brake shop (about the same price just slower, but worth the wait). I also like to have the master cylinder relined with a stainless steel works better for cars that sit a lot. This is who I use... Brake and Equipment Warehouse455 Harrison Street NEMinneapolis, MN 55413Phone: 612-378-3141http://brakeandequipment.com/index.php/machine-shop.html Edited November 10, 2015 by Graham Man (see edit history) 1 Link to comment Share on other sites More sharing options...
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