brake issue on 68 Electra (sorry I'm a Buick noob)

I just bought a nice Electra this weekend but it seems to have a major brake issue. The brakes do not seem to have nearly enough bite to them. I am unable to even remotely come close to locking up the brakes. I bled them last night and it didnt help anything. I have had a master cylinders and wheel cylinders go bad before and this doesnt feel like it at all. The pedal feels normal and returns normal. The system holds pressure fine it just seems that theres not enough "oomph" to it. I checked out master cylinders online last night and there appears to be a few different combinations and with me being the third owner I have no idea if the one I have on their now is correct. The engine bay pics I have found online appear to have a black booster but mine is a gold color. I was reading another thread on here and it mentioned something about two different sized rods that push on the piston in the master cylinder. If the previous owner installed a short rod on a long rod master cylinder would this cause my current issue?

I'm sorry about the giant wall of text and thanks in advance to everyone that hopefully responds.

 

It sounds like the system will stop the car, just not lock the wheels?? If thats the case I expect the master and wheel cylinders may be functioning normally. Make sure the vacuum check valve is working going into the booster and you have no major vacuum leaks.

Find a gravel road and see if all 4 wheels lock up. They should lock pretty easy. If they do, the next thing I'd do is pull each drum and check the shoes. If the linings are glazed from some past problems such as fluids leaks or over heating, you'll need to replace them. Wouldn't hurt to have the drums resurfaced as well. Keep in mind you may be dealing with original drums and really old shoes. Its worth it to resurface the drums and replace the shoes unless of course they look good. Thats a big heavy car to stop so investing in the braking system is money well spent.

If none of the wheels lock on gravel then would I look at the booster/master cylinder first making sure you don't have a vacuum supply issue.

 

I agree w/ jzriv...your shoes are probably glazed, and your drums probably need to be turned. I was the one talking about the rod...it was a different kind of problem than yours. A black, gold or silver booster really means nothing. It Is possible your MC is wrong (not the rod), there were different sizes of pistons internally. But forget that for now...you have to take the drums off and see what's in there!

 

Check to see that adjusters are all moving freely and operating properly also.

Devon

 

the throttle got stuck wide open yesterday (that's another story) and I had to stop it in some gravel of the side of the road...the brakes would not lock with me pressing the pedal down as hard as I can (linebacker in high school lol) and it barely stops. When puttering around at parking lot speed it will stop the car but anything over that and its pretty dangerous. there are no leaks and since the car doesn't pull to one side and appears to have an equal amount of low braking force I am thinking its something more centralized. I ordered a master cylinder and will see if that's the issue later tonight. While I have never had glazed drums on a car My pathfinder ( discs all around) does occasionally get a little glazy and I have found that a couple hard stops from 90 mph gets the bite back. The Buick doesn't seem to generate enough brake force at all.

another thing i noticed is that the front wheel cylinders use a different size bleeder screw 5/16ths than the rear 3/8s is that correct? im thinking of getting some speed bleeders would any of you be able know of any special part numbers for them?

 

some pics

 

x3 on the glazed shoes and drums. At least the next thing I'd check.

There are drum brake haters out there, but when in good working order as designed, (and not wetp ) they will stop these heavy cars in short order! Buick had a reputation of having some of the best brakes in the industry.

Nice looking Electra by the way! :TU:

 

thanks for the compliment. Local shop wants 500 bucks for a new vinyl top and it needs new seat cover but is pretty clean otherwise oh best part? ZERO rust! The undercarriage looks better than my 95 pathfinder. I really like this car but am having issues with it. The brakes being the most pressing thing at the moment. It also runs rough under load I think vacuum leak.

I'm pretty sure it isn't glazed drums/shoes or needing adjustment since I doubt all four wheels would be showing the same problem at the same time. It doesn't pull to any side which would show one wheel getting more braking power than another. I'm betting the previous owner put the incorrect master cylinder on it.

 

Snucks, congrats on the purchase! Looks clean! Can't put a price on a clean vehicle.

The different master cylinders listed for your '68 relate to whether they are front & rear drum OR front disc with rear drums. I would not jump and assume the master cylinder is wrong. Speed bleeders won't affect brake performance.

Please pull the drums on all four wheels and inspect the brakes. Your eyes will help solve the brake issue.

 

Booster or MC are likely culprits too. All those parts are fairly cheap, so a brake overhaul may be in order.

 

If the car sat for long periods than everything could be rusty and sticking even if it doesn't look rusty. It may be a hydraulic system but it's hydraulics moving metal pieces which pull springs and move levers and such. Couldn't tell you the last time I took apart a drum brake that didn't have a spring snapped off at the hook.

Don't assume that since it doesn't pull to one side that it's not an issue at the wheels. If the car sat than that means all the wheels sat and that means all the wheels could have the same problem.

 

Don't go throwing parts at it that may not be needed. Pull the wheels and drums and find out what condition the brake shoes and drums are in - check the wheel cylinders, and brake components while your in there.
If the car sat for a while it could be the results of a buildup of rust, and brake dust in the drums which has glazed the shoes, and reduced the stopping ability of those huge 'truck size' drums !! :laugh:
In any case, a brake job should solve the situation, but do a visual inspection, or have a qualified mechanic do an inspection before you start throwing money away on parts that you may not need! :TU:
Nice 225 btw !!

 

That's what I was talking about before with the rod length...those masters each take a different length rod.

 

I changed out my front drums/spindles on my '67 a few years ago for 2-piston front discs. Still have all the parts boxed up. If you need any parts, feel free to PM me. Sounds like you're having issues with shoes and/or the wheel cylinders. I did rebuild the fronts on mine a few years after buying the vehicle.

The discs I have on the front have been working well, though the drivers side started squeaking and I needed to dab some orange silicone on the pads. I was a bit put off to see that a lot of the components on my new system came from PRC.

Hope the commies don't come marching down the street for my car.

 

so the brake fluid was very dark and there was rust inside the master cylinder so I replaced it anyway since it was so cheap. This did not solve the issue. I popped the wheel off but was unable to remove the drum despite many smackings from a rubber mallet. I was also unable to turn the adjuster wheel either direction with a screwdriver or a small pick I had laying around. The drum spins freely there is no resistance at all. I will have to get a puller to take the drums off after work.

 

Note that the front drums come off with the hub, the rears just slide off the shoes.

- Bill

 

would you be able to list the parts for your disc set up?

---------- Post added at 02:46 PM ---------- Previous post was at 02:41 PM ----------

omg................................................................... totally explains why I couldn't get the dang thing off. I haven't worked on front drums since 1996. I remember having it apart and replacing the wheel bearings on my Cutlass when I had just graduated High school. good thing I ordered the service manual last night huh?

 

Drum brakes are fun!
I took apart the rears on my truck last week to replace the cylinders.
They're a little more complicated that a disc setup, but the hardest part was holding everything together while you try to put the retaining back on.
Mine hadn't been off in a few years so I had to spray down the hub and studs with penetrating oil, and hit it with a mallet on and off for a few days before it finally popped off.

 

I'm leaning heavily towards disc set up for ease of finding replacemnt parts alone. I cwnnot seem to source good drums at all. Does anyone kn now where I could find new reqr drums?