# 70 GTO manual drum brakes



## WDMelvin (Jun 23, 2014)

I have a 70 GTO with manual drum brakes that I am working on. These brakes are terrible at their job of stopping the car. The pedal is high and stiff but little in the way of stopping action short of standing on the pedal. I am not talking about fade or air in the system as the pedal is not spongy and does not drop to the floor. I was on a hill stopped at a stoplight and almost had to feather the clutch to keep from going backwards as the brakes barely even just held the car there. Does anybody have any ideas? I have not driven a manual brake car in a while but these are worse than anything I've ever driven before. I've got to dive into them and any help as to what to look for is greatly appreciated. Thanks.


----------



## Jared (Apr 19, 2013)

My LeMans has the same set up as you have. The pedal is extremely hard as well and you have to press pretty hard on it to stop and stay stopped, especially on hills. As this is the only car I've ever owned with manual drum brakes, I have assumed that it is normal. Mine do a good job stopping the car as long as enough pressure is applied. I will say, there is little room between enough pressure on the pedal and the brakes locking up. I plan on swapping the fronts to disk, but keeping them manual as I have grown to like the hard pedal feel.

Maybe others can give their opinion to help you out.


----------



## WDMelvin (Jun 23, 2014)

Thanks for the response. I'm not sure these brakes would even lock up. I had a 69 GTO and I could never get a hard pedal from them so I never experienced having to stand on them this hard. This car also only gets 100 miles on it in a good year so I'm wondering if things are getting bound up just from lack of use. We probably will switch to front power disk when $ is available but for now I'd like to get these working better. My 67 Le Mans is getting them during the resto for sure.


----------



## pjw1967 (Mar 10, 2014)

Waaaay over my pay grade here. But check the wheel cylinders and the self adjusters. If you google bad wheel cylinders you get all kinds of symptoms. I have power brakes on my '67. Twice I had problems. Once when the master went bad. Full of rust. Then one or more of the wheel cylinders went and I had no brakes. Always a good idea to flush the system too. Brake fluid absorbs water and deteriorates over time.


----------



## WDMelvin (Jun 23, 2014)

Those are the 2 symptoms I was told to look at and was where I was going to start. I was thinking possibly the master cylinder too. Seems logical to think it is just not pumping hydraulic power to the wheel cylinders. Should know right off if the adjust ers are bad. Ive never done drums before but I have a manual so they cant be that hard to do.


----------



## geeteeohguy (Feb 2, 2008)

I have drum brakes on both of mine, and the '65 is manual. Stops like a dream. Locks up the wheels at any speed. The only drawback is slowing the car down from very high speeds....well over 100mph. These brakes are self energizing, that is, the shoes pivot to compound the leverage against the drum. All springs must be in good shape, and the backing plates where the shoes ride must not be grooved. Also, check the contact of the shoes against the drums....they should be in 100% contact, as evidenced by an even gloss on the entire shoe. In the old days, shoes were arc-ground to match the drums, and this helps a lot with stopping ability. This is no longer done, but broken in shoes should be a perfect match. Jack up the car and have a helper apply the brakes while you try to turn the wheels. You should not be able to, at all. My bet is you have mis-adjusted brakes, tired hardware, bad shoes, or all of the above. If one or more wheels isn't locking up, check for pressure at the wheel cylinder at that wheel. Wheel cylinders can freeze up and not work at all, but remain leak free. Hope this helps. These systems are really not bad at all, but need to be in good condition to work as intended.


----------



## PontiacJim (Dec 29, 2012)

The type of shoes you use will have a big effect on braking. The shoes are usually offered in different grades & prices, a low grade, mid grade and premium. My '68 Lemans has drums and acts the same way, but I went with the higher dollar metallics. Poor stopping quality and I have all new brake parts as I rebuilt it all. Have had to use the aid of my transmission by dropping a gear in emergency situations on a couple "right now" stops in traffic.

What I have learned from testing brake grades on my old Toyota, and some other vehicles, is that you want to try the inexpensive/cheapest grade shoe your parts store offers as they are softer and actually grab better. They will wear quicker, but not anything rapidly or uncommon.

Did you ever question why brake shops guarantee for life the cars brake pads? They use the hard metallic which takes a lot of miles to wear out, BUT, they warp & wear out your rotors. So they make their money not on the pads, but the rotors and labor again and you feel good because the pads were under a lifetime warranty. The metallics work best under high heat, but they generate heat too. They stop great for front disc brake cars, but the next thing you know, you have warped rotors and you get that shimmy through your steering wheel. Once I went to the cheaper/softer pads, I no longer have warping rotor syndrome -and my little Toyota stops great with them.

So, my suggestion if you do your own work, get a set of the cheap/lower end non-metallic softer shoes, install them, and see if you find any difference.


----------



## rickm (Feb 8, 2012)

back in the day raybestos made two sets of brake shoes, blue box n red box. part #s 246 n 242 front n rear. the red box had a softer lining for manual brake cars, blue box was harder for power brake cars. if you install blue box shoes with the harder lining on a manual brake car, you will have a good pedal but the car wont stop too well. manual brake cars require the softer linings to function well.


----------



## WDMelvin (Jun 23, 2014)

All great stuff guys. I won;t be able to get to them until at least the weekend but I will weigh in on what I found. Thanks.


----------



## geeteeohguy (Feb 2, 2008)

rick and jim, nail hit on the head. The red box was also the high asbestos content organic (oh no!) and what I have on my cars. Anything metallic will stop better when very hot, but not for normal driving where you are cut off in traffic and need to whoa right now. Have experienced the 'hard pad soft rotor' scam for years..rotors dished out and needing replacement for $$$ while the pads are warranted or the opposite: one large chain even went so far as to machine brand new rotors to their minimum service thickness, guarantee their super _soft_ pads for life, and actually had special steel rivets on the pads (not brass) so when the pad [wore, the rotor was instantly trashed, necessitating replacement. Total scam. Cheap, asbestos based organic shoes, a clean and groove free backing plate, Wagner or Raybestos spring kits and wheel cylinders, proper adjustment and drum diameter, and it will stop no problem. Measure the drums, and take a good look at the adjusters, too.


----------



## WDMelvin (Jun 23, 2014)

Outstanding. Thanks again and I'll let you know how she turns out. Hopefully they are not so good he won't want to switch to disks! HA HA!


----------



## WDMelvin (Jun 23, 2014)

What wear specifically on the backing plate are you talking about or will it be obvious where the pads hit it? Also, do you put any kind of anti seize on the adjusting screw, or anywhere else for that matter, or will that just help retain brake dust and guarantee seizure? Thanks.


----------



## WDMelvin (Jun 23, 2014)

Are pads supposed to be shiny after some use?


----------



## PontiacJim (Dec 29, 2012)

WDMelvin said:


> What wear specifically on the backing plate are you talking about or will it be obvious where the pads hit it? Also, do you put any kind of anti seize on the adjusting screw, or anywhere else for that matter, or will that just help retain brake dust and guarantee seizure? Thanks.


No anti-seize. Keep everything dry, but make sure they are clean and screw in easily, no binding.


----------



## PontiacJim (Dec 29, 2012)

WDMelvin said:


> Are pads supposed to be shiny after some use?


You do mean shoes, right? Pads are for disc brakes. Shoes are for drum brakes.
Yes, they get shiny. Should be smooth with no gouges, cracks, uneven wear, or raise ridges. Same goes for the drums, no grooves, no cracks, and uneven wear.

Sometimes if a shoe has been over heated, it can become "glazed" -which also looks shiny. While drums are off, you can give the shoes a light sanding to scuff them a bit, but don't go crazy in an effort to sand them down or off -just a light scuffing. At least this is what I do, but others might have some comments on this.


----------



## Jared (Apr 19, 2013)

I scuff new pads as well. Just a trick I picked up from my dad. I figure it can't hurt to get anything that may have gotten on there from your hands during the install off. Maybe overkill, but it can't hurt.

One other thing you may want to look at is how old the lines look. I have seen lines collapse with age which can cause two different problems. One is what you are seeing, the other is brakes that won't release after several stops. Both bad.


----------



## WDMelvin (Jun 23, 2014)

I did mean shoes. Sorry, have not worked on drums in a while, actually never. I'm convinced the fronts were worn out and thr wheel cylinders were not working right in all 4. Dad wants it to go to a brake shop. I'll be sure to get soft shoes. Thanks for the help to all.


----------



## WDMelvin (Jun 23, 2014)

1 more stupid question as the manual is not terribly clear of I'm looking in the wrong spot, front drums, do you have to remove that inboard seal to get the inboard wheel bearing out? Obviously if it has to come out it has to be replaced? Thanks.


----------



## WDMelvin (Jun 23, 2014)

Im going to give these a shot myself not a shop. Thanks.


----------



## Jared (Apr 19, 2013)

The seal has to come out to remove the inner bearing. Sometimes you can reuse the seal if you are very careful removing it. Either way, the seals are only a few dollars. Make sure you're careful not to scratch the race. A brass drift is almost a must when working around bearings. Also, make sure you clean, dry and inspect the bearings before you put everything back together; now is the time to replace anything that looks questionable. Also, make sure you properly pack the bearings.

Since this is your first brake job, do you have anyone who can look over your shoulder while you do this? Also, there are a couple specialty tools for removing and installing brake springs that will make your life a lot easier. Just take your time and only do one side at a time and you should be fine. Good luck with it!


----------



## WDMelvin (Jun 23, 2014)

I've got everything to do the job. Drums are in great shape with little if any wear on them, no ridge and popped right off. Adjusters were not frozen and all the springs look fine as well. It'll get shoes, I'll scuff them a smidge, cross sand the drums per the manual so they burnish, R&R the wheel cylinders, change the inboard seals. With regard to the inner bearings, I know how to pack them but there is some room between the bearing and he lip of the seal, does that are get filled up with grease or no? Thanks.


----------



## geeteeohguy (Feb 2, 2008)

Not really. You can add a little grease there if it makes you feel better. Just make sure there is adequate grease on the bearings, and if the backing plates are grooved where the shoes ride, hit them with an abrasive disc to smooth them out.


----------



## WDMelvin (Jun 23, 2014)

All 4 backing plates looked good. I got organic bonded shoes which the guy told me were the softest he carried. SHoul dhave it done tonight and will let you know how it turned out. Thanks.


----------



## geeteeohguy (Feb 2, 2008)

Don't expect full braking until the shoes are broken in and fully seated. Probably about 1000 miles of driving.


----------



## WDMelvin (Jun 23, 2014)

Ok thanks for that. I'm not completely covinced the automatic adjusters are working right. Hopefully I can get them bled and tested out tonight.


----------



## Instg8ter (Sep 28, 2010)

you will know the first time you back out after doing them, if you get good pedal after a few pumps in reverse they are working.


----------



## WDMelvin (Jun 23, 2014)

I got it done and I could not ghet them bled right. The pedal was squishy and I spent a couple hours trying to bleed it all out to no avail. I did the old back and forth with it and it may have improved a bit but not much and did not notice the pedal coming up much. Not sure how much the air in the system is effecting it. Overall, it was pretty easy other than the bleeding and will keep driving it for a bit to see how they improve but I think in the end they will improve a lot especially after a good bleeding. Thanks again for all of your feedback.


----------

