removal of wheel cylinder nut.

[TwoFiftyShifter]

Huh, my GMC wheel cylinders mount differently..... the two bolts instead of the nut..... My truck is nutless.

[fuzzinator]

I had the exact same problem couldn't get that bolt out. What my problem was the backing plate was bent and putting the bolt in a bind. I destroyed the bolt and finally broke the wheel cylinder and used a punch to break what was left around the bolt. Got the wheel cylinder out of the way and spun it out by hand.

If you tear up that bolt let me know I have a spare.

[DWright]

time for the 'ole heat-n-beat method.....

[Chuck78]

What a lot of you guys seem confused about is that on mine, I had the same problem - the rear drum wheel cylinders bolt in from the rear with two bolts (and 4wd fronts?), but 2WD fronts on my 62 GMC have a really large bolt with the spring pivots attached (as pictured, looks like a giant bleeder screw). I used my torque wrench as a breaker bar, since it was the longest ratchet I had. WIth a lot of force and a lot of pushing inward on the socket as to not let it come flying off, I got it off. Then the flat washer behind it gets bent back over as a lock washer, sort of like the locking tabs under exhaust manifold bolts.That flat lock washer is a thick bugger, took a lot of hammering and chiseling to get off!

I just tried to rebuild my front wheel cylinders as one was leaking, and i am swapping to discs eventually ($35/cyl is pricey!, $3 kits are cheap!), but I broke off a bleeder screw in one. Still need to do my rears, anticipating the same fate, as my line fittings into the wheel cylinders are pretty darn rusty.

[Chuck78]

I doubt a torch is necessary on these, as the way they go on there, when I pulled mine out, the threads looked clean as a whistle, shiney as they were when they came off the assembly line! They really seal up in there well into the spindle. Just need a good quality socket that has the hex starting not too far in (it's a shallow head), and use a lot of pressure to keep that socket from torquing off sideways and screwing everything up.

How did the other side go?

[madaca]

The front drivers side went well after I got a better wrench. Was pretty tight but I got it off with a little muscle. The passenger side is just seized on there. i am putting all my might into it....every muscle I got and it will not budge. Im thinking maybe the other came off a little easier since it sat over night with some wd40. Hopefully when I try again in a little while the wd40 will have done the same. Ill keep ya all posted.

[Corts60]

By far the best penetrant I have ever used is PB Blaster. I haven't come accross a bolt yet that won't come out with that stuff. I suggest you pick up a can of that stuff, let it soak for an hour, and give her hell!

Also, if you can, make sure your using a 6-point socket as that will give it a little extra bite and it won't want to strip the bolt as much.

I think I used a deep well 6-point on a 1/2 drive ratchet.

[kizer]

Yep PB Blaster is king when it comes to loosening bolts.

Soak it, heat it, soak it and it will come loose. Even a stubborn bolt you soak it, loosen it, soak it some more and it will come loose without breaking.

Of course there are some bolts that you have to soak and let sit over night, but they normally will come loose.

[madaca]

Well I finished the brakes guys. I ended up buying some of that Blaster spray and let it soak and the I had to use a pipe wrench with a breaker bar and it finally came loose. It was extremely tight and I wore myself out taking it off. I could only move it a little at a time but I got it. There was some rust on the bolt. That is probably why it was so tight. The rear was a lot easier since they had two small bolts holding the cylinder in. It took long to bleed the brakes but me and my friend got it done.

My next question is are the brakes on these old trucks pretty soft. I mean after bleeding the brakes especially the master cylinder, the brakes go down about half way. The brakes are engaging. I didn't get to test drive it since I got done so late but when I spin the rear wheels they do stop. I could also see the brakes moving on the rear when I had the drum off. So should that brake pedal go down pretty far before brakes engage?? You guys have been a lot of help. Thanks.

[Corts60]

They shouldn't have to go down that far. Did you adjust the brake shoes using the adjuster bolt? It is on the bottom of the shoes and you adjust it with a flat screwdriver from the backing plate through a little slot..

When you do this, have the front end jacked up and spin the wheel and adjust little by little until you start to hear the shoes drag the drum. That should be about right. Check your brakes again after that and see how they feel....

[madaca]

so the brake pedal going down halfway is too far? I did adjust the brakes like mentioned. I adjusted them until I couldnt spin the wheel anymore then back out just a little. Maybe I still have some air in the lines. The fluid seemed to run pretty solid though. When I first press the pedal it is soft but then hardens up after it is pumped a couple of time. That that mean anything. Sorry for so many questions. I just want to be sure I do this right.

Edit...I just check it again and actually it is still soft. It does not go all the way to the floor. It goes about half way, maybe a bit more but it is kind of soft. I feel tension but not how newer cars feel. Should it be hard when I press it?

[Chuck78]

My pedal goes down about halfway, and then is really firm, with 4 wheel drums. Anytime you depress the pedal and it feels soft, and then you pump it a few times and it comes up higher, that ALWAYS means you still have more bleeding to do.
I usually use a basic rule of thumb that when I press the brake pedal, I should be able to slide my other foot under the pedal still, and that is a decent pedal height.
Soft pedal with stock setup means air in lines. Soft pedal with mismatched/upgraded parts combinations could mean that your master needs to be larger bore or your pushrod is on the pedal arm in the wrong place, but yours is not the case with these two.

Try the gravity bleeding method that I;ve been reading other guys swear by on here... open bleeders, let it drain on it's own into a can. Keep checking master and topping it off. Don't press the pedal at all.

[madaca]

Oh and also, in my owners manual it says the brakes are self adjusting? Says to drive forward and then backward and stop using firm pressure on the pedal. Says after a few times pedal travel should return to normal. How does that work?

[madaca]

Thanks Chuck. I think I will try the gravity bleeding method when I get up. I really think air is still in the lines. I will try again and update everyone once I finish tomorrow.

[TwoFiftyShifter]

Dont's forget the star adjusters..... Turn them in and it should help...

[Chuck78]

I think on most drum brakes newer than my 62, they have a little lever that engages on the star nut only when braking while the vehicle is moving backwards, and it adjusts to the proper tension that way. You can also manually adjust the star nut from the oval slot in the backing plate once you have the drum on. That is, if you put it in the right direction when reassembling the brakes. The star nut is going to be closer to one shoe than the other, and you will notice the slot on the backing plate is as well. The star nut threads into the other piece that is closer to the center of the axle, and just pivots on the piece that is further away from the center. That will help you when knowing which way to turn it.

There is a special tool that makes it a lot easier to adjust than just by using a screwdriver, and basically looks like a double sided flathead screwdriver that has the flat blade ends bent up/down at an angle.
When putting the drums on, you should try and crank the star nut out as far as you can while still being able to slide the drums on, and then fine tune them just a little but once the wheels are on so you can spin them and crank it in some more until you hear a little drag. This adjustment will help your pedal height and ensure that your rear drum actuating e-brake works!

[DWright]

my '66 has slots on the drums themselves. i just mounted the rallies so that the holes in the wheels line up with the hole in the drum. i dont even have to remove the wheels or get under the truck to adjust brakes

[madaca]

I bled the brakes again by gravity bleeding and got all the air out. Fluid ran solid all the way around. Much easier to do by gravity bleeding. Never done it that way before. I drove the truck down the street to fill her up and it died. I messed with the carb and got it to start and continued to the gas station. Added some fuel treatment a d carb cleaner and ran it around d the block a few times and it started running much better. I still need to rebuild the carbs later. I guess I still need to adjust the brakes because I had to push all the way to the floor to get it to stop. I will adjust them tomorrow and see if it helps. Do you guys adjust the brakes until the drum stops or until you hear them rub? Also I think I need to clean my plugs. The truck seemed to lose power going uphill. What else could be the cause of that? I'll post more tomorrow.

[madaca]

I bled the brakes one more time and there was a little air still in the lines. I adjusted the brakes as well and they feel much better. I have never drove a truck with drum brakes before. How should it feel. It goes about half way and then feels hard but the brakes do not seem to stop the truck fast. I have to really press firmly to get it to stop good. Is this because they are not power brakes? I am glad I got some progress but just want to be sure I have them where they should be. thanks again.

[Corts60]

A firm foot is definitely required to stop manual drums and they will never feel anything like power discs....

When your bleeding the brakes and someone is holding the pedal to the floor, are you tightening the bleed screw before they let off the brake pedal? If not you could be pulling air back into the system......

[Chuck78]

yeah, with manual brakes, you really have to stand on them to get them to stop real hard. They really will stop you as good as an average sized disc brake setup (the first time). If you're on long hills with lots of braking, or drive like a maniac light to light with hard stops, you will notice some definite brake fade with drums up front.
I don't mind the manual brakes at all really, but the manual steering really stinks on parallel parking and parking lot maneuvers. I've been told by my veteran mechanic father that if I had manual brakes still with front discs, I'd wish I had power, as the discs require a lot more fluid.

[madaca]

Ok that is good to know. They do come to a stop when pressed and they do feel firm but if I had to come to a quick stop I would really have to apple some pressure to make it happen.

Now I gotta figure out why my emergency brake isnt engaging. I looked under the truck and tried adjusting the cable. The cables are nice and tight when I pull the e-brake but it is not engaging the brakes. any suggestions on the e-brake. Thanks again everyone. So much great help and info here.

[Chuck78]

Ya know, my ebrake doesn't stop nearly as well as the hydraulics in the rear... I haven't really done much to the rears yet other than adjust them. Got new wheel cylinders, but the line fittings are a bit rusted and I'll probably have to redo all the axle lines when the time comes just to bleed the system when I swap to a dual master cylinder and dedicated rear brake line.
As far as the 4 wheel drums and having to really stomp on it, granted with more pedal effort needed, but I can get my 4100 lb GMC panel truck with 4 wheel drums to lock up all 4 wheels MUCH easier than I can with my 5200 lb front disc brake 1989 Suburban with power brakes.

[madaca]

Hey guys can someone help me out again with these drum brakes. I am still not happy with how they feel. I have a feeling I just need to adjust them some more. When i adjust the brakes, do I adjust them until I cant turn the drum anymore or until I just here some drag. I am having to press the pedal all the way down and sometimes it does not come to a stop. I really need to get this fixed this weekend. I checked for air again and the fluid is running solid and I have no leaks. The fluid is staying at the same level when I fill it up. I just want to make sure I am adjusting the brakes properly. I know some people are saying a little drag but how much is a little? Someone else told me to adjust until they stop and I can't turn them easily with my hand any more. Any help is appreciated.

[Alan's Classic]

Did you take any pics along the way. I'd like to see the brakes assymbled with out the drum on. Front and rear if possible.

I adjust to a drag. Then drive and readjust and check.

Have you done anything to the MC like replaced it? How did it stop before all of this work?

Are the flex lines original/old?