The Stovebolt Site Forums The Shop Area Driveline Parking brake adjustment question?

Adjusted my parking brake yesterday on my 1949 Chevrolet 1/2 ton pickup according to the shop manual. Released all the pressure from the NEW cables, set pedal at 1 1/2 inches from fully released. Pulled cables as far as I cold pull them and then adjusted the clevis to align with the clevis holes on the cross bar. Brakes have all been adjusted so I have a slight drag at each wheel. I still don't seem to have parking brakes when engaging the pedal. Both back wheels still turn with just a little more drag than with the pedal released. Shouldn't back wheels almost lock up with the parking brake engaged? Any ideas or suggestions?


Tim

I think some of the replacement cables are too long. On mine ( 50 GM ) with all new brake components the cables are at the end of the adjustment and just locking the wheels. I modified the cable stay to take the extra slack.

Just to comment on your question, the parking brake should hold the truck on a good steep hill.

Is your emergency brake one where you push the pedal down with your foot
????
If so, make sure when it is pushed down that it stays down. If the pedal does not stay "fully" depressed than the pedal release rod might have to be bent slightly to grap the pedal tighter...

Cables seem to be adjusted properly. How far out do they need to be pulled? I pulled them out as far as they would go by hand and then lined up the clevis. The pedal is staying completely engaged and releases good.

Tim

Hand lever operates a rod to a bell crank which pulls a cable which runs thru a pulley to a pivot bar which pulls on two "L" brackets with threaded cable ends held to the "L" bar with nuts to adjust length of cable. Be sure it's all original stock hardware first. Then adjust threaded ends to shorten cables. The other area is inside the drum, that could be installed wrong, broken, etc. E-Brake cable pulls on rear shoe only. Has there been anything done recently? Was this working before?
Above is 55.2-59 info, your 49 is probably similar.

If shoes are adjusted and inner E cable is tight, there is enough "throw" in the pull lever to actuate a stock rear shoe/mechanism.
I guess it seems like I'm talking down to you now that I see your background. Not meant to. I hope the NEW cables are correct. Doesn't sound like they are!!!!
As Tnix said, they should not "almost" lock up, they should lock up tight.

bartamos,

Thank you for the reply. Talking down to someone only makes you look small. None of us should talk down to any member on this forum. We all want to learn on the Stovebolt forum and receive good answers from members who have had similar experiences. If you persist in bantering in an unprofessional manner, insulting other members will only alienate yourself from these members who want to learn.

First, my parking brake is not operated by hand. It is a foot pedal operated system. It has NO bell crank or pulleys. Foot pedal operates a cross bar under the back of the drivers side fender with two rods going to the back of the truck and a large return spring that attaches to the rear cross bar. The rear cables attach to the rear cross bar with clevis and pins. Second, The cables are new and attached properly at the frame and rear brake shoes. Third, I asked how far the cables needed to be pulled by hand with the pedal pushed 1 1/2" from the full released position. I would like this questioned answered as the manual does not designate just how far to pull the cables. I understand that if the cables are too tight this will cause the brake shoes to pull away from the drum resulting in nor e-brake. All brake components are new including the wheel cylinders, master cylinder, e-brake cables and lines.

I hope this information I've given will get me some suggestions that may correct my concerns with the parking brake. Mainly, how far to pull the cables before adjusting the clevis and attaching them with the pin to the rear cross bar. Any suggestions?

Tim

I don't know about your truck but on my 38 Master I pulled the cables out as far as I could and used a pair of channel locks to hold the cable while I adjusted the rod. I am pretty sure that using all the strength I could muster, I probably could not produce much drag. Have you any idea if there is any tension in the system with the pedal down?

really
I had to replace my back shoes to get mine to brake, probably not your problem though..

I had to make the hole smaller where the pedal shaft goes through the floor. Its the flat steel piece that holds both a spring and two washers. The hole was all worn to one side. I made a plate with the proper size hole and welded it to the face of the existing plate. Also the brake shoes needed replacing all this helped. Online old chevy car manuals there is a section on our type of Ebrake adjustment. There are so many clevises and rods that this Ebrake system had to be designed by an aircraft engineer. My old 49 had a floor hand brake it was simple. I always carry a tire block if parking on a slope. I don't trust the Ebrake it's a suck system!
Steve

Hey Fixy,
I will agree that the Truck Shop Manual leaves much to be desired in terms of adjusting the brakes, including the parking brake.
The '49 Huck brakes have an eccentric bolt which holds the toggle lever in place.

From page "Brakes 5-19" under "REAR-(1948-50) 1/2 TON..."
2. Assemble toggle lever to new shoe, making sure that the high side of the eccentric attaching bolt is toward the brake shoe facing.

There is no reference as to what that eccentric bolt does or if there is a need to change it after the initial setting is made.
If I were you, I would pull the rear drums and check the eccentric bolt position. Also check the position of the flat bar which goes between the two shoes above the axle. (The Manual calls it "the strut".) These are forked on the ends and need to engage properly for the parking brake to work.I would then have someone set and release the parking brake several times while you watch whats going on. Make sure nothing is getting bound up giving you a false "tightness" at the cable adjuster.
Carl

Thanks Carl,

That is what I was looking for!! I will check the eccentric bolt on both sides. Put the drums back on and have a helper push the pedal to make sure I am getting proper tightness with the e-brake.

Tim

Old Online Chevy Manuals does not have 1949 truck. Just a 48-51 truck and a 1949 car manual. The car is hand op. In the 1949 car manual is also says when new rear shoes are installed it is necessary to adjust the toggle lever with the parking brake link by means of the eccentric bolt. May or may not be of interest. A picture is included in the 1949 car manual.

The only answer I see regarding your question on how far to "pull cables out of the conduit" is: "As far as possible" (truck) and "until positive stop is felt" (car). That's it, that's the answer from the manuals. Then tighten nuts.
During E-Brake adjustment, one wheel may lock better than the other. Manual says adjust that other wheel at that point. Maybe if all else fails, that you can eliminate the 1 1/2" preload (or some of it) while adjusting and see if that helps. I know it's there so that the return spring(s) can operate using a little slack.

Talking down was the wrong word. Just tried to say I didn't realize you were a GM Factory Trained Technician. Automotive restoration and design, teaching, drag racing person.

bartamos,

Pulling the cables "as far as possible?" That's a statement with a lot of questions....by hand?, with locking pliers?, with a screw driver in the clevis and your foot on the back tire for leverage? You definitely got my question! Yes, the shop manual leaves a lot to be desired and questioned. I guess I will just pull the cable until it won't pull any more. Check the eccentric bolts inside the rear drums and watch for any binding with a helper as Karl stated.

Thank you for the info and clarification.

Tim

Sometimes those guys who wrote that stuff had never done it. You are the latest Guinea pig. You are almost there. I never use an emergency brake. That way I never forget it's on. I use first gear. It was meant to use as an emergency, redundant brake that needed no hydraulic pressure. Then someone started calling it a parking brake and then all hell broke loose! It's why Godzilla got mad over in Japan.

I usually use the 48-55 foot-actuated parking brake whenever I park.

If you use it, get into the habit of releasing it everying time you start the truck.

"Adjusted my parking brake yesterday on my 1949 Chevrolet 1/2 ton pickup according to the shop manual. Released all the pressure from the NEW cables, set pedal at 1 1/2 inches from fully released. Pulled cables as far as I cold pull them and then adjusted the clevis to align with the clevis holes on the cross bar. Brakes have all been adjusted so I have a slight drag at each wheel. I still don't seem to have parking brakes when engaging the pedal. Both back wheels still turn with just a little more drag than with the pedal released. Shouldn't back wheels almost lock up with the parking brake engaged? Any ideas or suggestions?"Tim

I know this way late, but I did have the same problem and fixed it for me. When the parking brake would not engage after pulling all the slack out of the brake cable by hand, I installed a pliers-grip to keep the cables extended with the parking brake pedal all engages. Then remove the parking brake cable cotter pin and clevis pin. Next, release the braking pedal and adjust the clevis to line up with the extended cable. Next remove the pliers-grip.

This worked for me on my 1949 Chevy 3100 truck.

To follow up on this OLD thread, I just checked the service manual and the parking brake adjustment is actually a 2-part procedure. The first part on page 5-11 is the initial adjustment of the cross shaft and cables. That part is the one that talks about depressing the pedal 1-1/2 inches. THEN on page 5-14 is the parking brake adjustment that says put the parking brake pedal in FULLY RELEASED position, detach the cable clevises, pull them out by hand and adjust so the clevis holes line up with the cross-shaft levers and replace the clevis pin and cotter pin.
This is similar to what bosco24 did.

Why they didn't put all that info on the same page is a mystery.

To add to what Kevin said, the cross shaft is one piece with both levers that the clevis pins attach to move exactly the same. So if the cables that go to each brake assembly are not adjusted the same, the tighter cable will contact first, applying that brake and the other side will still be loose. Under this condition, you will have only one side that actually engages the brake.

My brakes are adjusted properly and when the emergency brake is depressed it holds the truck on a slope. But the brake does not hold and it releases by itself. Not a safe situation. What is the fix for this?

Make sure the rod that contacts the release is clean and free from any grease.

Look at that little tab that the brake handle stem slides through. It's probably worn out sometimes I'm able to get mine to hold if it hangs up by twisting the handle clockwise or counterclockwise slightly

You might be able to get it to hold by pushing down on the locking bar (push the release lever down), but that's unlikely to fix it permanently.
I think the proper fix is to dismantle the pedal assembly and repair the locking bar by sharpening up the edges that the round rod passes through. If they're worn too much, they won't grab the rod dependably. You might have to put a weld bead on the edges and redrill the hole.