47-55.1 Brake pedal return spring

[72Mountaineer]

Originally Posted by NeoJuice

That is a great picture 72Mountaineer. I did the exact same thing this weekend. I made a little L bracket and hooked the other end onto a hole in the transmission housing that was right across from the brake pedal. It was a PITA to stretch that spring to get it hooked into place.

See attached video I made of the new spring pedal return spring in action.

https://photos.app.goo.gl/SqMBAJAfVVBipBsj9

What are you going to use for a pedal switch?

[NeoJuice]

I used a willwood prop valve with built in break switch.

https://www.wilwood.com/MasterCylind...emno=260-11179

I can post some pictures tomorrow if your interested.

[dsraven]

Nice job no. Some units must have more built in friction to overcome than others.
Curious what you have for a pedal stopper.

[NeoJuice]

Originally Posted by dsraven

Nice job no. Some units must have more built in friction to overcome than others.
Curious what you have for a pedal stopper.

Nice job no? LOL Must be a typo. I'm not using any kind of pedal stopper just the stroke of the booster/master cylinder and dont have any issues. Of course this is with the proper adjustment of the pedal height/stroke.

[dsraven]

Sorry, yes. Typo.

[jwhotrod]

the only thing that i will add is if you use a pressure switch for your brake lights do yourself a favor and use that switch to control a relay for your brake lights. we have in the streetrod crowd have long experience with pressure switches. if you want it to live a long life do not subject it to the amperage the brake lights use. It will fail at the most inopertune time if your not careful.

[NeoJuice]

Originally Posted by jwhotrod

the only thing that i will add is if you use a pressure switch for your brake lights do yourself a favor and use that switch to control a relay for your brake lights. we have in the streetrod crowd have long experience with pressure switches. if you want it to live a long life do not subject it to the amperage the brake lights use. It will fail at the most inopertune time if your not careful.

That's probably a good idea. Can you recommend on how to wire it? If I remember correctly from my painless wiring harness I just wired the orange 917 and white 918 wires directly to the pressure switch for the brake lights.

[jwhotrod]

the orange wire is your brake feed from the fuse block, it is orange because it is a fused battery feed that is hot all the time. that wire should go to term 30 also put a jumper from term 30 to term85 which is the control circuit on your relay. the white wire is the cold side of the brakes that goes up into the column that wire goes to term 87 which is the NO terminal. ok last thing is run a black wire from term 86 whichis the other side of the control circuit to one of the terminals of your pressure switch. the other terminal of the pressure switch should also have a black wire that attaches to a good ground. so what the press0ure sw0itch is doing is switching ground on the control circ0uit and will not see any amperage. I hope this helps.

[72Mountaineer]

Now having some more brake problems, they seem to be hanging up. I installed a Wilwood residual 10lb. valve in the rear, and a 2 lb on remains in the front. I drive the truck about 10 miles, could tell that the brakes were hanging up somewhere, as I could smell the brakes. MC/Booster is under the floor, S10 front discs, GM Camaro 10 bolt drums in back. I have read a few posts about setting up booster to MC adjustment and booster/pedal adjustment. How do you do this? Maybe this is my problem.

[dsraven]

Google how to set the master to booster pushrod and also the linkage to booster pushrod.
Check master cyl for a res valve as some rebuilt units may have them in their outlets already

[dsraven]

Brake fluid expands when it gets hot.
Seems like the problem is possibly no play in the master cyl pushrod or linkage to booster set up. That means fluid goes out but cant get back to res when your foot comes off the pedal. This keeps brakes lightly applied, they heat up, the fluid expands, they get tighter, the problem compounde itself.
Jack it up right after a test run to warm things up, check if the wheels turn easy or not, if not then Try loosening the nuts a few turns that hold the master cyl to the booster and right away recheck the same wheel that was hanging up. If it turns freely then your master cyl is not able to return fully so some checking is in order.
If that doesnt seem to be the problem then tighten it all back up, do a few hard brake applications and then loosen the bleeder screw on the wheel that is hanging up. If there is more than the pressure expected from the residual valve then you may have a faulty res valve. Tighten it all again, hit the brakes again a few times and release, this time crack a brake line before the res valve or at the master. There should be basically no pressure before the res valve. If you have access to see into the res you could have a buddy step on the brakes while you look into the res with the lid off and safety glases on. When the pedal is first stepped on there should be a couple of small fountains in the res until the madter cyl piston travels past the fill holes in the bore, then fluid will pass into the oulets and eventually build pressure in the system. Then, when the pedal is released 2 more little fountains should appear in the res fluid when that fluid returns to the res and system pressure goes to zero, before those residual valves.

[72Mountaineer]

I've been looking for a linkage to booster setup and cannot find something. You mean the linkage from the pedal belcrank to the booster? Essentially the play in the pedal? Found good info for booster to MC adjustment on Youtube. I didn't get a chance today to tear into it, next 2 days are rain from hurricane, then thurs. dr. appt. 3 hrs. away, might be fri. before I get into it.

[dsraven]

There has to be play between the belcrank pushrod, that pushes into the booster, and there also has to be play between the booster pushrod at the booster to master cyl end and the master cylinder piston. That is 2 different measurements at 2 different spots. Google the booster to master cylinder clearance for a better description but if worst case scenario, get the dimension that the booster rod sticks out past the master cylinder mount, then make sure that dimension is shorter than the depth of the end of the master cyl piston where the 2 come together.

[72Mountaineer]

Makes a big difference! Thanks dsraven!

[dsraven]

No problem, glad it worked. Nice job, by the way.

[dsraven]

Just looking closer at the pic. Does the bolt with the nylock nut protrude out past the nut a little? The nylock can only "lock" if there are threads for it to grip. Im sure its probably fine but you dont want that bolt to fall out due to a nut coming loose.

[dsraven]

Also, and you are possibly not done the job yet, I noticed the heim joint has no jam nut on the threaded rod. Is that something that is yet tobe done? It should have one) or a set screw on the heim joint but that scenario will make it hard to take apart or adjust later. They do make thin jam nuts for stuff like that.

[youngrodder]

Great thread!!

Funny, I just completed this modification on Suburban that uses the same frame mount brake pedal. last week No more doing the river dance while driving by always kicking the pedal back up.

It's funny how the most minor of fixes can make the drive so much more enjoyable. I pout about 150 miles on this weekend and it was great.

Marc

[72Mountaineer]

Yeah, everything is coming apart again. I received the gauge to adjust the pin in the booster today in the mail, it took a week to get here and was only 6 hours away. Never thought about the jam nut, good call. I still wonder about the booster/pedal adjustment, guess I'll just experiment. I picked up a pressure bleeder from a friend, after the '53 I'll cycle my Silverado fluid. This has been a good thread, lots of good info. Thanks again dsraven.

[dsraven]

Be carefull bleeding antilock brakes, they dont bleed the abs pump unless you have a scan tool. If you happen to get air in the system you also need a scan tool to open the valves in the abs pump

[dsraven]

I assumed your silverado has ABS. If you do one wheel at a time and ensure the master doesnt get close to running low so air gets in, you should be fine. I dont personally pressure bleed ABS but instead do the old fashioned "step on the pedal" bleeding using a one man bleeder container. No problems except the ABS pump doesnt get bled that way. I figure it doesnt hold much fluid anyway. The other thing to do, I suppose, would be to bleed the bakes, ten go for a spin and make the antilock actually operate, then blee5bleed the brakes again. That would get fresh fluid in the ABS pump. Long way around a problem though.

[dsraven]

Sorry, should have checked my spelling and gramar before hitting post, lol.

[dsraven]

The booster to lever free play doesnt need to be much, but it does need play. That's one reason why I was harping on having a definite pedal stopper. The pedal needs to stop in the same place when released so that free play doesnt have a chance to change from when first built and set up
I see you have a rubber stopper built in, that should do the trick. The only thing I might suggest is to add an adjustable hard stopper as a fail safe. Like a bolt and jam nut next to the rubber, so when the rubber conforms to stress the pedal still has a definite end point but the pedal would normally rest on the rubber.

[dsraven]

On second look at your pic I see the rubber stopper is actually your stop light switch? Oops. Well, a pedal stopper could look a lot like that, just a bolt and nut instead of a switch. Use a bolt with a plastic or rubber tip added to help absorb vibrations/squeaks. Or integrate the original pedal stopper that goes on the brake pedal lever and bottoms against the firewall. I can still remember that "thump" noise when my dad was starting on a hill and would dump the brake pedal quickly so he could hit the gas pedal right away. Haha.