Pads come in a huge variety of friction compounds. Which ones did you get?
Disc brake question
Purchased my 62 lmpala less than a year and it already came with disc brakes front and rear , I noticed that I have to apply firm pressure in order for car to stop, I replaced all the brake pads and bled the brakes but still the same . My pedal does not go all the way down . Goes about half way my only problem is the brakes don’t grab and I have to apply the brakes kind of hard , I don’t know what brand kit this is, any input?
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Possibly air in the system, easiest test is to pump the brakes several times before applying them, if the car stops better it's likely air in the system.
It could also be as simple as one caliper not operating as well as the rest, and that could be a problem with the caliper itself or an issue with the brake line to the caliper. If the lines are still the old rubber type replace them with braded brake lines, that alone makes a big difference.
To do a basic caliper test, get the car off the ground with someone in the car, have them apply the brakes with a minimum amount of pressure, while you rotate the wheels to try & determine if all the wheels have the same resistance to rotation as each other.
It could also be as simple as one caliper not operating as well as the rest, and that could be a problem with the caliper itself or an issue with the brake line to the caliper. If the lines are still the old rubber type replace them with braded brake lines, that alone makes a big difference.
To do a basic caliper test, get the car off the ground with someone in the car, have them apply the brakes with a minimum amount of pressure, while you rotate the wheels to try & determine if all the wheels have the same resistance to rotation as each other.
I replaced all 4 calipers and also did the braided lines, the rear calipers that came with the car are the ones that come with the E- brake , my car has no E-brakePossibly air in the system, easiest test is to pump the brakes several times before applying them, if the car stops better it's likely air in the system.
it could also be as simple as one caliper not operating as well as the rest, and that could be a problem with the caliper itself or an issue with the brake line to the caliper. If the lines are still the old rubber type replace them with braded brake lines, that alone makes a big difference.
To do a basic caliper test, get the car off the ground with someone in the car, have them apply the brakes with a minimum amount of pressure, while you rotate the wheels to try & determine if all the wheels have the same resistance to rotation as each other.
I'm getting confused, your 1st & last posts seem to contradict each other. Either way it sounds like the original issue you had has remained even after you've replaced xyz number of parts.
If you're confident everything you've done so far is good, remove & bench bleed the master cylinder, since you don't know if this was done correctly by the previous owner, you'll then need to re bleed all the calipers again of course, beginning with the longest brake line from the master cylinder.
You may also want to measure the engine vacuum to make sure there's enough vacuum for the booster to operate properly. As a pre check, pump the pedal a few times to get used to the feel, then start the car & feel the brakes again, you should be able to notice the difference the booster is making if it's operating.
If you're confident everything you've done so far is good, remove & bench bleed the master cylinder, since you don't know if this was done correctly by the previous owner, you'll then need to re bleed all the calipers again of course, beginning with the longest brake line from the master cylinder.
You may also want to measure the engine vacuum to make sure there's enough vacuum for the booster to operate properly. As a pre check, pump the pedal a few times to get used to the feel, then start the car & feel the brakes again, you should be able to notice the difference the booster is making if it's operating.
One other thing I just noticed. With that style proportioning valve, you're supposed to use this tool to keep the valve centered when bleeding the brakes. If that tool isn't used the valve can then be off center, which will then restrict brake fluid pressure to either the rear or front brakes until it's re-centered, but not both.
It may be that your booster lacks the capacity you need for the size of vehicle. I had a mini booster (looked like your booster) on my 58 and had the same issues you described. A brake specialist looked at the system and recommended a larger booster to address the problem.
I was thinking that the booster looked smaller than normal, even despite it looking like the 'dual-diaphragm' style. I believe I've also heard that that style does not provide as much assist as the more common large single diaphragm ones.
Thanks for the response, I don’t know much about the booster I have now but what would be a good upgrade booster?
Thanks I will try out that toolOne other thing I just noticed. With that style proportioning valve, you're supposed to use this tool to keep the valve centered when bleeding the brakes. If that tool isn't used the valve can then be off center, which will then restrict brake fluid pressure to either the rear or front brakes until it's re-centered, but not both.
No worries. When you remove the switch use a torch & look down the hole, you should be able to see if it's off center or not, if it is you'll need to re-center it manually with a pick or something similar before you fit the tool & bleed the brakes. One-man bleeders are easy to make if you don't already have one. Good luck.
"Torch" = 🔦, not 🔥 just to keep it safe. lol.
Well, look at that.. I just learned something today. Thanks @Jynx
One other thing I just noticed. With that style proportioning valve, you're supposed to use this tool to keep the valve centered when bleeding the brakes. If that tool isn't used the valve can then be off center, which will then restrict brake fluid pressure to either the rear or front brakes until it's re-centered, but not both.
Bleed the brakesPurchased my 62 lmpala less than a year and it already came with disc brakes front and rear , I noticed that I have to apply firm pressure in order for car to stop, I replaced all the brake pads and bled the brakes but still the same . My pedal does not go all the way down . Goes about half way my only problem is the brakes don’t grab and I have to apply the brakes kind of hard , I don’t know what brand kit this is, any input? View attachment 32041
How much manifold vacuum do you have. My aftermarket disc brakes need a minimum of 14 -15 in. I only make 12-13 in. Which gave me a hard pedal needing a lot of force. I ended up installing a vacuum pump which solved the problem.Purchased my 62 lmpala less than a year and it already came with disc brakes front and rear , I noticed that I have to apply firm pressure in order for car to stop, I replaced all the brake pads and bled the brakes but still the same . My pedal does not go all the way down . Goes about half way my only problem is the brakes don’t grab and I have to apply the brakes kind of hard , I don’t know what brand kit this is, any input? View attachment 32041
Good question, I’m buying a vacuum pump and will check, do you have a part number on the vacuum pump you Installed?How much manifold vacuum do you have. My aftermarket disc brakes need a minimum of 14 -15 in. I only make 12-13 in. Which gave me a hard pedal needing a lot of force. I ended up installing a vacuum pump which solved the problem.
I m trying to bench bleed the master cylinder and I pumped it about 20 times and the rear keeps showing small bubbles while the front doesn’t
Yep, you want no bubbles. If they're very small, the fitting isn't screwed in tight enough on that rear outlet & the air is being drawn in when you release and then pumped out when you compress. You've also got to be very careful with those plastic screws, so tighten a little and then compress a few more times but when you release, release very very slowly, that will help stop air being drawn back in.
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