Page 1 of 1

Bad Brakes

Posted: 03 Oct 2021 15:40
by gleno
Hello Realm,
So my 73 dime has a brake issue, New pads and Shoes, New Master. Yes this has been bleed 3 times no air that I can find.
Any one have I idea on what it may need and how to check?

Thanks

Re: Bad Brakes

Posted: 03 Oct 2021 16:49
by datzenmike
Bad as in a soft pedal???? you don't say what.

Did you bleed the master first?

Re: Bad Brakes

Posted: 03 Oct 2021 18:03
by gleno
Yes sorry Soft pedal and not good stopping power. Blead the master 2 times bench and in car also blead all 4 corners 2 times.

Re: Bad Brakes

Posted: 03 Oct 2021 20:37
by datzenmike
Are the rear drums adjusted? Excessive travel of the shoes will increase pedal travel.

Have you checked the pedal play? Should be 1/16"

Are the flex hoses swelling under pressure?

Re: Bad Brakes

Posted: 03 Oct 2021 22:00
by gleno
Shoes are adjusted to just a bit of drag on the drum. Going to adjust the Rod tomorrow and the lines are new.

Re: Bad Brakes

Posted: 04 Oct 2021 06:25
by datzenmike
Push down on the pedal with thumb. The brake push rod up under the dash should be adjusted so that there's 1/16" to 1/8" or a few mm of easy movement before there is firm resistance.

Re: Bad Brakes

Posted: 04 Oct 2021 10:09
by gleno
I have adjusted this was a little loose, This is a bit better but not great. If I slam them on there is no chance of me locking them up. Could these front calipers be bad? Or is it just non power brakes and im used to these?

Re: Bad Brakes

Posted: 04 Oct 2021 10:26
by bertvorgon
New pads/shoes need to be "bedded" in for a bit. Go out and use the brakes hard for a few stops, let cool down, then repeat.

Possible, the pad material needs to heat cycled a few times.

"Green fade happens when the brake pads release gas trapped in the material. This cushion of gas creates a “hydroplane” effect and reduces friction. Green fade used to be a much bigger issue than it is today. Modern materials and manufacturing techniques have reduced the gas content in brake pad material."

The stock 510 brakes are a LONG way from today's power assisted ones if that is what you are used to.

have the drums been trued up, IE turned. Taper can happen on drums too which does not help.

Re: Bad Brakes

Posted: 04 Oct 2021 21:22
by slowerthantime
Maybe try doing a vacuum bleed. Worked for me when I couldn't get a firm pedal.

Re: Bad Brakes

Posted: 06 Oct 2021 09:58
by RMS
if calipers were bad they would drag or leak. what is your tire size ? anything much bigger than stock wont lock up. if your not pushing your butt into the back of the seat you need to push harder. all my non Datsun owning friends tell me my car has no brakes and I tell them thats why it has gears and a clutch

Re: Bad Brakes

Posted: 06 Oct 2021 17:08
by datzenmike
1/ Safely get up to speed and pull the emergency brake on a few clicks so you can feel the drag. Now try the brakes. Still spongy?

2/
datzenmike wrote: 03 Oct 2021 20:37 Are the flex hoses swelling under pressure?
Look at all of them while someone steps hard on the brake. Do any swell?

3/
gleno wrote: 03 Oct 2021 18:03 Blead the master 2 times bench and in car also blead all 4 corners 2 times.
You opened the two bleeders on the side of the master?

Re: Bad Brakes

Posted: 06 Oct 2021 20:18
by icehouse
front calipers are probably on the wrong sides. bleeder at the top?