My 1971 521

[mainer311]

Nice. 

 

I need to get around to doing this. I installed NOS rear leaf bushings this winter on one side, and still haven't even gotten to the other side yet. 

[thisismatt]

Doesn't seem like much grease, but I haven't done these before so I could be wrong 😄

[d.p]

1 hour ago, thisismatt said:

Doesn't seem like much grease, but I haven't done these before so I could be wrong 😄

You and me both.  

[d.p]

Making progress.  
 

just need to make a couple hard lines, hook up the parking brake and bleed these fuckers.  

[mainer311]

It’s nice to see that your balls finally descended.

[gene knight]

4 hours ago, d.p said:

Making progress.  
 

just need to make a couple hard lines, hook up the parking brake and bleed these fuckers.  

d.p :   where did you get the rear disc brake setup?

[d.p]

This man: 

 

https://www.facebook.com/kielbasavw

 

lol to my balls descending. They are so low they hit my knees…..oh wait that’s my dong.  

Edited May 14, 2022 by d.p

[thisismatt]

Is that like "Kyle" or KeyL?

 

Did someone say dong?

[Crashtd420]

14 hours ago, d.p said:

Making progress.  
 

just need to make a couple hard lines, hook up the parking brake and bleed these fuckers.  

Cant tell from the picture are the calipers facing front or back?

What side of the truck is this?

Edited May 14, 2022 by Crashtd420

[Crashtd420]

Oh one other question...

Did you do anything with the master cylinder?

If the master was setup for front disc rear drums you need to swap the residual valve out....

Or remove it and you can add one inline on the brake line....

Discs are only 2lbs 

Drums are 10lb valves..  

[d.p]

Back and that is the passenger side.  What is and where can I get a new residual valve? And what happens if I don’t do anything with it? One half of the parking brake mount because this stupid website complains about file size so much. 

[Crashtd420]

1 hour ago, d.p said:

Back and that is the passenger side.  What is and where can I get a new residual valve? And what happens if I don’t do anything with it? One half of the parking brake mount because this stupid website complains about file size so much. 

I think if you do nothing it's just keeps extra pressure on the pads... 

I'm guessing premature pad wear... 

 

I dont know if you can buy a replacement valve for the master or if you just need to get it from another master cylinder...

I used an inline one from Amazon...

I think stroffgren said it doesnt matter where you put it .. basically just need to be after the master but before the tee that splits the rear...

 

[Crashtd420]

Wilwood Engineering 260-13783 Residual with Fittings (2Lb), Blue https://www.amazon.com/dp/B01GVIM8G8/ref=cm_sw_r_cp_apan_i_D9D1M03A27PM1XX47M5S

[d.p]

I just bought that one. Do I have to remove the one in there now?

[Stoffregen Motorsports]

26 minutes ago, d.p said:

I just bought that one. Do I have to remove the one in there now?

Yes. It should be inside the outlet port on the MC. Usually a small pick will get it out. It can be black or white plastic, or sometimes black rubber.

[Stoffregen Motorsports]

Google "residual valve inside master cylinder" and look at the pics. It can be in various places.

[d.p]

Assuming I would just need to take the one out for the rear reservoir or does a single valve serve the front and back?

[d.p]

Brakes all done except for that valve.  Had to extend the parking brake cleavis way out so I could attach them on both sides.  In the end not so bad except for the axels which cost me $125.  I think all in it was around $500 give or take for everything.  More with the flaring tool and brake line straightener but those don’t count. 
 

 

[mainer311]

The dual-res masters have a residual valve in each outlet. In our case, the front is setup for disc, while the rear is setup for drum. The drum valve needs to be removed, and replaced with the one Neil sent.

[d.p]

6 hours ago, Stoffregen Motorsports said:

Yes. It should be inside the outlet port on the MC. Usually a small pick will get it out. It can be black or white plastic, or sometimes black rubber.

outlet port that goes to the rear brakes?  Meaning where the hard line terminates on the MC? 

[datzenmike]

Disc brake residual valves need about 1/6 the pressure (2 lb.) vs. a drum brake (12 lb.)so it will be like driving around with foot resting on the brake. They are going to get HOT.

 

If this is a Datsun/Nissan master cylinder just ask around for the front residual valve from a spare that someone has. BTW the front circuit is at the rear of the master, rear is at the front. I did this with my 4 wheel disc 15/16" zx master. Put my '76 rear drum residual into it for my rear drums.

 

Don't mix them up  impossible to tell which is which...

 

 

[d.p]

Thanks @datzenmike the rear reservoir outlet is on the front of my master.  I thought I could get the valve out with the master in the truck but it’s tough trying to break that huge nut loose with the column right there. 
 

Guess I’ll just have to pull it tomorrow.  

[d.p]

Oh what do I remove in that pic? Jus the spring and smaller black piece? And if I don’t have any residual valve in that would that be bad? Meaning I remove the 10lb fucker and don’t out 2lb back in or inline somewhere? 

Edited May 15, 2022 by d.p

[d.p]

I read this as well ..

 

”Disk brakes must not use a Residual Valve, but only need a weak pressure which naturally results from the M/C being mounted high on the firewall. However, some all-disc Master Cylinder use a low-pressue check valve, so check the application.”

 

also says “If the RV is left in place, the brakes will still work OK, but will wear faster than normal.”

 

So do I really need any RPV as our masters are high enough up?
 

http://datsun1200.com/modules/mediawiki/index.php?title=Residual_Valve

 

[datzenmike]

I looked back about 4 pages but missed what master you are using so assumed Nissan. Well Nissan saw fit to use a residual valve even on disc brake vehicles. That 2 PSI keeps the pads against the rotor just enough to keep it clean yet produce negligible drag. It it were water, you would need a vertical column 4.6 feet high to get 2 PSI at the bottom. Now brake fluid is lighter than water so it would be even higher. I would run the disc brake residual valve.