320 rear brake proportioner

[Crusty320]

I haven’t had luck finding any proportioners that would work on the 320 I hope to have this truck done before winter fully hits and this is the last part I need (hopefully) any help is greatly appreciated 

[Stoffregen Motorsports]

Proportioning valve?

 

Get a Wilwood unit, which takes an hour to install, and be done with it.

 

https://www.summitracing.com/parts/wil-260-10922

 

[Stoffregen Motorsports]

They also make one with a built in tee (for front brakes) and a brake light switch.

 

https://www.summitracing.com/parts/wil-260-11179

 

[Crusty320]

1 hour ago, Stoffregen Motorsports said:

Proportioning valve?

 

Get a Wilwood unit, which takes an hour to install, and be done with it.

 

https://www.summitracing.com/parts/wil-260-10922

 

This will work on the rear brakes for the 320?

[Stoffregen Motorsports]

Yes.

 

It will come with instructions, but to be clear,maybe you should google "wilwood brake proportioning valve install" ahead of time to be sure.

[Crusty320]

Thank you definitely gonna look for a video so I don’t break more stuff while installing it 

[datzenmike]

Better check first. I think Nissan just designed the front rear bias into the vehicle. By simply using a smaller wheel cylinder the rears are less effective when braking.

[Stoffregen Motorsports]

I don't even know why he needs one, Mike. I just figured I'd point him in the right direction. Maybe he's installing a dual circuit master?

[datzenmike]

I don't know for sure, I don't think the 510 has one. Guessing the 320 doesn't. Anything with a dual master is easier to bias the front brakes.

 

I've used one of the wilwood valves on my 620. It had 16" of lift and it was impossible to stop rear wheel lock up. 

[Stoffregen Motorsports]

17 hours ago, datzenmike said:

I don't know for sure, I don't think the 510 has one. Guessing the 320 doesn't. Anything with a dual master is easier to bias the front brakes.

 

I've used one of the wilwood valves on my 620. It had 16" of lift and it was impossible to stop rear wheel lock up. 

That's because of the massive lift and all that weight transfer.

 

The 320 has a single circuit master. Converting to a dual circuit master is not only safer, but makes it easier to tun the bias. It's easy enough to fit a 620 master, but the hole in the firewall is a tad too small, so you have to grind it larger with a carbide burr, or whatever.

[Crusty320]

I don’t know what any of that means but i was wrong about the part is needed it was really a rear cylinder pressure valve that was needed, i was able to get one with some help from a freind we found  a guy on ebay selling some. thanks for the help though.

Edited November 22, 2023 by Crusty320

[Crusty320]

I didn’t think I would have to come back to this tread but I keep finding stuff wrong with the brakes. I need a new master cylinder. And if what Mike said is true then I would prefer one that is close in size to the original if you know where I can find one that would be great.

thanks, crusty

[datzenmike]

On 11/22/2023 at 11:58 AM, Crusty320 said:

I don’t know what any of that means but i was wrong about the part is needed it was really a rear cylinder pressure valve that was needed, i was able to get one with some help from a freind we found  a guy on ebay selling some. thanks for the help though.

 

This is likely the pressure valve that turns on the rear brake lights rather than the later switch on the pedal..

[Crusty320]

1 hour ago, datzenmike said:

 

This is likely the pressure valve that turns on the rear brake lights rather than the later switch on the pedal..

The problem is that even when the brakes have been bled I have to pump the brakes to get air out of the lines and then stop so I’m thinking it’s the cylinder cause when I bled that some rust came out

[Stoffregen Motorsports]

Hydraulic cylinders aren't usually "going bad", except when they have a buildup of junk in them. If they are clean and the seals are good, they should be good enough to use.

 

I suspect it's an adjustment issue you are having. There is no mystery in a single circuit brake system so double check that the shoes are adjusted properly, and that the pushrod is adjusted at the master cylinder (1/16" end play, no more, no less). And try it again.

 

If you're using any contraption to bleed the brakes, ditch that and go for the two person pump/hold method.

 

If one or more cylinders is not releasing fluid when the bleeder is cracked open, try filling the master and opening that bleeder and letting it gravity bleed for a while. You should see the fluid drop in the reservoir. If it isn't dropping, try pushing the pedal back and forth VERY SLOWLY to get fluid moving, then close it up and try again.

[Crusty320]

just got to make sure I’m right the red arrow is pointing to the clutch reservoir and the black to the brake reservoir, is the reservoir also the master cylinder like that whole metal thing? I know this is a dumb question but I’m not the smartest 

 

thanks, crusty

 

Edited December 11, 2023 by Crusty320

[datzenmike]

Black brake Red clutch

[Crusty320]

1 hour ago, datzenmike said:

Black brake Red clutch

And the black is in fact the master cylinder right? 

[datzenmike]

The large round tops are the reservoirs that hold the brake fluid. The aluminum body below it is the actual master cylinder.

 

Something like this...

 

 

The reservoirs differ but basically this. The right side linkage connects to your brake pedal and it pushes a piston forward which pushes brake fluid under pressure into the brake lines which in turn push the brake shoes against the drums to stop. When the brake is released the springs retract the brake shoes and push the brake fluid back into the reservoir.

[Crusty320]

Ok, do you know of any cylinders that would work well with the 320?

[datzenmike]

There are several single cylinder masters used on Datsuns.

 

1/ Look on the side of your master for the diameter size... possibly 5/8" or something else.

 

2/ Also is there any electrical wires to the master? Some had a pressure switch to activate the rear brake lights.