320 brakes not working

[Crusty320]

I just replaced the shoes and a cracked brake line in my 320 and can’t get the brakes to work I bled right rear, left rear, passenger, driver, then master cyl. And the brakes never hardened up the pedal can still go to the floor and I’m still getting a large bubble coming up in the master cyl. I’ve tried bleeding them 3 times and no luck. I got no clue what to do I don’t know how to get the bubble out or know where it is. I’m guessing this is a very easy fix and I’m just dumb but help would be greatly appreciated.

[ggzilla]

20 minutes ago, Crusty320 said:

can’t get the brakes to work I bled right rear, left rear, passenger, driver, then master cyl

Always start with the master cylinder. Crack the line where it comes into the master cylinder

[datzenmike]

While the hard line was off the master may have gravity drained and air got into it as well. Not to mention a cracked line would have also let air into the system initially. 

 

I'm assuming you depressed the brake peddle and held it then opened the bleeder and let air out? Then closed the bleeder before letting the brake peddle up? Repeated this as it will take several go rounds till the lines fill up.  Check the master often and keep filled.

[banzai510(hainz)]

i would put my finger over hole inside master and have someone push pedal few times. I use a clear medical plastic line in a clear bottle. I pump the break maxbe 2/3times. Fill .look at line see bubbles come out. Do this on all 4. I just did my 521 like this then it gravity feed out. Seems fine then tighten up the adjusters.

[datzenmike]

Also loosen the emergency brake adjustment before bleeding. When done adjust the wheel cylinders and reset the emergency brake.

[ggzilla]

I finally remembered how I did the master bleeding

 

If an already-installed master cylinder runs dry, bleed it as follows BEFORE bleeding individual wheel cylinders.

1. Top up reservoir with new brake fluid
2. Have assistant pump pedal three times, then hold pressure
3. Crack the fitting slightly for outlet of master cylinder until fluid comes out
4. Tighten fitting
5. Repeat steps until only fluid comes out, and no air spurts out with the fluid

For one-man bleeding I used a brake line stub, fitted it to the master oulet with a length of rubber hose feeding back into the reservoir (with the end under the fluid). I could pump the pedal while watching between the windshield and open hood. Could see the bubbles come out. Then remove the stub line, put a finger over the outlet hold, finally put the brake line back. It worked well, after this any air from the fitting would be bled out at the wheel cylinders

[Crusty320]

So there was a small crack in the line that goes off of the master to the splitter I assume this line is the original one it was so rusted on I used all the chemicals to try and loosen it up and got it off but it stripped the splitter. I can’t really see a problem if size up in line and use a tap on both the splitter and master cylinder. Is that a bad idea or should I try and find a new splitter?
 

[banzai510(hainz)]

i belive its a sae size so should be ez to get spliter

 

[ggzilla]

The 320 splitter is 5-way, the fifth connection is pipe threads for the brake light switch (switch 25320-02700)

 

 

I would try to tap the brake line port, but I don't think there is enough meat to go up a size bigger.

 

Nissan 46234-04100 CONNECTOR-5 WAY

 

[Crusty320]

Good news,I was able to tap it bigger and get it on tight. Bad news I need a new one of theseI’ve replaced one of them already a while ago but I have no clue where I got it or even what to call this.I’ve checked rockauto and didn’t see anything. I believe they are interchangeable up to the 620 but have no clue where to get them.

[datzenmike]

Looks identical to the 521 and the 620 rear.

[ggzilla]

That is a rear wheel cylinder bleeder or as Datsun calls it a "connector" (the bleeder is on one end)

1 hour ago, Crusty320 said:

I need a new one of theseI’ve replaced one of them already a while ago but I have no clue where I got it or even what to call this.I’ve checked rockauto and didn’t see anything. I believe they are interchangeable up to the 620 but have no clue where to get them.

 

Nissan 44133-07200 CONNECTOR with 41128-30001 BLEEDER SCREW

[Crusty320]

I’ve only been able to find one and it’s on eBay for 79 bucks, that’s a little bit pricey for me… I know there gotta be some for sale cheaper but I can’t remember where I found it.

[wayno]

I have a few of these around, but they are not new looking.

[Crusty320]

The reason I figured I need a new bleeder is it was partially stripped where the bleeder screw goes so it would leak from there. I ran a 10mil tap with finer threads so I could just put a slightly bigger screw in  and call it good I bled it and let them sit for a day and it’s leaking out the valve end like it’s not tightening up enough.

[datzenmike]

Doesn't a bleeder screw have a taper at the end that seals just like an engine valve and seat? A screw would rely on the threads making the seal and that just won't work. 

[Crusty320]

You are right but because they were stripped they wouldn’t tighten up to seal. Now I think they aren’t dealing because that taper at the end of the screw isn’t the right size or shape and I need to try other screws.

[Slow Loris]

I can send you an old 521 one if you want. Like Wayno’s, it’s not new but it wasn’t leaking. Bought it with a banjo bolt I needed. 

[banzai510(hainz)]

Use 520/521. 620 is metric. Im not pos if different. Ebay I found nos wheel cyl w those bleeder come w it w banjo washers. Like 45bucks. Get the one from slow loris. The thailand made ones are new but dont come w those y fittings. If rockauto dont show them then u dont get them on cylinders

Edited August 31, 2025 by banzai510(hainz)

[wayno]

I told the author of this thread I would post this photo because I do not know how to post them using URL.

 

[Crusty320]

So my brakes went out again cause why wouldn’t they. I’m done dealing with them so I brought it to the shop and they need to replace most of the brake lines I guess, they said they are so rusted they will leak more than it now is. They can’t find the brake lines they need though, I thought there would be a generic line but I guess not? They asked if I could some I have no clue where to get the lines if there isn’t any generic.

[Crusty320]

Just to be a specific I’m looking for the soft lines like this. Im going to ask around locally but I doubt I will find something 

[ggzilla]

Those are called "brake hoses"

 

The lines are generic nicupro alloy lines,, but the hoses are specific to a vehicle. That being said, you can use new a hose from a different vehicle if it is approximately the same length with the same fittings, perhaps 3/8 inch taper thread or whatever the 320 uses

[Slow Loris]

Pretty sure I got my 521 brake hoses down at Napa, nowhere special. Assuming they are same threading, also probably similar lengths? 

[bilzbobaggins]

Yeah.  Shoud be sae threads.  Id bet 521 ones would fly.