Subject: Re: [Roadsters] Rx7 rear end issues ...edited

From: "Tim . via Datsun-roadsters" <[email-masked]>
Date: Tue, 23 Sep 2025 11:08:55 +0000

--===============3400878960057514721==
Content-Language: en-US
	boundary="_000_MN2PR14MB2862A304A2077B269F85F766B41DAMN2PR14MB2862namp_"

--_000_MN2PR14MB2862A304A2077B269F85F766B41DAMN2PR14MB2862namp_
Content-Transfer-Encoding: quoted-printable

If this was actually too much pressure in the line not being released, woul=
dn't one expect both rear brakes to be affected?

In my case, only the RR is rubbing. Also, I ran the caliper piston all the =
way back in and have not touched the brake pedal at all.

tim
________________________________
From: futofab <[email-masked]>
Sent: Wednesday, September 17, 2025 7:04 AM
To: Tim . <[email-masked]>; Datsun Roadster List <datsun-roa=
[email-masked]>
Subject: Re: [Roadsters] Rx7 rear end issues ...edited

Check your master cylinder. The large nut on the underside of the duplex br=
ake master, where the brake line attaches, houses a pressure releif valve.

If you have a pressure relief valve for the drum rear brakes, they will mai=
ntain about 10psi line pressure when the brakes are released. This may be c=
ausing the pads to stay in contact with the rotor.

This is something the 510 owners deal with when converting to rear disc bra=
kes. Typically they remove it or swap in one from the front disc brake circ=
uit which is 2psi.

On 510 disc brake swaps, the brake master from a 79-80? 280ZX is typically =
used as it is for 4 wheel disc brakes.

Dave Patten
Futofab LLC

Sent from my U.S.Cellular=A9 Smartphone

-------- Original message --------
From: "Tim . via Datsun-roadsters" <[email-masked]>
Date: 9/16/25 6:55 PM (GMT-05:00)
To: Datsun Roadster List <[email-masked]>, "Tim ." <tims_d=
[email-masked]>
Subject: Re: [Roadsters] Rx7 rear end issues ...edited

I believe I have the rear end from an 82-83 Rx7 with disc brakes and LSD.

I re-built my drive shaft and got rid of the noise I heard with no wheels o=
r brakes mounted (and the car running in gear). Third member bearings and a=
xle bearings spin nice and smooth. I've been told that the axle bearings we=
re replaced by the person who customized this rear end for the Roadster.

With the car on jack stands, I re-assembled the brakes, hung the wheels and=
 ran the car (still on jack stands). I immediately heard a rubbing noise co=
ming from the RR. The noise went away at higher RPMs but there was still so=
mething rubbing that caused the rotor to get so hot I could smell it.

Pulled the wheel back off. Brake pads have a little play as does the part o=
f the assembly that holds the piston. Nothing appears to be binding and not=
hing is sloppy loose.

Parking brake assembly is (basically hanging) loose and does not appear to =
be applying pressure to the pads.

WTF am I missing?

Thanks

--_000_MN2PR14MB2862A304A2077B269F85F766B41DAMN2PR14MB2862namp_
Content-Transfer-Encoding: quoted-printable

<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Diso-8859-=
1">
<style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo=
ttom:0;} </style>
</head>
<body dir=3D"ltr">
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
 color: rgb(0, 0, 0);" class=3D"elementToProof">
If this was actually too much pressure in the line not being released, woul=
dn't one expect both rear brakes to be affected?</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
 color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
 color: rgb(0, 0, 0);" class=3D"elementToProof">
In my case, only the RR is rubbing. Also, I ran the caliper piston all the =
way back in and have not touched the brake pedal at all.</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
 color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;=
 color: rgb(0, 0, 0);" class=3D"elementToProof">
tim</div>
<div id=3D"appendonsend"></div>
<hr style=3D"display:inline-block;width:98%" tabindex=3D"-1">
<div id=3D"divRplyFwdMsg" dir=3D"ltr"><font face=3D"Calibri, sans-serif" st=
yle=3D"font-size:11pt" color=3D"#000000"><b>From:</b> futofab &lt;futofab@g=
sinet.net&gt;<br>
<b>Sent:</b> Wednesday, September 17, 2025 7:04 AM<br>
<b>To:</b> Tim . &lt;[email-masked]&gt;; Datsun Roadster Lis=
t &lt;[email-masked]&gt;<br>
<b>Subject:</b> Re: [Roadsters] Rx7 rear end issues ...edited</font>
<div>&nbsp;</div>
</div>
<div dir=3D"auto">
<div dir=3D"auto">Check your master cylinder. The large nut on the undersid=
e of the duplex brake master, where the brake line attaches, houses a press=
ure releif valve.&nbsp;</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">If you have a pressure relief valve for the drum rear bra=
kes, they will maintain about 10psi line pressure when the brakes are relea=
sed. This may be causing the pads to stay in contact with the rotor.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">This is something the 510 owners deal with when convertin=
g to rear disc brakes. Typically they remove it or swap in one from the fro=
nt disc brake circuit which is 2psi.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">On 510 disc brake swaps, the brake master from a 79-80? 2=
80ZX is typically used as it is for 4 wheel disc brakes.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">Dave Patten&nbsp;</div>
<div dir=3D"auto">Futofab LLC&nbsp;</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto"><br>
</div>
<div id=3D"x_composer_signature" dir=3D"auto">
<div dir=3D"auto" style=3D"font-size:14px; color:#909090">Sent from my U.S.=
Cellular=A9 Smartphone</div>
</div>
<div dir=3D"auto"><br>
</div>
<div><br>
</div>
<div align=3D"left" dir=3D"auto" style=3D"font-size:100%; color:#000000">
<div>-------- Original message --------</div>
<div>From: &quot;Tim . via Datsun-roadsters&quot; &lt;datsun-roadsters@auto=
x.team.net&gt; </div>
<div>Date: 9/16/25 6:55 PM (GMT-05:00) </div>
<div>To: Datsun Roadster List &lt;[email-masked]&gt;, &quo=
t;Tim .&quot; &lt;[email-masked]&gt;
</div>
<div>Subject: Re: [Roadsters] Rx7 rear end issues ...edited </div>
<div><br>
</div>
</div>
<div id=3D"x_appendonsend"></div>
<div id=3D"x_divRplyFwdMsg">
<div style=3D"direction:ltr">&nbsp;</div>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
I believe I have the rear end from an 82-83 Rx7 with disc brakes and LSD.</=
div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
I re-built my drive shaft and got rid of the noise I heard with no wheels o=
r brakes mounted (and the car running in gear). Third member bearings and a=
xle bearings spin nice and smooth. I've been told that the axle bearings we=
re replaced by the person who customized
 this rear end for the Roadster.</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div class=3D"x_elementToProof" style=3D"direction:ltr; font-family:Calibri=
,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
With the car on jack stands, I re-assembled the brakes, hung the wheels and=
 ran the car (still on jack stands). I immediately heard a rubbing noise co=
ming from the RR. The noise went away at higher RPMs but there was still so=
mething rubbing that caused the
 rotor to get so hot I could smell it.</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
Pulled the wheel back off. Brake pads have a little play as does the part o=
f the assembly that holds the piston. Nothing appears to be binding and not=
hing is sloppy loose.</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
Parking brake assembly is (basically hanging) loose and does not appear to =
be applying pressure to the pads.</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
WTF am I missing?</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr; font-family:Calibri,Helvetica,sans-serif; font=
-size:12pt; color:rgb(0,0,0)">
Thanks</div>
</div>
</body>
</html>

--_000_MN2PR14MB2862A304A2077B269F85F766B41DAMN2PR14MB2862namp_--

--===============3400878960057514721==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

________________________________________

[email-masked]

Archive: http://www.team.net/pipermail/datsun-roadsters http://autox.team.net/archive

Unsubscribe: http://autox.team.net/mailman/options/datsun-roadsters/[email-masked]

--===============3400878960057514721==--

---

From: Joseph Berkenbile via Datsun-roadsters <[email-masked]>
Date: Tue, 23 Sep 2025 07:59:45 -0400

--===============1424024515208651427==

--000000000000cd56f4063f76ac81
Content-Transfer-Encoding: quoted-printable

Also check the rubber brake hose going to the wheel. Take the hose off and
blow through it both ways. I had a hose that delaminated inside,
effectively turning it into a one way valve.

On Tue, Sep 23, 2025, 7:26=E2=80=AFAM Tim . via Datsun-roadsters <
[email-masked]> wrote:

> If this was actually too much pressure in the line not being released,
> wouldn't one expect both rear brakes to be affected?
>
> In my case, only the RR is rubbing. Also, I ran the caliper piston all th=
e
> ------------------------------
> *From:* futofab <[email-masked]>
> *Sent:* Wednesday, September 17, 2025 7:04 AM
> *To:* Tim . <[email-masked]>; Datsun Roadster List <
> [email-masked]>
> *Subject:* Re: [Roadsters] Rx7 rear end issues ...edited
>
> Check your master cylinder. The large nut on the underside of the duplex
> brake master, where the brake line attaches, houses a pressure releif
> valve.
>
> If you have a pressure relief valve for the drum rear brakes, they will
> maintain about 10psi line pressure when the brakes are released. This may
> be causing the pads to stay in contact with the rotor.
>
> This is something the 510 owners deal with when converting to rear disc
> brakes. Typically they remove it or swap in one from the front disc brake
> circuit which is 2psi.
>
> On 510 disc brake swaps, the brake master from a 79-80? 280ZX is typicall=
y
> Sent from my U.S.Cellular=C2=A9 Smartphone
>
>
> To: Datsun Roadster List <[email-masked]>, "Tim ." <
> [email-masked]>
> I re-built my drive shaft and got rid of the noise I heard with no wheels
> or brakes mounted (and the car running in gear). Third member bearings an=
d
> axle bearings spin nice and smooth. I've been told that the axle bearings
> were replaced by the person who customized this rear end for the Roadster=
.
>
> With the car on jack stands, I re-assembled the brakes, hung the wheels
> and ran the car (still on jack stands). I immediately heard a rubbing noi=
se
> coming from the RR. The noise went away at higher RPMs but there was stil=
l
> something rubbing that caused the rotor to get so hot I could smell it.
>
> Pulled the wheel back off. Brake pads have a little play as does the part
> of the assembly that holds the piston. Nothing appears to be binding and
> nothing is sloppy loose.
>
> Parking brake assembly is (basically hanging) loose and does not appear t=
o
> Donate: http://www.team.net/donate.html
> Unsubscribe:
> http://autox.team.net/mailman/options/datsun-roadsters/redroadsterman@gma=
il.com

--000000000000cd56f4063f76ac81
Content-Transfer-Encoding: quoted-printable

<div dir=3D"auto">Also check the rubber brake hose going to the wheel. Take=
 the hose off and blow through it both ways. I had a hose that delaminated =
inside, effectively turning it into a one way valve.</div><br><div class=3D=
"gmail_quote gmail_quote_container"><div dir=3D"ltr" class=3D"gmail_attr">O=
n Tue, Sep 23, 2025, 7:26=E2=80=AFAM Tim . via Datsun-roadsters &lt;<a href=
=3D"mailto:[email-masked]">[email-masked]=
</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:=
0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

<div dir=3D"ltr">
<div style=3D"font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color=
:rgb(0,0,0)">
If this was actually too much pressure in the line not being released, woul=
dn&#39;t one expect both rear brakes to be affected?</div>
<div style=3D"font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color=
:rgb(0,0,0)">
<br>
</div>
<div style=3D"font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color=
:rgb(0,0,0)">
In my case, only the RR is rubbing. Also, I ran the caliper piston all the =
way back in and have not touched the brake pedal at all.</div>
<div style=3D"font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color=
:rgb(0,0,0)">
<br>
</div>
<div style=3D"font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color=
:rgb(0,0,0)">
tim</div>
<div id=3D"m_-6037608654467475522appendonsend"></div>
<hr style=3D"display:inline-block;width:98%">
<div id=3D"m_-6037608654467475522divRplyFwdMsg" dir=3D"ltr"><font face=3D"C=
alibri, sans-serif" style=3D"font-size:11pt" color=3D"#000000"><b>From:</b>=
 futofab &lt;<a href=3D"mailto:[email-masked]" target=3D"_blank" rel=3D=
"noreferrer">[email-masked]</a>&gt;<br>
<b>Sent:</b> Wednesday, September 17, 2025 7:04 AM<br>
<b>To:</b> Tim . &lt;<a href=3D"mailto:[email-masked]" targe=
t=3D"_blank" rel=3D"noreferrer">[email-masked]</a>&gt;; Dats=
un Roadster List &lt;<a href=3D"mailto:[email-masked]" tar=
get=3D"_blank" rel=3D"noreferrer">[email-masked]</a>&gt;<b=
r>
<b>Subject:</b> Re: [Roadsters] Rx7 rear end issues ...edited</font>
<div>=C2=A0</div>
</div>
<div dir=3D"auto">
<div dir=3D"auto">Check your master cylinder. The large nut on the undersid=
e of the duplex brake master, where the brake line attaches, houses a press=
ure releif valve.=C2=A0</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">If you have a pressure relief valve for the drum rear bra=
kes, they will maintain about 10psi line pressure when the brakes are relea=
sed. This may be causing the pads to stay in contact with the rotor.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">This is something the 510 owners deal with when convertin=
g to rear disc brakes. Typically they remove it or swap in one from the fro=
nt disc brake circuit which is 2psi.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">On 510 disc brake swaps, the brake master from a 79-80? 2=
80ZX is typically used as it is for 4 wheel disc brakes.</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto">Dave Patten=C2=A0</div>
<div dir=3D"auto">Futofab LLC=C2=A0</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto"><br>
</div>
<div dir=3D"auto"><br>
</div>
<div id=3D"m_-6037608654467475522x_composer_signature" dir=3D"auto">
<div dir=3D"auto" style=3D"font-size:14px;color:#909090">Sent from my U.S.C=
ellular=C2=A9 Smartphone</div>
</div>
<div dir=3D"auto"><br>
</div>
<div><br>
</div>
<div align=3D"left" dir=3D"auto" style=3D"font-size:100%;color:#000000">
<div>-------- Original message --------</div>
<div>From: &quot;Tim . via Datsun-roadsters&quot; &lt;<a href=3D"mailto:dat=
[email-masked]" target=3D"_blank" rel=3D"noreferrer">datsun-r=
[email-masked]</a>&gt; </div>
<div>Date: 9/16/25 6:55 PM (GMT-05:00) </div>
<div>To: Datsun Roadster List &lt;<a href=3D"mailto:datsun-roadsters@autox.=
team.net" target=3D"_blank" rel=3D"noreferrer">[email-masked].=
net</a>&gt;, &quot;Tim .&quot; &lt;<a href=3D"mailto:tims_datsun_stuff@outl=
ook.com" target=3D"_blank" rel=3D"noreferrer">[email-masked]=
</a>&gt;
</div>
<div>Subject: Re: [Roadsters] Rx7 rear end issues ...edited </div>
<div><br>
</div>
</div>
<div id=3D"m_-6037608654467475522x_appendonsend"></div>
<div id=3D"m_-6037608654467475522x_divRplyFwdMsg">
<div style=3D"direction:ltr">=C2=A0</div>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
I believe I have the rear end from an 82-83 Rx7 with disc brakes and LSD.</=
div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
I re-built my drive shaft and got rid of the noise I heard with no wheels o=
r brakes mounted (and the car running in gear). Third member bearings and a=
xle bearings spin nice and smooth. I&#39;ve been told that the axle bearing=
s were replaced by the person who customized
 this rear end for the Roadster.</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
With the car on jack stands, I re-assembled the brakes, hung the wheels and=
 ran the car (still on jack stands). I immediately heard a rubbing noise co=
ming from the RR. The noise went away at higher RPMs but there was still so=
mething rubbing that caused the
 rotor to get so hot I could smell it.</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
Pulled the wheel back off. Brake pads have a little play as does the part o=
f the assembly that holds the piston. Nothing appears to be binding and not=
hing is sloppy loose.</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
Parking brake assembly is (basically hanging) loose and does not appear to =
be applying pressure to the pads.</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
WTF am I missing?</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style=3D"direction:ltr;font-family:Calibri,Helvetica,sans-serif;font-s=
ize:12pt;color:rgb(0,0,0)">
Thanks</div>
</div>
</div>

________________________________________<br>
<br>
<a href=3D"mailto:[email-masked]" target=3D"_blank" rel=3D=
"noreferrer">[email-masked]</a><br>
<br>
errer" target=3D"_blank">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://www.team.net/pipermail/datsun-roadsters" rel=3D"=
noreferrer noreferrer" target=3D"_blank">http://www.team.net/pipermail/dats=
un-roadsters</a> <a href=3D"http://autox.team.net/archive" rel=3D"noreferre=
r noreferrer" target=3D"_blank">http://autox.team.net/archive</a><br>
<br>
Unsubscribe: <a href=3D"http://autox.team.net/mailman/options/datsun-roadst=
ers/[email-masked]" rel=3D"noreferrer noreferrer" target=3D"_blan=
k">http://autox.team.net/mailman/options/datsun-roadsters/redroadsterman@gm=
ail.com</a><br>
<br>
<br>
</blockquote></div>

--000000000000cd56f4063f76ac81--

--===============1424024515208651427==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============1424024515208651427==--

---

From: Charles Hubbard via Datsun-roadsters <[email-masked]>
Date: Tue, 23 Sep 2025 20:54:41 +0000

--===============6275330959635563280==
Content-Language: en-US
	boundary="_000_5E192957BDC9445B98E50B790D844104hubcocom_"

--_000_5E192957BDC9445B98E50B790D844104hubcocom_
Content-Transfer-Encoding: base64

--_000_5E192957BDC9445B98E50B790D844104hubcocom_
Content-Transfer-Encoding: base64

--_000_5E192957BDC9445B98E50B790D844104hubcocom_--

--===============6275330959635563280==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============6275330959635563280==--