Powermaster issues

[Steve Wood]

Exactly the way to proceed if you want to be exactly exact on your exact car! 

[daveismissing]

Do what Earl said.  If its off a hair it doesn't matter like fitting cove base moldings. That's the way we did things before the internet gurus gave everyone headaches.

My Dad was a carpenter and when you worked for him there was NO "being off a hair" on the cove base mouldings

[Scoobum]

Quote from: ULYCYCDo what Earl said.  If its off a hair it doesn't matter like fitting cove base moldings. That's the way we did things before the internet gurus gave everyone headaches.My Dad was a carpenter and when you worked for him there was NO "being off a hair" on the cove base mouldings

ALEX PLUS All Purpose Acrylic Latex Caulk Plus Silicone (dap.com)

[IL KIM]

Ha ha.

I measured and remeasured, as I like working upside down with my head in the carpet, while it snows outside.  The booster rod has some play and gravity also pulls it down but the exact measurement I came up with for my exact cove-free car Is 1.0000” below the OEM pin!  Actually I think It could be +/- a half inch and be ok.

Thanks for the help. Now where to put the frigging vacuum tee in the exact spot in the PVC line with the fuel rail being in the way of the perfect location, is next. The tee wants be be tight above the pvc but I’m not sure I want the booster source so low and close to the pvc valve (and not where I placed it in these 2 pics).  I’ll figure it out.

[Scoobum]

Sucking oil into the booster...prol ly isn't a good idea. Lots of vacuum pedals for sale on the other board, or you could have posted looking for one on here. Vendors sell a vacuum block to replace the one over the TB for the vacuum conversion.

[IL KIM]

Fuel rail shown.

Yes I share your thoughts Scoobum. I may look for that vacuum block but trying use the parts that came with the kit and understand where the tee was meant to go.

[earlbrown]

Now I see why you were confused about putting the tee in the PCV hose.

That's not a normal 1pc hose. It's something someone 'custom built' in the past with a junction.


As far as sucking oil into the booster, don't worry about it. The throttlebody is the vacuum source that pulls the oil, not the booster.   All the line running to the booster does is supply a signal, not actual flow.

[IL KIM]

Thanks Earl. I did install an 86 engine assembly into my 85 GN around 1990 so it’s quite possible the EGR hose is not stock although I always thought it was OEM with the plastic union connecting the right angle to straight tube.

With the Repeated cycles of vacuum pulling through the PVC hose and boost conditions I was thinking some residual oil could end up eventually in the booster hose. 

I will just get some 11/32 straight vacuum lines and put the tee up high basically replacing the 90 rubber bend, and then in the future get an aluminum vacuum block with extra port.

If anyone has a used vacuum block they want to sell, please let me know.  I may post on TB site but can’t seem to be able to reset my password over there. Keeps saying an email was sent to me and I don’t get the mail.

Thanks all!

[IL KIM]

Does anyone know what the torque spec is for the brake pedal to bracket is?  I’ve googled and search to no avail. Part of me says just snug up the pinch nut but thought I’d ask to be sure. Thanks.

[earlbrown]

It's 'snug up the pinch nut'.

....but not so tight that the pedal can't swing freely.

[IL KIM]

Thanks Earl!  Then I’m done with the conversion:)  Now to swap out the rubber Flex hoses with steel lines and bleed the corners.

[earlbrown]

Just make sure to start at the wheel furthest from the master cylinder and work towards the LF.


..or do, like me and drink 4 beers, put 4 1/4" hoses on each bleed nipple into each can.



The drink the remanding 20 beers until all four hoses run clean.

[IL KIM]

Hello. Thought I would provide an update on my vacuum conversion saga. The Cardone master cylinder leaked out the back between the mc and painted booster as evidenced by attached pic. I got another Cardone 10-1926 from Amazon, again bench bled it and installed it.  The 2 mc’s looked a little different in reservoir color and cap texture and cap tightness and the 2nd one allows better gravity flow to the rear brake port. Guess Cardone rebuilds any mc sent back to them.

The Chinese brass proportioning valve I got from eBay did not allow the brake light on the dash to go off. I had used the bleeder tool in place on the switch so I know I did it trip the valve but the light would not go out. I tried leaving a front bleeder screw open and slowly depressing the pedal to get the valve to shift. Also tried hard pedals but light always stayed on. Tried clamping the metering valve pin in while bleeding rear brakes and still no success with the light. Using a continuity test, I believe the switch was bad as it is made when bearly depressed. I could get the light to go off for a split second, in car, at the end of pedal apply when rebleeding the front corners (Key on/engine off test). So I replaced the prop valve with a different Chinese (Kipa PV2) valve, rebled the system and the light stays off!  Must’ve gone through over 72 Oz of Dot 4 fluid. Gotta love quick Amazon deliveries.

I tested the GN in my driveway today as it was dry out. Brakes feel good but seem less effective then the Powermaster. Trying a panic stop From ~35mph the fronts do lock up when close to full stop, but really have to press hard. Is this typical of the vacuum setup?  Also while idling and pressing the brakes, the idle goes up slightly on apply and also when I release the pedal.  Is this normal?
Just driving this in the driveway felt great, and reminds me why I still own this torque beast!  Puts a smile on my face every time.

And a shout out to Earl for all his help with this. Thank you!

[reality]

https://itstillruns.com/adjust-brake-light-switch-7367033.html

[Steve Wood]

It's not right. Sounds like the check valve in the booster is leaking or perhaps inside the booster.  When you touch the brake and idle speeds up, it sounds like it is sucking air thru the brake hose which leans the engine making the idle go higher.