Hydroboost conversion driving me crazy (Guru’s?)

Gnx6

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Jun 22, 2003
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For some reason I decided to convert to Hydroboost. I bought the Hydratech setup, wilwood master cyl and also converted to wilwood 4 piston front brakes. I had horrible problems with air but got them resolved. Here is my current issue.

When stepping on the brake firmly my red brake warning light comes on. The switch in the proportioning valve is tripping it. I know that this is usually caused by a difference of pressure between the front and the rears. Brake pedal feel is good with the exception of the light. I have not driven it.

I’m at my witts end with this and not sure where to go from here. Thanks for your input.

 

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No disintegrations

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Dec 27, 2015
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The air could be way up near the master. Crack the line as a helper presses pedal. Then do the other one. Some do the pump it up, hold then crack. I found if there's a ton of air its better to open then press. Maybe just my preference.
 

Gnx6

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Jun 22, 2003
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I did bench bleed the master and did everything mentioned but I will lower the nose of the car so the master is almost level and do the line bleed again.
 

Dhos1

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Apr 14, 2012
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I have the same system and love it. I am in line with what everyone else says and suspect air in the system as it has happened to me.
 

captndave737

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Feb 14, 2006
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Air in the system for sure. You can disconnect the lines from the master and let it gravity bleed for a while. Gotta have something to catch the mess. Then re connect and gravity bleed the wheels for a few hours making sure the reservoir doesn’t get too low.
 

TexasT

Texas, Where are you from
Sep 10, 2002
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original proportioning valve? If so you might consider a new brass replacement. When you are bleeding how are you doing it? I like the old, get a helper, and do the press and hold and the let it back up. I like to put a 2x4 under the pedal as the "assistant" is not always carful not to over stroke the mc. What is coming out of the bleeders? Nice new fluid? If not I'm sure you haven't bled enough. I like a clear glass jar to catch in so I can see what we have and the bubbles and such.
 

Gnx6

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Jun 22, 2003
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I sent Hydratech poctures and a video and they figured it out. The stock system has the front brakes on the rear chamber of the master cyl. The Wilwood is designed to have the front brakes on the front chamber. I had the lines in the incorrect order for this brake system. Flipped the lines and re-bled. No more issues.
 

Chuck Leeper

8/10's of a century!
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May 28, 2001
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Was about to post this^^^^.
On my first install, I got varying "opinions", as to the line location.
A call to WW, and I got the same answer as you did.
Front to ft.
Rear to rear.
 

Boostrules

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Mar 16, 2013
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I sent Hydratech poctures and a video and they figured it out. The stock system has the front brakes on the rear chamber of the master cyl. The Wilwood is designed to have the front brakes on the front chamber. I had the lines in the incorrect order for this brake system. Flipped the lines and re-bled. No more issues.
Thanks for letting us know what resolved the problem. Too many times the post ends with no answer as to what finally fixed their issue.
 
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Gnx6

Member
Jun 22, 2003
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Thanks for letting us know what resolved the problem. Too many times the post ends with no answer as to what finally fixed their issue.
Ya that stuff drives me crazy when searching threads. They either get hijacked and go off topic without resolve or they just go dead. Hopefully it will help someone in the future.
 

TurboTnZ06

Go on red!
May 7, 2002
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Same thing when I converted to hyrdo on a 81 caddy master in my 87, reverse the lines front to back. Othe thing to watch out for on these swaps is reman power steering units may not be reverse units and basically don't work on our cars even though they fit.
 

1KWIKSIX

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Sep 29, 2007
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If you find the front to rear brake bias needs tweaking....do yourself a favour and get Wilwoods Adjustable Proportioning Valve that hangs off the side of the master cylinder. It comes with prebent SS lines and is a bolt on deal.
You will of course need to remove your original G Body brass proportioning valve and re-plumb some brake lines, but will have the ability to adjust brake bias.

Wilwood1.JPG
 
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87national55

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Feb 16, 2007
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If you find the front to rear brake bias needs tweaking....do yourself a favour and get Wilwoods Adjustable Proportioning Valve that hangs off the side of the master cylinder. It comes with prebent SS lines and is a bolt on deal.
You will of course need to remove your original G Body brass proportioning valve and re-plumb some brake lines, but will have the ability to adjust brake bias.

View attachment 335860
How much was the entire set up? I want the same thing.


Sent from my iPhone using Tapatalk
 

1KWIKSIX

Well-Known Member
Sep 29, 2007
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It's not an inexpensive undertaking.
Think I'm into it for the Wilwood stuff for close to 1 grand +/- $
Don't forget to add in the cost of The PSC Power Steering Fluid Reservoir , Modified PS Pump for Higher Pressures needed for HydroBoost from Sweet Mfg, De Rale Power Steering Cooler, extra AN fittings & lines etc, it all adds up.
Glad that I was able to perform the change over and brake work needed on my own.


Here's a link:
https://www.tallonhydraulics.com/store/index.php?main_page=index&cPath=54_76

& the adjustable proportioning valve was extra $
I got them both from Butch as Talon Hydraulics (now Vintage Speed Reaper)

https://www.tallonhydraulics.com/store/index.php?main_page=index&cPath=54_76

A small price to pay for your safety!
Hands down best braking I've ever experienced. :)
 
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