Hydroboost conclusion

BlackMetal

Active Member
Joined
Sep 29, 2005
So after bench bleeding the master cylinder, I finally got some pedal feel. I started the car today, pressed the brake pedal a couple of times, and the brake light on the dash finally went out. I'm guessing there was air down at the proportioning valve and finally having a functioning master cylinder was able to push it out.

Pedal still wasn't as great as I hoped, but after driving around and stopping for gas, the pedal started to feel better. Maybe the power steering just needed to purge some air, but whatever it was, the pedal is now solid. Almost harder than I expected, spent a few minutes wondering if I was even getting power assist because the pedal is so firm, but I think I'm just not used to ever driving this car with a pedal that doesn't feel like a dish sponge.

For the first time ever I can stop this car hard enough to actually make the front end dive. :eek:

I'm glad I was able to drive it today, I took it to the performance shop where I'm trying to get hired and tried to win some bonus points with the car. They said I'd know by the end of the day.

Thank you to....
jdpolzin - Told me where I could find the 85 hydroboost parts for the conversion. Answered countless PMs containing many stupid questions. Helped me through the entire thing.
Blazer406 - For suggesting the method of splicing into the 87 hardline when I wasn't able to get the 85 line to work. Also answered a bunch of questions I had.
DougsfastZ - Your thread from 2008 with details and pictures of the install was a big help. Always great when someone takes the time to create a guide like that.
And anyone else who answered my questions in the various threads.

The worst part was working on the brake pedal under the dash. I had the front seat out and anyone who can fit in there with the seat still in place is crazy!

Very grateful for all the help I received, I never would have done this on my own. In return I can simply offer to help the next brave soul that decides to do the swap. The first time was definitely tough. I feel like I could do it again in 60 minutes.

Who wants to see a pretty picture?
pmaster.gif
 
Glad to help brotha! Now part that PowerMaster out and get your money back for what you spent on the HydroBoost!
 
Glad to help brotha! Now part that PowerMaster out and get your money back for what you spent on the HydroBoost!

Probably throwing it in storage for the day I need to turn everything back to stock, even though I never plan on that. :tongue:

And to clarify my comment about the 85 line not working, I do now see how you could make it work. So yes, for anyone considering it, you can make it work with the stock 85 lines. Do not attach the end to the booster first. :rolleyes:
 
My install was a PITA as well.......working on the pedal was certainly heinous. Overall the conversion is towards the top of my list for the best money I spent. Glad you finally got it going!
 
is there an aluminum m/c that works on 85 hydroboost systems? all i seem to find is cast iron :(
 
OK it has been a while since I have been on here. A few years actually. I haved noticed this new brake upgrade. I know I will eventually have to do this but, what happened to the vacuum brake upgrade that used to be so popular?

I have seen these hydraboosters for years. I work on vehicles for the Army. They are on every light wheeled vehicle that the military has. Does anyone have a part# off of these that are being used? The master cylinder looks different though. I wonder what vehicle this is off of.

Just tryin to catch up.
 
pics..............:)

Anything specific you want to see?

OK it has been a while since I have been on here. A few years actually. I haved noticed this new brake upgrade. I know I will eventually have to do this but, what happened to the vacuum brake upgrade that used to be so popular?

I have seen these hydraboosters for years. I work on vehicles for the Army. They are on every light wheeled vehicle that the military has. Does anyone have a part# off of these that are being used? The master cylinder looks different though. I wonder what vehicle this is off of.

Just tryin to catch up.

The vacuum conversion is still fairly popular. I'd say vacuum is more of a step sideways from the Powermaster than it is a true upgrade. With vacuum not being an electrical assist, you no longer have to worry about the 30amp fuse blowing and losing your brakes. You don't have to maintain the PowerMaster with all the bizarre parts and peices that are getting more expensive to replace. But as far as actual braking power, some people can barely hold any boost with their vacuum brakes. There are check-valves and diaphragms that can fail in the vacuum system.

Hydroboost is an upgrade in the truest sense of the word because it can't be beat for actual clamping force at the calipers.

You can do the conversion with parts from an 84/85 Grand National where the Hydroboost came stock. These parts are getting harder to find though. You can also get hydroboost units off of Chevy Astro vans but it requires more fabrication to get them bolted up to our cars. The A-1 Cardone part number for the reman brake booster is 10-1984.
 
Thanks metal. I can add from my own experience that this hydrabooster is very durable. very rarely do they fail. I think I have replaced 4 in over 20 years.

My GN is just for street but, I know if I put this on I will be able to forget about it for as long as I own the car.

I need to ask. Where can these be purchased? And what was your turn-key dollar amount for install? I need to do it as my powermaster is failing.

Thx in advance.
 
Oops, 10-1984 is the part # for the MASTER CYLINDER, not the booster. Disregard that.

I'll PM you about the rest.
 
.......snip......Where can these be purchased? And what was your turn-key dollar amount for install? I need to do it as my powermaster is failing.

Thx in advance.

I really poor-boy'd my conversion.....

Got 3 hydroboost systems out of the junkyard one Saturday..... average price of the three was around $30. (friends ended up with the other two) I bought 2 stock hoses for an '85 GN with hydroboost.... and spliced the line coming off the '87 PS pump... into the stock '85 line... the other was bolt-in. I also just tee'd into the drain line. I probably have less than $130 or so in my conversion.... I did all fab myself.

I have sold my accumulator off my PM for $75.

So.... I'm out of (less than) $55 right now.... and it works great.

I do plan on taking the conversion one step further with a different plate so I can use an unmodified hydroboost assembly off an Astro Van in case it ever goes out.... shouldn't be a problem to get...
 
I'm so glad you got it to work finally...

I hate you had issues....

FWIW... I did mine w/o removing the seat... and I'm 250 # ... easy.... It was a PITA. I managed.... I just leaned it back all the way...
 
I really poor-boy'd my conversion.....

Got 3 hydroboost systems out of the junkyard one Saturday..... average price of the three was around $30. (friends ended up with the other two) I bought 2 stock hoses for an '85 GN with hydroboost.... and spliced the line coming off the '87 PS pump... into the stock '85 line... the other was bolt-in. I also just tee'd into the drain line. I probably have less than $130 or so in my conversion.... I did all fab myself.

I have sold my accumulator off my PM for $75.

So.... I'm out of (less than) $55 right now.... and it works great.

I do plan on taking the conversion one step further with a different plate so I can use an unmodified hydroboost assembly off an Astro Van in case it ever goes out.... shouldn't be a problem to get...

Sounds like you got yourself a good deal there.

Do you know if anyone has tried a hydraboost from a GM or chevy truck with a 6.2 diesel?

Just curious.
 
Sounds like you got yourself a good deal there.

Do you know if anyone has tried a hydraboost from a GM or chevy truck with a 6.2 diesel?

Just curious.

It should work just fine. I have 150.00 in my set up and I had customer lines made through NAPA. IMO same money as the vacuum, but twice the brakes. If you can fab anything you can make these work. Pretty simple and straight forward!
 
Black Metal, good job!!!! The best mode I think I have ever made, so much nicer to drive now!
 
Top