Hydraboost question......

JPhil

Huh?
Joined
Mar 26, 2008
Messages
1,361
Location
Loveland, Colorado, USA
I'm seriously thinking of installing a hydraboost brake booster "while I'm at it" this winter. The main reason is just to get that dam big-ass vacuum booster out of there so I can access #7 plug without having to jack up the car to get to it from underneath, plus have some more working room in that corner of the engine bay. I don't need it for low vacuum reasons, although I wouldn't mind removing another potential vacuum leak source.

I understand full well it does not change the physics of how well the car stops, that is the relationships of tire traction and rotor friction and moving mass. It is only a change in method and amount of pedal to master cylinder leverage enhancement.

I'm not really dissatisfied with my vacuum brakes, although sometimes I wonder just how much boost I'm actually getting, as heavy as they feel. I have never locked up the brakes, even in my hardest stops. (Although I never have had to make a full on panic stop yet, either.)

I've read lots of articles & posts, and one of my final questions now is "How does the pedal feel compared to vacuum?"

The believers all say "It's great!" "It's wonderful!" "It stops better than ever before!" "It stops on a dime!" "You'll be smacking the steering wheel with your face it stops so fast!" "It'll lock 'em up like nothing!" etc. Those comments are all so generically subjective they give no information other than, "OK, so you're sold on it."

My question is, how does the feel compare to vacuum boost? Is it more solid? Is it a whole lot more sensitive? Is it touchy? How is the feedback? I understand I'll have to get used to it, but will it make the brake application disproportionally 'light' to how 'heavy' the rest of the car is to operate? I don't really want to have to worry about "locking 'em up" in a situation where I'm not expecting it, either. Locked up brakes are a crash about to happen.

I've even considered changing it out to manual brakes, but if my brakes are as heavy to operate as they are under a hard stop with power assist, boy, they'd be really heavy without it.

I've been back and forth on this for years, but if I'm going to do it now is the time.

Gene, you want to go first? :crylol::D
 
Ok I go 3-4th......All I can say is that I finally put O ring pistons and eliminated the silly springs, put on new lines and got rid of that brake switch up front, caught mine letting air into the front brake lines....So after all that crap and master cylinders, trying to get some 'pedal' on the thing I went HB, and cured my soft pedal.....the damn thing was possible to shove the pedal to the floor, way past were the car would stop reliably, just that I hated that ~4" of pedal travel, plus being 6'5" I shoved the lower firewall forward, and glassed it in, picking up 3" of extra room to lower/bend the gas and brake metal to effectively move the pedals forward, that got my knees off the damn steering wheel....HB most definately stops the car with 2" of travel, and the pedal can NOT go to the floor.....best damn brakes ever on any GM vehicle for 50 years......
 
I've installed the hydro-beast in my 70. I haven't yet driven the car.

From what I've read for the hydroboost to operate properly, the return low pressure hydraulic line must have NO back pressure. GM sells a PS pump made for vehicles equipped with the hydroboost. The PS pump has TWO low pressure return lines...one for the Power Steering and the other for the hydroboost. The low pressure return line for the hydroboost was specifically chosen as to it's location....it's a less backpressure location than the power steering low pressure return. To locate the hydroboost return line into the Saginaw PS pump, a plexiglass model of the pump was built so that flow patterns could be seen to verify no backpressure. I can send you the PS pump part number. A complete new PS pump with the proper hydraulic lines can be bought for about $90 I think.. rockauto.com

Going to remove the factory vacuum canister assembly from the firewall are we???? Prepare yourself for a lot of fun. Of course you'll remove the driver's seat to try to get access. You'll need a long entension and a U joint drive to get at the nuts on the drivers side of the firewall. One nut is extremely difficult to remove. Also, removing and re-installing the linkage to the brake pedal is very difficult. I ultimately decided to cheat and make this whole process very easy.......I removed the steering wheel column. Now since every thing was so accessible, I rebuilt the entire brake/clutch assembly with new nylon sleeve bearings. Also, the 70 has a tremendous heavy cast iron piece to mate the steering wheel column to the lower part of the windshield/birdcage. This heavy piece was replaced in the 82 cars with a stamped steel duplicate that weighs a whole lot less. Replaced this heavy piece also.

My suggestion is that this vacuum to hydrobeast conversion will be so much easier with the steering column removed. Removing the column is not that difficult.
 
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Pretty much what Gene said goes for my experience, too. It just stops, and with more confidence and control than before.
 
I ordered one from Hydra Tech a couple weeks ago. Decided I'd rather go with their kit than try to piece it together. Drove a city truck that has it, I'm sure I'll get used to it in this car.

I was planning on removing the seat anyway and am preparing myself for the under dash work by transcendental meditation and visualization exercises......Dropping the steering column sounds like a good idea too.
Thanks for the pump tip, I will keep that in mind.

This is going to happen over the winter while I have the engine out for a rebuild, and while that's happening I am going to replace my front hard brake lines. I know I have a kinked one (because I did it, years ago) and the car tends to swerve when I hit the brakes hard. The hydra boost idea was prompted by the brake lines, "while I'm at it."

I'm also contemplating a vacuum guage and perhaps a trans temp guage where the radio was and I need to do something with my wiper switch so I'll probably have the dash apart again too......

When it's up and running again next spring I'll give a review of what I think about it.
 
I've installed the hydro-beast in my 70. I haven't yet driven the car.

From what I've read for the hydroboost to operate properly, the return low pressure hydraulic line must have NO back pressure. GM sells a PS pump made for vehicles equipped with the hydroboost. The PS pump has TWO low pressure return lines...one for the Power Steering and the other for the hydroboost. The low pressure return line for the hydroboost was specifically chosen as to it's location....it's a less backpressure location than the power steering low pressure return. To locate the hydroboost return line into the Saginaw PS pump, a plexiglass model of the pump was built so that flow patterns could be seen to verify no backpressure. I can send you the PS pump part number. A complete new PS pump with the proper hydraulic lines can be bought for about $90 I think.. rockauto.com

Going to remove the factory vacuum canister assembly from the firewall are we???? Prepare yourself for a lot of fun. Of course you'll remove the driver's seat to try to get access. You'll need a long entension and a U joint drive to get at the nuts on the drivers side of the firewall. One nut is extremely difficult to remove. Also, removing and re-installing the linkage to the brake pedal is very difficult. I ultimately decided to cheat and make this whole process very easy.......I removed the steering wheel column. Now since every thing was so accessible, I rebuilt the entire brake/clutch assembly with new nylon sleeve bearings. Also, the 70 has a tremendous heavy cast iron piece to mate the steering wheel column to the lower part of the windshield/birdcage. This heavy piece was replaced in the 82 cars with a stamped steel duplicate that weighs a whole lot less. Replaced this heavy piece also.

My suggestion is that this vacuum to hydrobeast conversion will be so much easier with the steering column removed. Removing the column is not that difficult.

I get nightmares by just thinking about this.
 
I ordered one from Hydra Tech a couple weeks ago....... When it's up and running again next spring I'll give a review of what I think about it.

New to this forum... looking forward to that review. Considering the same myself, mostly to clean up the engine bay and have some more space to get my hands in on the big block
 
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