Vacuum or Hydraulic Brake Assist

[Michael79]

I have a problem with my vacuum brake booster which now needs replacing. I'm interested in the hydraulic brake assist system on offer from Hydratech but its an expensive option although it has several advantages in terms of size, power and overcoming the poor vacuum from my fairly radical cam.
Does anyone out there have any experience with the system?

 

[Twin_Turbo]

I have one, not trying to kill hydratech's business but if you're on a budget, go to the junkers and look for diesel vans and trucks, they're in there. Get one with a n2 reserve canister.

 

[Michael79]

Thanks for the tip TT, what is the performance like, was it difficult to fit, any problems after fitting?

 

[Twin_Turbo]

stopping power is much much better w/ a hydrobooster. It's not that difficult, only make sure you get a booster w/ an angled firewall mount plate, if you have a straight one you might have probs with the MC hitting the hood.

You may need to mod the rod, some are very long whilst others are short. The pattern on the HB is the same as on the vac booster. If you get one from a car that used both vac & hydroboosters in it's production run (gasoline > vac, diesel > hydro) then it's almost guaranteed it'll fit.

 

[WhalePirot]

The HydraTech package looks very well considered and made.

I plan to try a (cheap) 12vdc vacuum pump to boost the low vacuum delivered by my 406 before jumping to this expensive option. My web research points to outstanding, if touchy, braking capability with the hydrabooster.

I am told by another hydraboost vendor that the power steering pump really needs some modification for the conversion, to allow adequate fluid flow. The reserve pressure seems like a smart idea, in case the pump stops turning for any reason.

 

[Twin_Turbo]

You may want to grab a larger capacity pump indeed, so just grab one off a car w/ power steering and the hydrobooster. I have an aluminium KRC pump that will flow more than enough to power the steering and brake booster.

 

[MaineShark]

I haven't had a chance to road-test my system, yet, but the quality of the Hyrdatech unit was certainly top-notch, and Paul has been very helpful with my questions. As far as teh junkyard system... I might consider that, for anything other than brakes. Brakes, I don't count pennies on. I have a bit of engineering in my background, so I have to know why things are the way they are. That led me to ask Paul lots of questions, and I really did come away with the impression that he is very knowledgeable, and cares about his product. For example, he actually did his own testing to determine what was the best line to use for the hydraulic connections, rather than just taking the manufacturer's word for it. Not trying to sound like a commercial - just saying that I'd rather have that sort of professionalism behind the most important safety system in the car.

As far as the pump flow rate, I had the same concern. Paul's response was that anything later than early-70's should have the higher-flow pump, already installed. If not, the output fitting can be unscrewed (I believe it's a 1" hex - slide under your car and take a look), and the orifice drilled out slightly (to from 1/8" to 5/64", I believe). The extra 1/64" diameter increases the flow from around 2 GPM to around 3.5 GPM.

I don't believe it's really a concern with the fairly fluid-efficient power steering system that we have. I'm planning on converting over to a rack&pinion system at some point, and will make sure that my pump either has the 5/64" orifice, or drill it out, at that time.

Like I said, I haven't been able to road-test the system yet (pesky problem of not being able to drive the car without a cooling system... ), but Paul has said that nearly all the braking is done within the first inch or so of pedal travel, so it requires a lighter touch, to avoid locking the wheels all the time. If you're someone who feels the need to slam the brakes all the time, this might not be for you...

I also added a cooler to the system, so that added to my complexity a bit. If you want to do the same, and have any questions on it, ask away.

Joe

 

[Brutus]

I just finished installing one of Paul's rebuilt units to my RHD 77 and aside from minor issues due more to the steering configuration, I have nothing but praise for the system and Hydratech's product. The pedal feel now is simply light years ahead of what I've been used to and as stated in the instructions, I will be shortening the pedal throw to accommodate the new found braking power.