Hydraulically assisted brake systems are nothing new; major manufacturers have used them in production vehicles for years. When it comes to the aftermarket, however, (lowriders in particular) the technology is not nearly as common…as a matter of fact, it may be completely unheard of to some of you readers.
Simply put, hydro-assist units like Classic Performance Products’ HydraStop work in conjunction with the vehicle’s power steering system, pulling/sharing high pressure from the steering pump. In contrast to vacuum boost, which is dependent on a number of variables, namely the size and configuration of the booster for its usable pressure, hydraulic pressure is considerably higher, providing more usable/consistent power assist to the calipers during normal operation. For instance, a standard 7-inch vacuum booster with a 1 and 1/8-inch bore master cylinder produces approximately 350 psi of available pressure — once that psi is used up during a hard stop, the remaining pressure required is supplied “manually”… in other words, the average 800 psi created by your foot. Using up hydraulically generated pressure isn’t as likely, if at all. Make sense?
As with vacuum systems, loss of pressure will cause loss of assist. However, in the unlikely event of a power steering pump failure (including broken belt), the HydraStop’s accumulator is designed to store hydraulic pressure, sufficient enough to provide approximately two to three assisted stops until reverting to manual power.
While the vacuum required to effectively power assist a vacuum-boosted system is low (18 inches minimum required), some older engines don’t produce enough vacuum to begin with, yet are capable of turning a power steering pump, making the HydraStop an ideal solution for attaining power-assisted brakes. Even with sufficient vacuum source, the HydraStop (in conjunction with a quality (preferably new) power steering gear and pump) offers a more consistent, all around better performing brake, hands down. And for that reason, we decided to have CPP’s Show Stopper bolt-in kit installed in our classic Impala. The system includes the aforementioned power-assist unit, CPP’s proprietary MCPV1 master cylinder with built-in proportioning valve, stainless and rubber hose, and all necessary fittings and hardware.
1. No more vacuuming: Classic Performance Products’ fully detailed Show Stopper HydraStop power-assist brake system.
2. Before installing CPP’s integral HydraStop, the master cylinder is removed from the hydraulic assist unit for two reasons: bench bleeding the cylinder and easing installation of the unit altogether.
3. Bench bleeding the master cylinder helps ensure air is removed from the cylinder’s bore passages; CPP provides convenient bleed kits to simplify the process.
4. On this Impala, the unit mounts to the firewall using the existing factory MC/vacuum booster holes.
5. The stock brake pedal pushrod hole is in perfect centerline alignment with the HydraStop booster; however, adjustments may need to be made (higher or lower) for other applications to attain the correct throw position.
6. With the master cylinder installed and brake lines re-attached, the entire brake system is then bled. Notice the “forced” method is being used (with a small syringe), as this works more efficiently and quicker than manually or even with a power vacuum system.
7. The Show Stopper kit comes with braided stainless high-pressure hose (standard rubber for return lines) as well as all necessary fittings.
8. The stainless lines are provided “cut to fit” (one fitting pre-installed). This is one of the more important steps of the procedure, cutting stainless and installing fittings, as they’re carrying the high-pressure fluid and require an absolutely tight, secure seal/fit.
9-10. First, the metric O-ring to AN pressure fittings are installed in the HydraStop unit as well as the power steering box.
11. The feed (pressure out) to the steering box is the port immediately behind the return (to reservoir) barbed fitting; the feed from the power steering pump (pressure in) is to the right, on the driver side of the unit, nearest to the accumulator.
12-13. The following steps may be the most crucial: cutting the braided stainless and installing high-pressure fittings. If you haven’t done this before, consult your local hydraulic shop or hose maker. Two preferable methods of cutting the hose are with a pneumatic cutoff wheel equipped with a thin blade and/or by using a sharp (undamaged) chisel and heavy hammer; both with the hose taped to help prevent fraying.
14. It’s important not to damage (flatten) the internal Teflon hose, as the fitting relies on that for a tight seal. The brass ferrule installs (taper facing inward) onto the Teflon; the screw-on fitting collar should be slipped on prior to cutting.
15. When installing the fitting assembly, always mark your hose “orientation” before completely tightening the fittings; using a vise may help keep things in line, as you can hold the hose itself rather than both halves of the fitting.
16. Included in the kit is an inline filter; use it! Any debris accumulated in the power steering system can and will damage the HydraStop unit. Install the filter in the return line to reservoir.
17. If using a Type II GM power steering pump, check to ensure your particular pulley can facilitate the 90-degree fitting on top of the O-ring adapter fitting.
18. It may be necessary to remove the power steering pump pulley to install the hose with the pump on the engine, as shown.
19-20. The high-pressure line was first test fit on the pump and orientation marked before the fitting was completely tightened down and reinstalled. Alignment is important here, as the hose needs to direct away from the pulley, but not into the engine block.
21. With the pump portion plumbed, the GM power steering reservoir was installed and connected to the system.
22. Finally, to complete the return system, the supplied T-fitting was installed inline between the steering box and brake booster.
23. Once our LS3 engine is wired and fired, we’ll properly finish off the HydraStop install by adding fluid to the system, perform the bleeding process, and getting everything ready to hit the road.