Was it difficult to install? How did you connect the hy boost to the brake pedal? Mine doesn't have a clevis! :confused2:
It's probably been 5 years or so...time flies. My 70 had factory power brakes. I wanted to get rid of the vacuum canister to make room for valve covers on a BB and more spark plug access. Removing the factory vacuum canister was very difficult. It has to be done from inside the passenger compartment. Laying on your back with extensions and u-joints to get the top two nuts...I think the nut nearest the centerline is the hardest. You can't see what you're doing. It has to be by finger feel. This is a 6'2" 220 lb guy laying on his back with the driver's seat out. To mate the hydrobeast onto the car...wrestling to get the vacuum canister off had took the fight out of me. I removed the steering column...a surprisingly easy thing to do! Voila...everything now became sooooo much easier. My 70 was a close to 100,000 mile car, so at this juncture I redid completely the shaft with the brake and clutch pedals. Replaces all the nylon sleeves which act as bearing. Put in a new clutch pedal metal arm...Volunteer Vette.
I haven't driven my 70 with the hydrobeast in it yet. From reading other people's experiences, it appears the hydrobeast low/no pressure line must be able to dump into the PS pump reservoir with no back pressure. Apparently any tiny amount of back pressure on this line, will make the hydrobeast sensitive to lock up. (I'm repeating what I've read...I have no actual experience that tells me how true this statement is.) The hydrobeast was stock equipment on GM vans and also apparently a Cadillac sedan. Best I remember, posters who had driven stock GM vans and the Cadillac, reported that the braking sensitivity of their hydrobeasts was similar to a stock vacuum unit (at full vacuum). It was recommended that the low pressure hydrobeast retutn line NOT be joined to the low pressure return line from the PS hydraulic ram....instead braze a separate fluid return line into the Saginaw PS pump housing...aka the reservoir, or the "ham can." A poster suggested brazing the return port into the fluid fill tube for minimum return pressure...Getting to the punch line now...GM Saginaw engineers (Jim Shea, Mike Shea?) determined, with a clear plexiglass model of the PS pump reservoir (the ham can) where an optimal low/no/negative pressure? point was in the PS pump reservoir. The vans and the one Cadillac model sold with hydrobeasts had a PS pump reservoir with two return lines..one for the PS and one for the hydrobeast. I bought one of these PS pumps for my 70. It was only about $90 new from Rock Auto. It's in my garage and I have the part number. ...Heavens! will this story EVER end? This hydrobeast specific PS pump has a press on pulley. Bottom line, I need the older style keyed pulley. So, I have yet to pull the PS pump out of the stock reservoir and the PS pump out of the hydroboost reservoir and interchange them. It's pretty easy to do, I just haven't done it yet.
Mrvette alluded to some sensitivity with his hydrobeast and from his comments he's happy with it's performance. I'm assuming he doesn't have the hydrobeast specific Saginaw PS Pump reservoir can. I'm guessing, he has an adequately unrestricted return line. .............Anyhow, I've never driven my 70 hydrobeast equipped car, so I'm kinda dry lab'ing everything here.
Will this story EVER end, Part II. I think if you get the GM PS pump designed to be used with the hydrobeast, not only will it have a pressed on pulley, but it will have a metric high pressure output. I had a custom made high pressure line made for about $80...I didn't know that an English/metric adapter coupling made out of brass cost, from NAPA, $7.50. I don't want to use a pressed on PS pump pulley. I have March billet aluminum pulleys, and I'm afraid that if pressed on, they just break lose and spin.