More hydroboost questions

[76zimmer]

I know I'll want hydroboost, so I've been trying to find some setups that I could relate to, and now I'm confused more about the hydroboost systems, and different setups people are using.
I know there are different threads/hose connections, and even hydroboost type pumps, but I couldn't find the break of whats what for the pump I have or need?.

First off what years/models hydroboost units fit the older 2nd gen. trucks? (77 body to be exact).

I have a serp setup for the BBC that is a GM performance parts kit. I'm pretty sure it is a P pump, but not a specific hydroboost unit.
Will that pump work for a hydroboost system?

what needs to be done for the pedal pushrod to h/b slave cylinder?

 

[76zimmer]

any ideas here guys?
Thanks

 

[mosesburb]

Your pump will work to feed the hydroboost system. It is an o-ring fitting unit, thus, I would recommend a 80 and up hydroboost unit from a C/K/R/V and a corresponding box to make the hoses all have the same fittings (i.e. o-ring hydroboost and an inverted flare steering box will make your life much more difficult than it needs to be). If you are buying lines you can get them for a mid/late eighties K/V application with a big block and you are done. The pumps are basically the same, but it is the reservoir that makes the biggest difference between hydroboost and non-hydroboost. Hydroboost reservoirs have two return lines and std pumps have one. I have heard of people using a "T" fitting into the single return line of a non-hydroboost pump for the hydroboost return, but I would prefer the second hose nipple myself. That being the case, you can use your pump and either get a different reservoir (AC Delco supplies reservoirs for less than the same part at the dealer), or if you are running a remote reservoir you can run the hydroboost return line to the remote reservoir. You can add a return line to your current reservoir by attaching a piece of 3/8" steel line to it. I have done this and highly recommend using silver solder as opposed to brazing. I have brazed them only to crack the thin sheetmetal of the reservoir wheras the silver solder requires less heat and gives a very solid joint when finished.

As far as the brake pedal attachment method goes, it should be the same as what you have with the vac booster. GM often had different brake pedals giving slightly more or less leverage than another, but I do not know if they did this on hydroboost or not. All you need to find is a K/V series truck with a hydroboost and grab the reservoir, booster and steering box and you're done, sort of.

 

[dremu]

I know I'll want hydroboost, so I've been trying to find some setups that I could relate to, and now I'm confused more about the hydroboost systems, and different setups people are using.
I know there are different threads/hose connections, and even hydroboost type pumps, but I couldn't find the break of whats what for the pump I have or need?.

First off what years/models hydroboost units fit the older 2nd gen. trucks? (77 body to be exact).

I have a serp setup for the BBC that is a GM performance parts kit. I'm pretty sure it is a P pump, but not a specific hydroboost unit.
Will that pump work for a hydroboost system?

what needs to be done for the pedal pushrod to h/b slave cylinder?

In my experience, the brake pedals are different for hydroboost than for vacuum -- specifically, the lever attachment point for the pushrod. Later pedal may have holes for both, I don't know. I had to change the pedal on my '74 to fit the (80's, O-ring style) hydroboost pushrod.

Most folks say that the pumps proper are the same, save that the hydro reservoirs have two return fittings.

You could fudge this with a tee fitting... see

http://www.slosh.com/ck5/tfitting1.jpg

and

http://www.slosh.com/ck5/tfitting2.jpg

Note that in the first one the two return lines essentially oppose each other which is bad hydraulic juju.

-- A

 

[76zimmer]

thanks guys, this gives me some answers I needed. I'm on the hunt.

 

[76zimmer]

OK, how bout some adapters to go from flare fitting to Oring design on my 79 2WD box?

 

[mosesburb]

Steering boxes are too cheap and easy to get to waste time and money jacking around with adapters. I do not know of an easy way to do it without custom made lines. O-ring to flare would be easy as you could use a line with an o-ring fitting on it and double flare the other end and use a union to the flare, but vise-versa is not easy.

If it were me, I'd get the right box--save time and money.

 

[COCHEV]

the first time i did this swap was in a 78 with an 80s hydroboost. i took the two ends i needed to a hydrolic shop and had lines made. i don't remember how much is was, but i'm sure it wasn't bad cause i was a poor bastard back then. i think now, i'm just a cheap bastard...anyways,

use the hydroboost pedal or move to the upper mounting hole if your pedal has it. the attached pic shows that. the one on the left is vac boost. but it has the hole above for hydro. the one on the right it hydro. not sure how they press that damn fitting in there, but didn't mess with it. just used a hydro pedal.

i also just used a reg power steering box this time around. put a tee in the return line and it works just fine...