So I converted mine over Christmas. Here are a few pointers you need to consider. Mine is 1999 Tahoe 4 dr.
Pedal
- you can use the stock one but you need to swap out the backing plate on the hyrdroboost with one that is centered (the one that comes with the hyrdroboost is offset to the bottom) There is a guy on ebay who sells them for cheap ($25) on ebay for an astrovan conversion, it is the same plate here it is
http://www.ebay.com/itm/300797723373?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
Steering Solonoid
- you don't need to use the variable steering sensor on the back of the pump (if you change to a hydroboost pump like I did) simply screw the pressure line directly into the back of the pump, you might need to "massage" the lines a bit to get it to route nicely, mine has a few of the stoc bends relieved so it clears the exhaust manifolds nicely, I didn't want my exhaust to heat up the fluid on the way to booster.
Brake switch retainer and pushrod
- You will need a new brake switch retainer as it's basically impossible to take the stock one off without destroying it. 1999 is different than the other years I think, you can get the retainers at advanced autoparts it is made by dorman I think it is like 5 bucks.
Master cylinder
- You need to match your master cyclinder to the hydroboost unit. Depending on the year and model the bore diameter of the hydroboost and the diameter of the protrusion on the master are different sizes. I ended up haveing to buy a new master cylinder from a C3500 1998 to match my hydroboost unit. Not a big deal but keep this in mind.
Hydroboost Pushrod, Retainer and Spring
- Finally, if you buy all new stuff like I did and you didn't get this stuff from the junk yard then you will find out that your stock pushrod (the rod that goes between the booster and the master) is too short and missing some parts. YOU MUST HAVE THE PUSHROD, SPRING and RETAINER assembly from a hydroboosted truck. Now I was lucky and hit the junkyard and pulled one and made it out for $5 bucks after some grumbling from the owner about it being part of the booster, some others might not be so lucky. Best advice is to plan on buying an old junk yard hydroboost with the spring, retainer and pushrod and swapping it out for a new one at the local autoparts store. Make sure you take out the old retainer and pushrod assembly before you do this because the reman units don't come with it!
Fluid
- Power Steering Cooler: my truck didn't have one and I didn't put one it. I did use lucas synthetic fluid and completely swapped out all the fluid when doing this (new pump, hydroboost and lines made this easy, I'm sure not much was left in the steering gear) I haven't noticed any issues with hot fluid but then again it is winter here in RI so I'll see how it is in the summer and may end up adding one.
Hydroboost to pedal pushrod
- Brake pedal booster pushrod: was fine I didn't need to modify this like others have said they had to, all you have to do is swap the booster backing plate to center it and it matches up in line with the stock pedal.
Impressions: Huge difference in brake feel, clamping force and stopping power! I heard this was a worth while upgrade but I never thought it would be this good. I Can haul this truck down from 60 mph and lock up the tires if I feel like it without much effort. And I have stock brakes, rubber lines and autozone duralast brake pads and shoes.
Again I did this on a 1999 Chevrolet Tahoe 4 Dr and everything I used was from a 1998 C3500 pickup with hydroboost!
Ken
