Made some progress this week on the truck, however small, its probably worth updating.. I decided it was time to tackle the brakes and get progress going on them...

So far these are the big parts I have.. I havent had a chance yet to address the flexible fluid lines since I am going to wait for the PS Pump from the corvette to be 'in hand' to assure proper length & fittings..


Keep in mind that I cant settle for any thing not being completely custom (so it seems) so the master cylinder is causing some additional expense on my setup. I wanted to go with LS1 Fbody car master cylinder as I figuired it would be better matched to the LS1 brakes on all 4 corners. (Piston diameters, rod stroke etc).. If you were going with a standard Astro or SyTy master cylinder (prolly same parts) it would be ALOT easier to do this and alot less fabrication involved.

The parts shown on the lower LH corner of the picture are parts that go INSIDE between the booster and master cylinder. These parts are NO LONGER AVAILABLE FROM GM for the '94 Astro setup. I managed to get them from a '00 2500 HD Parts catalog and thats what you see here. They fit inside the booster just fine, but the 'PISTON' is too short and is better illustrated here :




I'd strongly recommend that IF you go this route you check the overall length of your piston when going with an alternative master cylinder like I did... DONT TAKE MY WORD for the dimensional length on your setup.. Yes its tedious to check, but will provide the best results in the end.

I chose to clock the hydroboost booster UPSIDE DOWN so the fluid lines all run in and out of the bottom (so I didnt have to see them and to help with routing you can see the orientation here as well as the gap that was left over from the different plate sizing between the two boosters:



Since the LS1 master cylinder completely changes the output side of the fluid lines its going to require all custom lines be made. I figuired since the truck was 12years old, the stock lines were looking a little shabby, that I would just go ahead and replace them so I purchased a flaring tool and will be running AN fittings where I can. Here's the flaring tool :



Earls wanted $75+ for the same tool, that one was $42/shipped from Summit.





Standard Automotive brake fittings are 45* Double Flared, this setup is a single flare setup and its a 37* for all AN fittings, keep that in mind when doing brakes, you DONT want to mix and match those fittings/flares, at the least you will have leaks, worst case failure.

The only remaining item that needs to be addressed is the brake rod length where it attaches to the pedal. Its probably best to just post another picture here :



In the above picture "X" dimension is different between the Astro booster and the SyTy vaccuum booster. Some people prefer to 'cut and paste' with a welder these two rods.. Errrr. I'm sure it works, but I'm sorta nervous about doing that with a brake system part...

Both the of the items here are going to also be addressed in addition to the previously mentioned FILLER plate by Eric @ www.turbotime.us which will make the NAPA parts a straight bolt in setup. There will be parts coming very soon if you want to wait for them. Right now we just need to get the dimensions finalized and built.



Would I recommend following my build on this ?? (stupid question to ask a guy shoving an all aluminum v8 in the place of the wimpy 4.3L dont ya think ?)



Depends, if you want an all out matched setup and are running discs all the way around, then yes. (remember I am running LS1Fbody car discs all the way around, if you are still running stock brakes, stay with stock master cylinder.) and I just didnt like the idea of running a mismatched master cylinder. I am unsure of the effects, or if there is even a HUGE difference between the two master cylinders (may in fact be very close, who knows ?). I havent talked to anyone with this setup that runs discs all the way around and inquired about pedal feel or performance yet. I figuired it wasnt that much more of a headache to get it done correctly since I was this far into it anyhow. I guarantee you it can be done for cheaper/easier than I have done.. So far with the above parts, I am upto about $470 (flare tool is at your discretion, since it has other uses later on, I didnt include it) and these are all REMANUFACTURER or NEW parts with NO CORES available to offset the core charges. These nuymbers would be significantly LESS using junkyard parts or a combination of them. I also have to factor in the high pressure lines that I have NOT purchased yet, if someone is interested in purchasing them get in touch with me PRIVATELY and I can see if I can get Earls to make up more than one set (of course your ends will require accomodation to SYTY hose ends @ PS Pump).





Anyhow, I hope this information helps and of course, YMMV etc etc