I did a DIY AstroVan HB conversion... the astro master cylinder is too long... and is binding or near binding with the PS reservoir cap..... I don't like it....
I would like to find a master cylinder that will work that is aluminum... not the big cast iron monster you see on some conversions.....
Any ideas?
I read PowerbrakeBob suggests a bore size of 1.125". The stock '85GN had a slightly smaller bore...1.0625 or something.... I wonder how critical that is.... IMHO you pick too big... the car will lock 'em up with only a minimal travel of the brake pedal.... too small.... the pedal will travel to far before the brakes lock up.....
To add even more confusion.... a lot of the master cylinders have two different bore sizes.... a smaller one for the rears (I guess) and a larger one for the fronts.... I don't think the HB master cylinders are like that however.....
After about 30 minutes searching online.... a 1995 Suburban 1/2 ton has a 1-1/8" bore... and has the 9/16 x 18 and the 1/2" x 20 line sizes....might have a winner..... if it is shorter than the AstroVan unit....
From the Napa Site....
Features & Benefits:100% OE Quality New Seals Are Installed On Every Unit. OE Performance And Reliability.
# of Line Ports:2
Brake Cylinder Bore Size:1.12500
Finish:Rust-preventative Finish.
Line Thread Size:1/2-20;9/16-18
I would like to find a master cylinder that will work that is aluminum... not the big cast iron monster you see on some conversions.....
Any ideas?
I read PowerbrakeBob suggests a bore size of 1.125". The stock '85GN had a slightly smaller bore...1.0625 or something.... I wonder how critical that is.... IMHO you pick too big... the car will lock 'em up with only a minimal travel of the brake pedal.... too small.... the pedal will travel to far before the brakes lock up.....
To add even more confusion.... a lot of the master cylinders have two different bore sizes.... a smaller one for the rears (I guess) and a larger one for the fronts.... I don't think the HB master cylinders are like that however.....
After about 30 minutes searching online.... a 1995 Suburban 1/2 ton has a 1-1/8" bore... and has the 9/16 x 18 and the 1/2" x 20 line sizes....might have a winner..... if it is shorter than the AstroVan unit....
From the Napa Site....
Features & Benefits:100% OE Quality New Seals Are Installed On Every Unit. OE Performance And Reliability.
# of Line Ports:2
Brake Cylinder Bore Size:1.12500
Finish:Rust-preventative Finish.
Line Thread Size:1/2-20;9/16-18
