Is there a certain or maximum bore size to use or look for when considering a master cylinder upgrade? Everything has been upgraded as far as the brake system accept for the master cylinder.
Good advice. Very few people seem to understand the relationship of bore size and how it affects the rest of the system. They end up with a firmer pedal feel but not realizing they actually have less pressure in the linesIt would be good to know the capacity or recommended master bore size of your calipers or wheel cylinders (if you have rear drums). Going above the recommended size would result in less required pedal travel, but more pedal effort. And you may need a pedal stop. And depending on your setup you may need a proportioning valve. If your front calipers aren't getting enough fluid pressure then you may have a rear brake bias bordering on "dangerous."
Good advice. Very few people seem to understand the relationship of bore size and how it affects the rest of the system. They end up with a firmer pedal feel but not realizing they actually have less pressure in the lines
Excellent information. Now what if I want to upgrade the rear drum wheel cylinders to the larger units from an '82-'86 S10 w/manual brakes or '95-'97 S-10 (same part #)?Here is my opinion on master cylinders and calipers.
I do not like the 1982-1988 step bore master cylinders. I believe these master cylinders give you a spongy pedal because of the internal transition from a larger volume bore to a smaller bore. These are meant to work with LOW drag calipers.
If you have a stock 1982-1988 G-Body, with the original, never been replaced calipers, they are LOW Drag or Quick Take Up calipers. The 1978-1981 "G-Body" calipers are NON low drag or "normal" calipers.
That being said, these metric, D154 calipers were used from 1978-2004ish. Below are the vehicles that used the metric, D154 calipers.
1978-1981 "G-Body"
*Normal, NON low drag front calipers.
*24mm (roughly 15/16") strait bore master cylinder.
*Outlet ports on DS fender side of master cylinder.
*1/2-20 and 9/16-20 IF outlets
1982-1988 G-Body
*LOW Drag/Quick Take UP front caliper.
*24mm/1.25" Step bore master cylinder.
*Angled Reservoir.
*Outlet ports on DS fender side of master cylinder.
*1/2-20 and 9/16-20 IF outlets
1982-1997 S-10
*LOW Drag/Quick Take UP calipers.
*24mm/1.25" Step bore master cylinder.
*Flat Reservoir.
*Outlet ports on DS Fender side of master cylinder.
*1/2-20 and 9/16-20 IF outlets.
1982-1992 F-Body
*LOW Drag/Quick Take UP calipers.
*24mm/1.25" Step bore master cylinder.
*Angled Reservoir.
*Outlet ports on engine side of master cylinder.
*Metric bubble flare outlets.
1998-2004ish S-10 - Normal, NON low drag caliper.
*1.0" strait bore master cylinder.
*Outlet ports on engine side of master cylinder for left hand drive models.
*Both 1/2-20 IF outlets on Left Hand Drive Models.
**Outlet port on DS fender side of master cylinder on RIGHT hand drive models.
**1/2-20 and 9/16-18 IF outlets
ALL YEAR driver side CALIPERS WILL HAVE THE SAME PART NUMBERS regardless if they came with LOW drag calipers or NORMAL calipers.
ALL YEAR passenger side CALIPERS WILL HAVE THE SAME PART NUMBERS regardless if they came with LOW drag calipers or NORMAL calipers.
I believe, all calipers "should be" rebuilt to normal standards as they will be able to work with a strait bore master cylinder or a step bore master cylinder.
If a caliper was rebuilt to the LOW drag standards, you will get a LOW spongy pedal if using a strait bore master cylinder, so I suspect all calipers are rebuilt to normal, NON low drag standards.
Good Replacement master cylinders for most stock type disc/drum or stock type disc/disc setups.
Replace your factory stock, never been replaced calipers to use these master cylinders.
1998-2004ish S-10 Right Hand Drive, master cylinder
*1.0" bore
*1/2-20 and 9/16-18 IF outlets like all G-Bodies
2005 Chevrlet SSR
1.0" Bore
1/2-20 outlets. Use Adapter (AGS PN BLF-26C) for the line going to the rear brakes.
If using a 1990 B-Body vacuum booster, step up to a 1-1/8" Bore master cylinder.
2000 Chevrolet Express Van 1500 Master Cylinder with a 1996 Chevrolet Caprice Reservoir (sold separately)
The Express Van master cylinder has the correct 1/2-20 and 9/16-18 IF fitting for stock G-body Brake Lines
The 1996 Chevrolet Caprice Reservoir is angled to work with the angle of the G-Body Firewall.
Let me know if you have questions.
Dave
In my opinion, the wheel cylinders size is not that important. I believe the stock drum brakes should have plenty of stopping ability. I would add the wheel cylinder brackets to "lock" the wheel cylinder to the backing plate. With this type of wheel cylinder, they tend to move a little front to back when braking without the bracket to lock it, which should reduce your braking performance slightly.Excellent information. Now what if I want to upgrade the rear drum wheel cylinders to the larger units from an '82-'86 S10 w/manual brakes or '95-'97 S-10 (same part #)?
These cylinders have a 1/8" larger bore as well as bolt-in retainers. Should they be paired with a 1990 Caprice brake booster and large bore master cylinder (without switch) or would a small bore be better? Proportioning valve changes would be required, of course.
And just for fun, what if I upgraded to 1LE ('88-'92 Camaro) or LS1 ('98-'02) brakes for the front? Can I do the either of those in conjunction with the S10 cylinders out back? I understand swapping to rear discs is the obvious answer but these upgrades tend to happen in stages.
My Cutlass needs the booster and master replaced soon so I'd like to get this all planned out. Thanks guys.
GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.