Brake boosters -- I've seen that the 1992-1996 brake boosters are separately cataloged from the 1990-1991 and 1984-1989, anyone know the differences?
Thanks,
Dave

 

I know my 86 only has 1 fluid reservoir

 

Thanks, let me clarify...

There have been variations in Master Cylinders (with different ratios, different number of lines, different bore diameters, reservoirs).... and then there have been variations independent of that in brake boosters. I needed to figure this out for the boosters.

From what I understand, there are basically three types of OEM C4 boosters (non-ZR1):
1. 1984-1989
2. 1990-1991
3. 1992-1996

Not concerned about the plastic vs metal.

Data indicates that the OEM 1990-1996 variants had a 9.4" diaphragm and 0.65 sq inch area. No data for the earlier booster. Brake pedal levarage ratio changed from 3.5 to 4.0 in 1992 and the ECM tray was added just before that... so If someone's knowledgeable about the actual booster differences, I would appreciate the help.

 

I have rebuilt thousands of them over the past 3 decades, and did one just a couple weeks ago. They are made here in Australia.

The differences are mostly insignificant, and generally relate to the pushrod assembly on different Corvette versions, and even then it isn't much of a difference, i'd have to grab a few out to compare the rod to know exactly what the difference is. All parts between variants are interchangeable.

This series of booster was used on a number of Australian made cars in the mid to late 90s and early 2000s, and was also used on a number of Australian assembled cars in the 80s. The service kit is no longer available, and i now have to buy complete boosters and strip them to create rebuild kits. I can confirm the internal components that would be replaced in a rebuild are identical for all versions used in the C4 Corvette, the diaphragm is identical in every single one of them even when i buy one for a Ford Falcon or a Holden Commodore, the differences on those are again the pushrod and the Commodore has different studs due to a different mount on the firewall, both have a front cover with the vacuum check valve on the left instead of the right. the rear shell piece is physically identical on every single one, regardless of which car is is designated for.

The ZR-1 booster is also made by PBR in Australia and is not specific to the ZR-1, it is used in a few other cars too. I don't have a list of those though, never needed to rebuild any of those.

84 boosters are metal and not the same as 85-96.

What specifically did you want to know about or what is your goal?

 

That has nothing to do with the booster, that is only the master cylinder.

 

Thanks, you've more than answered my question... familiar with PBR and happy to see that on calipers, masters, boosters... but that probably makes me old :-)

The reasons for researching, are a little bit embarrassing for this group so I will skip... but certainly when ordering one there would be a lot of choices, and since my brake system is modified quite a bit, I needed to understand if there were different clearances for the ECM etc. and if there were slightly different sizes for the diaphragm to accommodate OEM changes over the years. Thanks again!

Dave

 

No need to feel embarrassed mate, it isn't a big deal

No difference in shells, and diaphragms are all identical.