BC Broncos rear disc bake caliper question

[1sicbronconut]

I've had a BC Broncos rear disc brake set up for years with the Eldorado E-brake set up. The set up is under my buggy now and I'm not going to use the E-brakes anymore any body know a application for the non E-brake calipers by chance, I've read it's the "Metric GM calipers" but that doesn't help much when I go to the parts store;D

 

[bigjhoov]

http://www.speedwaymotors.com/1978-Up-GM-Metric-Brake-Calipers-IMCA-Approved,4126.html

These stock replacement single piston Metric calipers were standard equipment on 1978-88 GM mid-size cars (Cutlass, Grand Prix, Regals, Monte Carlo, etc.).

 

[Apogee]

As stated above, the 78-88 GM G-body applications all used the D154 metric calipers, as did the 1982-1987 F-body (Camaro/Firebird), S10/Blazer/Jimmy, etc. There are some variations in the inlet port positions depending on the specific application, but they all used the same D154 pad spec and had the same 5.47" [139mm] pin spacing. FWIW, they also used larger pistons (2.50") than the rear parking brake calipers (2.03"), so they'll increase your rear brake bias.

An alternative aftermarket caliper would be the Wilwood D154 caliper which is offered in several different configurations with more appropriate piston areas.

 

[bronconut73]

As stated above, the 78-88 GM G-body applications all used the D154 metric calipers, as did the 1982-1987 F-body (Camaro/Firebird), S10/Blazer/Jimmy, etc. There are some variations in the inlet port positions depending on the specific application, but they all used the same D154 pad spec and had the same 5.47" [139mm] pin spacing. FWIW, they also used larger pistons (2.50") than the rear parking brake calipers (2.03"), so they'll increase your rear brake bias.

An alternative aftermarket caliper would be the Wilwood D154 caliper which is offered in several different configurations with more appropriate piston areas.

I used the S-10 calipers but had to grind on them a little to fit.
They had what almost looked like cooling fins at the bottom but they weren't.
The only reason I was willing to massage them was that they were only $12 bucks a piece at Auto Zone.
Absolutely excellent little calipers. Been running them for 10+ years.

 

[Apogee]

The only thing I don't really like about the OE D154 calipers is that they were GM's low-drag design, which basically equated to a piston seal design with a higher than normal piston retraction. In theory, this was supposed to reduce parasitic drag between the pads and rotors thereby increasing the overall fuel effficiency, and maybe they actually did. GM typically paired these calipers (starting in 1980 IIRC) with quick take-up master cylinders to help offset the additional volume requirements created by the low-drag calipers. The quick take-up MC's have a stepped bore and check function which essentially act as two master cylinders in one...the larger bore pushing a low of fluid at low pressures and then the smaller bore pushing less fluid but creating more pressure above a certain pressure set point. Most afermarket kits using these calipers make no mention of any special MC requirements, so if your pedal seems longer than it should be, now you know why.

 

[ntsqd]

I don't believe that all D154 calipers are low drag, and I did have a truck ('91) with low drag D52's (first thing that I changed on that truck). I agree that the low drag calipers suck. A former employer's AstroVan had them and HATED driving that thing! Bias the year/model given to the parts looker-upper toward the early years of the available range to steer clear of them if possible.

As a long ago former caliper designer I think that grinding on a caliper should be a felony.

 

[bronconut73]

I don't believe that all D154 calipers are low drag, and I did have a truck ('91) with low drag D52's (first thing that I changed on that truck). I agree that the low drag calipers suck. A former employer's AstroVan had them and HATED driving that thing! Bias the year/model given to the parts looker-upper toward the early years of the available range to steer clear of them if possible.

As a long ago former caliper designer I think that grinding on a caliper should be a felony.

I used '82 S-10 calipers. I hopefully got the good ones. Brakes are firm with a high pedal.

There was lots of meat left. Just knocked off some nubs that kept it from sitting in the bracket well.