Manual Brake Conversion with Pictures

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
226
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Houston, TX
Re: Manual Brake Conversion on a 1980 El Camino

I have purchased 3 different metric calipers for comparison:

**CCP big bore 2.75" bore (2.565" piston diameter) metric cast iron caliper – WEIGHT 6 lbs 11.2 oz bare with slider bushings installed
**US Brake standard bore 2.5" bore (2.376" piston diamter) metric cast iron caliper- WEIGHT 6 lbs 4.7 oz bare with slider busings installed
**Wilwood small bore 2.0" bore (1.981" piston diameter) metric cast iron caliper - WEIGHT 4 lbs 1.7 oz bare with NO SLIDER BUSHINGS INSTALLED.

A while back I purchased NEW the $59.95 each, big bore calipers from speedwaymotors.com. There was some manufacturing issues or problems with these calipers and they sent me replacement calipers. The replacement calipers are NEW CCP big bore metric calipers. PN CP412526. Online, these are the same price of $59.95 each from classicperform.com. They look exactly the same except for the paint on the calipers. The originals where painted/powder coated silver. These are painted/powder coated black. The caliper housing, compared the standard bore US Brake 2.5” calipers and 2.0" Wilwood calipers, are a different casting. The piston looks to be stainless steel and comes with a dust boot installed. The piston diameter is 2.565" in diameter. These calipers came loaded with pads, slider bolts/pins, and hose fittings. You should be able to bolt these to your car, bleed the brakes, and drive. The piston cylinder side of the caliper is roughly the same size as the as the standard 2.5” bore caliper.

I recently purchased NEW, US Brake/Afco branded 2.5” standard bore metric calipers. They are $45 to $50 each online. The casting is not painted or powder coated. They come in a right PN 7241-9003 and a left caliper PN 7241-9004. They cannot be interchanged from side to side. The piston looks to be a cast steel/iron, unlike the CCP 2.75” and Wilwood 2.0” bore calipers. They are also 2.376" in diameter which matches stock advertised piston/bore sizes. The casting looks to be a stock casting and comes with a dust boot installed. It has all the markings of a stock calipers. This caliper came unloaded with no pads, slider bolts/pins, and hose fittings. It does come with the bleeder screws and bushing inserts for the slider bolts/pins. You will have to reuse your slider pins from your stock calipers and hose fittings. You will need to purchase new pads or reuse the ones you have on your car.

I also recently purchased NEW, Wilwood 2.0” small bore metric calipers. PN 120-9333. The price is round $80 each online. It is also a different casting from the other two. Visually the casting looks better and it looks to come with a stainless steel piston that is 1.981" in diameter. The casting comes bare with no paint or powder coating and they can be interchanged from the right and left hand side of the car. The piston cylinder portion of the caliper is physically smaller than the other two because of the reduced size of the piston. The piston bore and stainless steel piston look to have a better, tighter fit. The clearance is so tight there is no dust boot installed around the piston like the 2.75” and 2.5” bore caliper above. These calipers only come with a bleeder screw. It does not come with any other hardware. You will have to supply the slider bolts/pins, slider bolt/pin bushing inserts (I need to make sure this is possible), brake pads, and hydraulic hose fittings. All hardware should be able to transfer over from your original caliper. Please refer to this web page for more details. http://www.wilwood.com/PDF/Flyers/fl176.pdf

Out of the three calipers above, I was most impressed with the Wilwood calipers. These calipers have a very clean casting that weigh at least 2 lbs less than the other two calipers. The Wilwood website list a 2.75” bore version also that weighs just 5 more ounces than the Wilwood 2.0” bore versions (4lb 6.4oz v 4lb 1.6oz). These Wilwood iron calipers weigh roughly 1lb more than the Willwood comparable aluminum metric caliper with the 2.38” bore (4lb 6.4oz v 4lb 1.6oz v 3lb 6.4oz). I also suspect that the piston to bore clearances are just as tight as their 2.0" verson which will give the 2.75" version of the Wilwood caliper a larger piston that that of the CCP version. It theory this gives more clamping force.
 

malibudave1978

Amateur Racer
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Jun 8, 2004
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Houston, TX
Re: Manual Brake Conversion - Step by Step Install

Pics of the CCP 2.75" Big Bore Metric Caliper
CCPSideView.jpg

CCPPistonView.jpg

CCPTopView.jpg

CCPBottomView.jpg

CCPPistonSideView.jpg

CCPwithPadInstalledSideView.jpg
 

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
226
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Houston, TX
I purchased my second new master cylinder from rockauto.com a while back and just now had time to install it. The master cylinder is a Centric brand PN# 130.62005. It is a manual brake master cylinder for a g-body with a 7/8" bore. I installed it and bleed the brakes from back to front and got a good, firm pedal. I left the speedway motors recalled calipers installed, for now, to see how the system all worked together. I noticed, while I was under the car bleeding the brakes, I saw a lot of caliper defection as my dad pumped the brake pedal when the bleeder screws where closed.

How did it do? For the setup I have, it did very well. I could not lock up the front brakes, but the braking felt more confident than when I had the stock, 24mm bore power master cylinder . I felt, if I was driving this on the street a lot, I wouldn't have to anticipate my braking. I felt I could stop where I wanted to when I wanted to under normal street driving. As expected, the pedal stroke is longer than a power brake pedal.

What would I do different? I would find a better front caliper. I think I will try the Wilwood single piston, 2.75" bore, metric caliper. From my experience with the inspection of 2" bore, Wilwood, single piston, metric calipers, I think the 2.75" big bore Wilwood will have a larger piston that the CCP/Speedway Motors 2.75" big bore caliper. I just worry that any 7/8" bore master cylinder may not have the volume of brake fluid needed to make these work.
 

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
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Houston, TX
Things I learned from this process.

*New master cylinders are hit or miss in functionality. My first new one I bought did not work, but it was a clearance item from rockauto.com. I ended up spending another $80 plus shipping for the Centric brand one that actually worked.
*The larger the caliper piston is the better the clamping force.
*Caliper deflection affects brake performance more than I thought.
*The smaller the bore of the master cylinder is the better the pressure to the caliper.
*But if the bore of the master cylinder is to small, it may not have enough fluid to fully compress the caliper piston.
*The diameter of the brake rotor also affects the performace of the brakes not only because of rotor area and heat dissipaton, but also a larger diameter rotor gives the brakes greater leverage. Just think of using a 6" long breaker bar instead of a 5.25" braker bar to get a bolt loose. A longer bar will have a easier time getting the bolt loose. A 10.5" rotor has a 5.25" (half the rotor diameter) of "leverage". A 12" rotor has 6" of "leverage". Larger is better.
*They make brake pad designed for drag racers. They work better when cold and are for vehicles that do not use their brakes on a daily basis.
*Wilwood makes nice metric calipers.
 

Wile E

Dragway Regular
Aug 11, 2003
1,075
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Central WISC
Hey Dave, Thanks for the follow up. Looks like you've done lots of leg work sorting out the details. I finally got my US Brake/AFCO 2.5" calipers bolted up with the Bendix Titanium II pads. Picked up a set of stainless hoses and am in the process of installing my new pre-bent lines. I stayed with the standard size wheel cylinders and finally found a set of servicable aluminum drums. Won't have it on the road until next year, but with the info you've supplied, I have a good idea what to expect.
 

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
226
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Houston, TX
Wile E said:
Hey Dave, Thanks for the follow up. Looks like you've done lots of leg work sorting out the details. I finally got my US Brake/AFCO 2.5" calipers bolted up with the Bendix Titanium II pads. Picked up a set of stainless hoses and am in the process of installing my new pre-bent lines. I stayed with the standard size wheel cylinders and finally found a set of servicable aluminum drums. Won't have it on the road until next year, but with the info you've supplied, I have a good idea what to expect.

Let me know how you setup turns out. I would like to know if you see noticable deflection in your calipers once everything is installed. I did not set up the US Brake/AFCO 2.5" calipers I bought. I was so impressed with how the Wilwood's looked and the tight tolerences of the piston to bore, I want to try there big bore version to see if a 7/8" bore master can handle the volume and to see if there is any noticable decrease in caliper deflection. If there is an decrease in deflection in this caliper, I suspect there will be a substantial increase in the manaul brakes performance and well worth the $90 price tag each.
 

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
226
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Houston, TX
Just recieved my Wilwood 2.75" big bore calipers in today. These are very nice calipers, just like the Wilwood 2 inch metric calipers. The piston diameter measures 2.704 inches. On the underside of the caliper, there are ridges that bridge the piston side (inside) of the caliper to the wheel side (outside) of the caliper. These ridges are not present on any of the other calipers. These ridges should cut down of caliper deflection. The weight of each of the 2.75" calipers is 4 lbs 8.6 ounces with out the bleeder screw. I hope the 7/8" bore g-body manual brake master cylinder can handle the increase in volume these calipers may require.

Wilwood275.jpg

Wilwood275SideView.jpg

Wilwood275TopView.jpg

Wilwood275BottomView.jpg

Wilwood275PistonView.jpg
 

malibudave1978

Amateur Racer
Thread starter
Jun 8, 2004
226
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Houston, TX
Caliper Specs

Caliper............................Part Number........Advertised Bore Size.......Actual Piston Size.....Weight
Wilwood 2" Bore Caliper........PN 120-9333...................2.00"..........................1.981"................4lb 1.6oz
US Brake / AFCO Caliper.......PN 7241-9004..................2.50"..........................2.376"................6lb 4.7oz
CCP Big Bore Caliper............PN CP412526...................2.75"...........................2.565"................6lb 11.2oz
Wilwood 2.75" Bore Caliper....PN 120-8926...................2.75"...........................2.704"................4lb 8.6oz
 

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