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Manual Brake Conversion - G-BODY

59K views 43 replies 4 participants last post by  malibudave 
#1 ·
I just finished up upgrading the brakes on my father’s 1980 El Camino. This is a daily driver that I am testing several different master cylinders for a manual brake conversion swap. His brakes worked good before exchanging out all the parts, but I wanted to take out most of the variables when testing master cylinders. First and foremost, I wanted to make sure this 1980 El Camino did not have quick take up front brake calipers. In my research, quick take up calipers will make it difficult do get good pressure to the caliper when using manual brakes.

Here is the rundown of the parts I used:
• Speedway Motors Big Bore Metric Calipers - PN# 91031040 $59.99 each
• Bendix Titanium metallic front brake pads (FF Rated) - PN# MKD154 $38.22
• Turned the stock rotors $30 Local Auto Parts Store $15 each
• Edelbrock/Russel Stainless Steel Braided Flex Lines PN# 692100 $54.80
• Wagner 7/8” Wheel Cylinders from an manual brake S10 PN# F110261 $13 each
• Wagner Thermo Quiet Rear Shoes (EE Rated) - PAB514R from O’Reilly’s Auto $32.99

The Speedway Motors big bore metric calipers (2.75” bore v 2.38” bore standard) came with brake pads, but the pads did not have a rating on them. I DID NOT want to use a brake pad that would need a lot of heat to be effective. The weight difference between the two calipers is less than ½ of a pound. This is a daily driver and not an autocross car, so I chose the Bendix Titanium pads because my research and reviews showed them to have good cold clamping friction. Based on the EE rating, the rear shoes should also have good cold stopping abilities. Look on the pads or shoes when you buy them to make sure they have a rating on them. The higher up the alphabet you go the hotter the pads will have to be to work effectively. Pads or shoes with no rating on them should be avoided.

It was surprising to me to find a 24mm strait bore aluminum master cylinder on this 1980 El Camino. I didn’t know they made aluminum ones with a strait bore for g-bodies. I had always been under the impression, because it was aluminum, that this was a step bore master for quick take up calipers. I do know for a fact that any NEW replacement master cylinders for g-bodies will for than likely be cast iron. So if you want aluminum master cylinder for power or manual brakes that bolt up to your brake lines, a rebuilt master cylinder may be your only option.

I changed out the 30 year old rubber brake lines with the braided stainless. The front lines were a little longer than the originals, but I routed them so they were not touching any suspension pieces. The rear was a little more difficult to replace because the clip that holds the rubber line to the frame was difficult to get at. The new braided rear line was fairly easy to install also.

The hardest part to the entire swap was installing the rear wheel cylinders. Getting the clip off was not too bad, but getting the clip back on was a pain. I did it with two c-clamp, and open ended wrench, and the lid off of an old battery terminal cleaner (don’t ask for these details because I do not recommend doing it this way. G-H-E-T-T-O).

After the system install, bleeding the fluids, and bedding in the pads and shoes I took it out for a spin to test the brakes with the same master cylinder and vacuum booster from the original test with the original brakes. Even though I was able to easily lock up all four wheels, it seems to have a little more pedal travel before you could feel the brakes start to grab. I believe this has to do with the increased piston area in the front calipers and rear wheel cylinders while using the strait bore 24mm master cylinder. The 24mm master cylinder will have more pedal travel to fill the extra volume of fluid required by the calipers and wheel cylinders.

If keeping the vacuum booster, it might be best to step up to the step bore master cylinders that are used on the 1981 and up g-bodies. The primary bore is still 24mm, but it also has a larger step bore of 36mm that will increase the volume of fluid to the larger calipers and wheel cylinders.
 
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#27 ·
I do have a long pedal travel, but the brake "feel" starts about a fourth of the way down and full lock up, of the rear wheels, happens about 3/4th, or a little more, of the way down. I may be at the very limit of this 24mn bore master cylinder.

Though the 24mm bore MC is just a tad larger than the 15/16" bore. It might be just enough to run out of fluid.

Let me know how the 1" bore MC works with your setup.
 
#28 ·
Well, so much for the C3 Corvette master, after "oblonging" the holes so it would fit my stud spacing, it wouldn't clear the valve cover. Had to order a 1970 F-100 master that more resembles my tall, upright Granada master but in 1" bore. Maybe by mid-week...

Russ
 
#29 ·
Just to post back results, they were not good. The 1" bore master was still out of fluid at full stroke (pedal to the floor), even though a Wilwood tech assured me that 1" would supply plenty. In frustration, I swapped back to the original calipers, but did a full bleed after doing only one side. I had a pedal, but close to the floor. After swapping and bleeding both sides, I again had a good pedal. After all this d!cking around, the net change was from a 15/16" master to a 1" master, a lighter wallet, and a shelf full of wasted parts. I have not driven it yet, but I'm pretty sure the brakes will s%ck even worse than before...

Russ
 
#30 ·
Sorry to hear that. I have spent a B-load of money also to get to the point I am at. There is not reason that you should have gotten zero pressure when using a 1” bore master cylinder when I am getting pressure with a 24mm bore master cylinder using a 2.75” bore Wilwood calipers.

Things to try if you haven’t already:
1. How was the F100 brake lines mounted? Back brakes on the front port and Front Brakes on the back port (nearest to the firewall). How are yours usually mounted on the Maverick? I would think that you will need to match the brakes lines to what the f100 had, if the Maverick was not set up like the F100.
2. If you didn’t bench bleed the master cylinder, take it off the firewall and bleed it on the bench to make sure you get a full piston stroke.
3. Make sure your bleeder screw, on the front calipers, is pointing strait up when mounted on the spindle to make sure all the air gets out. If not, remove from spindle, C-clamp the piston in the open position, clock the bleeder screw strait up, and then bleed that caliper.
4. Make sure you’re your brake pedal is adjusted as far back toward the drivers seat as possible. Unscrew the brake light switch as far as you can with out it falling out easily, and then adjust the brake pedal pushrod out toward the piston of the master cylinder.
5. Measure the piston stoke at the pushrod attachment point. I should have 7/8” to 1” of travel.
6. Make sure your brake pedal pushrod is just barely touching the back of the piston in the master cylinder. DO NOT PRELOAD the Master Cylinder piston.
7. The brake pedal pushrod should be inline with the master cylinders piston’s center line. If not inline, you will not the same pedal stroke and also wear out the master cylinder quicker.

My sister had a manual brake Maverick from the factory (25, or so, years ago). I cannot remember if it was front disc brakes or the year (I think 1976). But it had a very high pedal. I cannot remember how it stopped, but I know when the pedal released, it made a thud sound when returning to the depressed position.

Let me know what you find out.
 
#31 ·
Sorry to hear that. I have spent a B-load of money also to get to the point I am at. There is not reason that you should have gotten zero pressure when using a 1” bore master cylinder when I am getting pressure with a 24mm bore master cylinder using a 2.75” bore Wilwood calipers.

Things to try if you haven’t already:
1. How was the F100 brake lines mounted? Back brakes on the front port and Front Brakes on the back port (nearest to the firewall). How are yours usually mounted on the Maverick? I would think that you will need to match the brakes lines to what the f100 had, if the Maverick was not set up like the F100.

See pic below, this is the Grenada master but the F-100 is nearly identical. You can see the TEE to the front circuit under the blue 2# resid while the red 10# resid feeds the rear circuit.

2. If you didn’t bench bleed the master cylinder, take it off the firewall and bleed it on the bench to make sure you get a full piston stroke.

I always do this.

3. Make sure your bleeder screw, on the front calipers, is pointing strait up when mounted on the spindle to make sure all the air gets out. If not, remove from spindle, C-clamp the piston in the open position, clock the bleeder screw strait up, and then bleed that caliper.

With the Wilwoods, I had to do this. I used a 1" thick hardwood block in place of the rotor.

4. Make sure you’re your brake pedal is adjusted as far back toward the drivers seat as possible. Unscrew the brake light switch as far as you can with out it falling out easily, and then adjust the brake pedal pushrod out toward the piston of the master cylinder.

I made my pushrod adjustable, and the pedal is at the stock height.

5. Measure the piston stoke at the pushrod attachment point. I should have 7/8” to 1” of travel.

Hmmm, this I will take a look at. I can adjust it some, but really don't want my pedal a foot off the floor!

6. Make sure your brake pedal pushrod is just barely touching the back of the piston in the master cylinder. DO NOT PRELOAD the Master Cylinder piston.

The pushrod is clipped into a groove in the piston so it cannot come out. On the other end, the pedal has no stop so it can float freely.

7. The brake pedal pushrod should be inline with the master cylinders piston’s center line. If not inline, you will not the same pedal stroke and also wear out the master cylinder quicker.

Everything is comparable to stock as far as alignment goes.

My sister had a manual brake Maverick from the factory (25, or so, years ago). I cannot remember if it was front disc brakes or the year (I think 1976). But it had a very high pedal. I cannot remember how it stopped, but I know when the pedal released, it made a thud sound when returning to the depressed position.

Let me know what you find out.
 
#32 ·
Dave,

You say this works, Wilwood says it works... It doesn't work on my car. This is making me think there's a problem with the rear circuit. Even though I have had as much as 30 PSI on my pressure bleeder, the rear wheels would still turn by hand. I get good flow from both rear bleeders and these were new, complete drum kits from Ford. Maybe they were built wrong? I didn't spend any time looking at them, just slapped them on. Would defective rears give me an extended pedal stroke? Now I'm wondering if I should remove the drums and see what's happening on a pedal press?

Russ
 
#35 ·
OMG!

You'll be happy to know the problem has been solved! There were (at least) two issues at work here:

1) After removing the rear drums (which I had so "carefully" adjusted) I found the PASS side to be spot on while the DR side had at least 3/8" clearance between the shoes and drum. This was causing a lot more master cylinder "stroke" to be absorbed by the rear circuit = increased pedal travel.

2) The bleeder screws were not at the highest point on the big-bore calipers, so I had them off the spindles and was using a 1" block of oak to simulate the rotor while bleeding them. What I wasn't seeing was that the oak block was actually deforming under the pressure. This time, after removing the air, I replaced the calipers on the spindles and finally had a good pedal. The car drives and stops better than before, so all is GREAT!

Russ
 
#36 ·
Glad to hear that you're stopping well again.

I have seen cases where, during the adjustment of the drums, the entire brake shoe assembly gets pushed to one side. This will give a "false" sensation of the shoes dragging slightly, making it seem that the shoes are adjusted w/a light brush w/the drum. But once the brakes are applied the shoes center themselves, and there's no dragging, or if there is still some drag, the shoes are still not out far enough.

I've gotten in the habit of taking the adjustment down far enough that the brakes are almost locked, then loosening them to the lightest drag setting.
 
#37 ·
Here is a list of strait bore master cylinders that will bolt up to a G-body’s angled firewall when using a flat, manual brake adapter plate. This is a list from smallest to largest.

21mm (0.826”) bore 1993 Dodge Shadow master cylinder (other years and models may work)
• Requires adapters to mate master cylinder outlet to stock lines. The adapter Part number is MC-SF at Disc Brake, Steering and Suspension Products for classic Chevy and Ford cars and trucks.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Hard to find.
• Light in weight.
• Advertised as 21mm, but may be delivered in 7/8” or 24mm bores. Measure bore size before you buy. Rebuilt/Used ones will have a “1” cast into the front of the aluminium body under the reservoir.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.

7/8” (0.875”) bore 1978-1980 GM G-body manual brake master cylinders.
• Can buy new or used. Rebuilt are fairly cheap. New are fairly expensive.
• Reservoir too small for rear disc brakes. The reservoir from 1979 Buick Riviera with four wheel disc brakes can be retrofitted to this master cylinder.
• Advertised as manual brake units, but may be delivered as a 24mm, vacuum power boosted unit. Measure bore size before you buy.
• Bolt in.
• Cast iron body – new, used, or rebuilt. (no aluminium)

7/8” (0.875”) bore 1993 Dodge Shadow master cylinder (other years and models may work)
• Requires adapters to mate master cylinder outlet to stock lines. The adapter Part number is MC-SF at Disc Brake, Steering and Suspension Products for classic Chevy and Ford cars and trucks.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Easier to find.
• Light in weight.
• Advertised as 7/8”, but may be delivered in a 24mm bore. Measure bore size before you buy.
• Rebuilt/Used ones will have an “8” cast into the front of the aluminium body under the reservoir.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.

24mm (0.944”) bore 1978-1980 GM G-body power brake master cylinders.
• Can buy new or used. Used are fairly cheap. New are fairly expensive.
• Reservoir too small for rear disc brakes. The reservoir from 1979 Buick Riviera with four wheel disc brakes can be retrofitted to this master cylinder.
• Bolt in.
• Come in cast iron and aluminium. 1978-1979 are cast iron. 1980 is aluminium (some models i.e. El Camino).
• New master cylinders will most likely be cast iron regardless of year.
• Rebuilt units come in cast iron and aluminium (1980 – some models).

24mm (0.944”) bore 1993 Dodge Shadow master cylinder (other years and models may work)
• Requires adapters to mate master cylinder outlet to stock lines. The adapter Part number is MC-SF at Disc Brake, Steering and Suspension Products for classic Chevy and Ford cars and trucks.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Easiest to find.
• Light in weight.
• Advertised as 24mm, but may be delivered in a 7/8” bore. Measure bore size before you buy.
• Rebuilt/Used ones will have a “4” cast into the front of the aluminium body under the reservoir.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.

24mm (0.944”) bore 1993 Dodge Dakota master cylinder (other years and models may work)
• Rear brake line outlet is 9/16-20 versus GM rear brake line fitting of 9/16-18. The fitting for GM brake line may be used to “rethread” the master cylinder’s outlet.
• Front brake lines bolt up.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.
• Reservoir not angled like above Dodge and GM master cylinders.

1.0” bore 1979 Buick Riviera with 4 Wheel Disc Brakes.
• Can buy new or used. Used are fairly cheap. New are fairly expensive.
• Reservoir is made for rear disc brakes.
• Bolt in.
• Come in cast iron and aluminium.
• New master cylinders will most likely be cast iron.
• Rebuilt units usually come in aluminium.

1 1/32” (1.03”) bore 1985 Dodge Diplomat master cylinder (other years and models may work)
• Rear brake line outlet is 9/16-20 versus GM rear brake line fitting of 9/16-18. Fitting for GM brake line may be used to “rethread” the master cylinder’s outlet.
• Front brake lines bolt up.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.
• Reservoir not angled like above Dodge and GM master cylinders.

1 1/8” (1.125”) bore 1985 Dodge Ram master cylinder (other years and models may work)• Rear brake line outlet is 9/16-20 versus GM rear brake line fitting of 9/16-18. Fitting for GM brake line may be used to “rethread” the master cylinder’s outlet.
• Front brake lines bolt up.
• Mounting holes spaced 3.25” versus GM master cylinder’s 3.375”.
• Can buy new or used. New ones are fairly cheap to purchase.
• Aluminium body – new, used, or rebuilt.
• Large reservoir can hold enough fluid for rear disc brakes.
• Reservoir not angled like above Dodge and GM master cylinders.
 
#38 ·
One of the main problems that arise when converting to manual brakes using a 7/8" bore master cylinder is LOW drag calipers.

LOW drag calipers require a step bore (quick take up) master cylinder. In my opinion they are too large to operate smaller 2.50" bore calipers with sufficient pressure, they are harder to bleed, and they have a 100lb residual valve that can fail. My opinion also is to change out to new (NOT rebuilt) calipers to make sure you do not get a set of LOW drag calipers.

To learn a little bit about new stock size calipers, I just purchased a set of left and right AFCO 2.5" bore metric calipers that are a bolt in, stock, replacement caliper for g-bodies, S10s, and most 3rd gen f-bodies. I removed the stainless steel piston and square piston seal to make sure it was not a LOW drag caliper.

SPECS:
MFG. Part #: 7241-9003 RH and 7241-9004 LH
Centerline of Holes: 5.50
Caliper Pistons: Single Piston Diameter: 2.50
Inlet fitting: 10mm-1.5 Material Type:
Steel Finish: Natural
Sold in Quantity: Each

Description:
The 2 1/2" bore steel GM metric caliper is designed to be a used as a stock replacement caliper. The caliper features a stock appearing remanufactured castings, remanufactured grounded 2 1/2" stainless steel piston, and low drag seals (see below) . Each caliper is assembled and pressure tested.

LOW DRAG SEALS
Though the description says "low drag seals", the seals are square with no noticable taper.




The seal-groove in the bore of the caliper are also square with no noticable taper.


When the seal is installed, it barely clears the top of the bore, and because of this, the piston to bore clearance, it seams, to have fairly tight tolerances.

The small end of the piston is what contacts the back of the brake pad. It measures 2.38".
The large end of the piston is what is inside the bore of the caliper. It measures 2.50"


Inside of piston cup, facing the brake pad.


Backside of piston that is installed inside the caliper bore.


I have bought these same exact part numbers a few years back and these new ones are a different casting with, what looks to be, a stainless steel piston. These calipers DO NOT come with pads, but they come with slider pins and slider pin bushings. At this time, they are around $40, and seem to be an improvement over the previous design.

Bottom line is that these should be a good stock replacement, NON low drag, brake caliper that will work with both strait bore master cylinders and step bore (quick take up) master cylinders.
 
#39 · (Edited)
Caliper Update:

I have found a good NON low drag (normal) bolt in replacement brake calipers for stock front brake systems. These brake calipers can be used with strait bore (normal) master cylinders and step bore master cylinders.

It is under the Centric Brand. They are about $33 plus shipping at rockauto.com.

Part number are:
14162066
14162065

AFCO has a brand new replacement brake calipers. They are about $49.99 plus shipping. $100 order are free shipping at Summit Racing, Jegs, and Speedway Motors. These should be NON low drag.

The part numbers are:
6635003
6635004
 
#41 · (Edited)
Below is an analysis using the Brake Torque Calculator found on Pro-Touring.com. This calculator will give you an idea of what brake torque is for a certain front and rear setups. I am just going to show the changes from the stock front g-body brake system and compare them to a Blazer dual piston brake swap, a stock LS1 Camaro brake swap, a LS1 Camaro brake swap with Corvette calipers

Page 7, Post #140

Brake sizing and selection tutorial featuring Ron Sutton and Tobin of KORE3 - Page 7
This entire post is a really good read if you are interested about brakes.


Here are the inputs that are the same for ALL different types of brake systems shown below.
• 6 to 1 pedal ratio
• 26” tall tire
• 100 ft/lb pedal pressure
• Manual Brakes – NO POWER ASSIST
• Pad Coefficient of Friction - .45
• Use of stock type (tandem) master cylinder

____________________________________________________
Stock G-body/S10/3rd Generation F-body Front Brake System
• Rotor Diameter – 10.5”
• 7/8” Bore Master Cylinder Area - .601 sq-in
• Line Pressure – 998 psi
• Front Caliper Piston Area – 4.909 sq-in
• Front Clamping Pressure – 4899 pounds
Front Rotor Torque – 964 ft/lb
• Tire Forces – 890 lb
____________________________________________________
Stock LS1 Camaro/Firebird Front Brake System
• Rotor Diameter – 12”
• 7/8” Bore Master Cylinder Area - .601 sq-in
• Line Pressure – 998 psi
• Front Caliper Piston Area – 4.931 sq-in
• Front Clamping Pressure – 4921 pounds
Front Rotor Torque – 1107 ft/lb
• Tire Forces – 1022 lb
____________________________________________________
Stock LS1 Camaro/Firebird Front Brake System with Corvette Calipers with 7/8” bore master cylinder
• Rotor Diameter – 12”
• 7/8” Bore Master Cylinder Area - .601 sq-in
• Line Pressure – 998 psi
• Front Caliper Piston Area – 3.994 sq-in
• Front Clamping Pressure – 3986 pounds
Front Rotor Torque – 897 ft/lb
• Tire Forces – 828 lb

Stock LS1 Camaro/Firebird Front Brake System with Corvette Calipers with 21mm bore master cylinder
• Rotor Diameter – 12”
• 21mm Bore Master Cylinder Area - .537 sq-in
• Line Pressure – 1117 psi
• Front Caliper Piston Area – 3.994 sq-in
• Front Clamping Pressure – 4461 pounds
Front Rotor Torque – 1004 ft/lb
• Tire Forces – 927 lb

____________________________________________________
Stock Blazer Twin Piston Front Brake System
NOTE: The Blazer twin piston front calipers have a piston area too large to run a .875” bore master cylinder. These calculations are using a 24mm bore master cylinder.
• Rotor Diameter – 10.75”
• 24mm Bore Master Cylinder Area - .701 sq-in
• Line Pressure – 856 psi
• Front Caliper Piston Area – 5.152 sq-in
• Front Clamping Pressure – 4410 pounds
Front Rotor Torque – 889 ft/lb
• Tire Forces – 821 lb

Stock Blazer Twin Piston Front Brake System
NOTE: The Blazer twin piston front calipers have a piston area too large to run a .875” bore master cylinder. But to show the differences between the systems, these calculations are using a .875” bore master cylinder.
• Rotor Diameter – 10.75”
• 7/8” Bore Master Cylinder Area - .601 sq-in
• Line Pressure – 998 psi
• Front Caliper Piston Area – 5.152 sq-in
• Front Clamping Pressure – 5142 pounds
Front Rotor Torque – 1036 ft/lb
• Tire Forces – 956 lb


Rating from best to worst:
1. LS1 Camaro / Firebird stock front brakes with 7/8" bore master cylinder.
2. Blazer Twin piston stock front brakes with 7/8” bore master cylinder. NOTE: This setup will not work with a 7/8” bore master cylinder.
3. LS1 Camaro / Firebird front brakes with Corvette brake calipers and a 21mm bore master cylinder. NOTE: A 21mm master cylinders are fairly rare and hard to find.
4. Stock g-body/S10/3rd Generation F-body stock front brake system with 7/8" bore master cylinder.
5. LS1 Camaro / Firebird front brakes with Corvette brake calipers and a 7/8” bore master cylinder.
6. Blazer Twin piston stock front brakes with 24mm bore master cylinder.
 
#43 ·
Since being around brakes a lot since I started manualbrakes.com, sometimes I get a reoccurring question when people are doing the conversion.

What ports do my lines bolt up to?

The ports on all G-body master cylinders have a ½-20 inverted flare port (port closest to the firewall) for the front brakes and a 9/16-18 inverted flare port (port located toward the front of the master cylinder) for the rear brakes. The manualbrakes.com KIT comes with adapters to mate the stock GM line fittings to the MOPAR style master cylinder’s 3/8-24 inverted flare outlets.

For most GM applicatiosn, remember:
Rear port of master cylinder goes to the front brakes.
Front port of master cylinder goes to the rear brakes.
 
#44 ·
Master Cylinder Bleeding Proceedures.

NOTE: DO NOT bench bleed a master cylinder on the car. On a g-body the master cylinder sits at an angle and it WILL NOT get all the air out of the master cylinder. Use a vise to hold the master cylinder level to the ground to bleed the master cylinder of all its air.

I like to use plugs to bleed the master cylinder of air instead of the procedure that uses hoses to recirculate the fluid from the master cylinder ports back up to the reservoir. Why?

When using plugs to close off the ports of the master cylinder, this procedure will let you know if all the air is out of the master cylinder AND if the master cylinder is bad. You don't want to find out your master cylinder is bad after you have it installed and are trying to bleed the rest of the system. You most likely will not get all the air out of the system when your master cylinder is bad. New or rebuilt, it is always good to make sure your master cylinder is in good working order before bolting it onto the car. It will be one less thing you have to trouble shoot if you run into other issues when you are trying to trouble shoot braking issues.

Steps to bleeding a master cylinder:
1. Mount the master cylinder in a vise with the bore of the master cylinder level with the ground. Do not use the top of the reservoir as a guide because is may not be level with the bore of the master cylinder. It may be at an angle versus the bore of the master cylinder.
2. Use the appropriate size solid plugs to plug the outlets of the master cylinder so no fluid can escape the ports.
3. Fill the master cylinder with the appropriate amount of brake fluid.
4. Use a rod to SLOWLY cycle the master cylinder piston in its bore. DO NOT use a flat head or phillips heat screwdriver because they have sharp edges and could harm the bore of the master cylinder. I usually use a nut driver that is used for ¼” drive sockets as a rod because the end does not have any sharp edges and there is a handle to hold onto.
5. After cycling the master cylinder piston SLOWLY a few times, the piston should become rock solid and only move about 1/16 of an inch or less down the bore.
6. After the piston becomes rock solid, push in on the master cylinder piston and hold for 45 seconds. If the piston slowly moves down the bore of the master cylinder, you have a bad master cylinder. If the piston says rock solid and does not move, you master cylinder is good.
7. Mount to your car and bleed the rest of your system starting with the brakes furthest away (passenger rear) from the master cylinder and working your way to the closest (drivers front) brake.
 
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