Rebuilding a Master Cylinder
12-22-2006, 09:27 AM
#1
Pro
Thread Starter
Rebuilding a Master Cylinder
My master cylinder is leaking on my 73. I have a chrome MC and would like to keep it. I see that Zip Products has a MC rebuild kit for $27. Are they reletively easy to rebuild or is this a futile operation?
12-22-2006, 10:43 AM
#4
Race Director
But if there are any pits inside you might want to consider sending it out and and have a SS sleeve put in.If it came from Stainless Steel brakes it might have already been done.
12-22-2006, 10:52 AM
#5
Pro
Thread Starter
Merry Christmas
12-22-2006, 11:10 AM
#7
Le Mans Master
12-22-2006, 12:15 PM
#8
Burning Brakes
12-22-2006, 03:46 PM
#11
Le Mans Master
M/C rebuild lots of pic.
Here ya go.
This is the M/C that is being rebuilt.
Clamp the MC in a vice and push the piston in slightly to releive the force on the snap ring. Use a small screw driver and pry out the ring. Note that some MC may have a Tru-Arc ring which will require Tru-Arc pliers (hardware store item).
Remove the 1st piston and discard, there will be a complete new piston assembly in the rebuild kit.
Turn the MC on end and rap it on a piece of wood to get the 2nd piston out.
Here is all the parts you removed. Note the direction of the lip seals.
You will get new seals for the 2nd piston with the kit but most likely not the piston itself. Remove the spring, retainer and seal. Replace with new parts from the kit. NOTE, depending on the type MC, there may be a thin washer between the seal and the piston flange. There will be 6-8 holes drilled radially around the piston flange and the washer covers them up.
Remove the two seals on the other end of the 2nd piston and replace with those from the kit using clean brake fluid as a lubricant. Pay attention to the direction of the seals on the piston.
Reverse the sequence to reassemble. Liberally lube the pistons and bore with clean brake fluid during assembly.
BE SURE TO BENCH BLEED THE M/C BEFORE INSTALLATION. This will greatly improve the system bleed. Use a couple short pieces of tubing (copper shown here) and connect one end to the M/C ports and the other end into the reservoir. Fill the reservoir with fresh brake fluid. The tubes MUST be submerged in the brake fluid. Slowly push and release the piston until air no longer comes out of the tubes. Remove the tubes and install the cap.
Also as others have suggested, check the condition of the bores. If there is any pitting due to corrosion, you'll need to buy a new MC. I'm sure others will chine in if I missed anything.
Good luck.
This is the M/C that is being rebuilt.
Clamp the MC in a vice and push the piston in slightly to releive the force on the snap ring. Use a small screw driver and pry out the ring. Note that some MC may have a Tru-Arc ring which will require Tru-Arc pliers (hardware store item).
Remove the 1st piston and discard, there will be a complete new piston assembly in the rebuild kit.
Turn the MC on end and rap it on a piece of wood to get the 2nd piston out.
Here is all the parts you removed. Note the direction of the lip seals.
You will get new seals for the 2nd piston with the kit but most likely not the piston itself. Remove the spring, retainer and seal. Replace with new parts from the kit. NOTE, depending on the type MC, there may be a thin washer between the seal and the piston flange. There will be 6-8 holes drilled radially around the piston flange and the washer covers them up.
Remove the two seals on the other end of the 2nd piston and replace with those from the kit using clean brake fluid as a lubricant. Pay attention to the direction of the seals on the piston.
Reverse the sequence to reassemble. Liberally lube the pistons and bore with clean brake fluid during assembly.
BE SURE TO BENCH BLEED THE M/C BEFORE INSTALLATION. This will greatly improve the system bleed. Use a couple short pieces of tubing (copper shown here) and connect one end to the M/C ports and the other end into the reservoir. Fill the reservoir with fresh brake fluid. The tubes MUST be submerged in the brake fluid. Slowly push and release the piston until air no longer comes out of the tubes. Remove the tubes and install the cap.
Also as others have suggested, check the condition of the bores. If there is any pitting due to corrosion, you'll need to buy a new MC. I'm sure others will chine in if I missed anything.
Good luck.
Last edited by Duke94; 01-27-2007 at 07:46 PM. Reason: Added more info
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vrazumihin (02-13-2022)
12-23-2006, 05:35 AM
#12
Pro
Thread Starter
Here ya go.
Clamp the MC in a vice and push the piston in slightly to releive the force on the snap ring. Use a small screw driver and pry out the ring. Note that some MC may have a Tru-Arc ring which will require Tru-Arc pliers (hardware store item).
Remove the 1st piston and discard, there will be a complete new piston assembly in the rebuild kit.
Turn the MC on end and rap it on a piece of wood to get the 2nd piston out.
Here is all the parts you removed. Note the direction of the lip seals.
You will get new seals for the 2nd piston with the kit but most likely not the piston itself. Remove the spring, retainer and seal. Replace with new parts from the kit. NOTE, depending on the type MC, there may be a thin washer between the seal and the piston flange. There will be 6-8 holes drilled radially around the piston flange and the washer covers them up.
Remove the two seals on the other end of the 2nd piston and replace with those from the kit using clean brake fluid as a lubricant. Pay attention to the direction of the seals on the piston.
Reverse the sequence to reassemble. Liberally lube the pistons and bore with clean brake fluid during assembly.
Also as others have suggested, check the condition of the bores. If there is any pitting due to corrosion, you'll need to buy a new MC. I'm sure others will chine in if I missed anything.
Good luck.
Clamp the MC in a vice and push the piston in slightly to releive the force on the snap ring. Use a small screw driver and pry out the ring. Note that some MC may have a Tru-Arc ring which will require Tru-Arc pliers (hardware store item).
Remove the 1st piston and discard, there will be a complete new piston assembly in the rebuild kit.
Turn the MC on end and rap it on a piece of wood to get the 2nd piston out.
Here is all the parts you removed. Note the direction of the lip seals.
You will get new seals for the 2nd piston with the kit but most likely not the piston itself. Remove the spring, retainer and seal. Replace with new parts from the kit. NOTE, depending on the type MC, there may be a thin washer between the seal and the piston flange. There will be 6-8 holes drilled radially around the piston flange and the washer covers them up.
Remove the two seals on the other end of the 2nd piston and replace with those from the kit using clean brake fluid as a lubricant. Pay attention to the direction of the seals on the piston.
Reverse the sequence to reassemble. Liberally lube the pistons and bore with clean brake fluid during assembly.
Also as others have suggested, check the condition of the bores. If there is any pitting due to corrosion, you'll need to buy a new MC. I'm sure others will chine in if I missed anything.
Good luck.
We'll see what the condition of the bores are when I get it apart. Hope I can keep this MC.Merry Christmas!
Chris
05-06-2021, 11:12 PM
#13
sorry for the revive but @Duke94 would be able to either 1) reload the pictures you posted since they are showing up as "Sorry, this image is currently unavailable" (I have no idea why some pics do that on this forum, it seems like after a certain period of time elapses since upload, the forum whites out the pic and puts that message???) or 2) send them over to my build thread page: https://www.corvetteforum.com/forums...ld-thread.html
Whichever would be easiest for you! Thank you in advance. I am currently searching how to re install the plungers/springs back in the cylinder (a friend disassembled it for inspection and cleaning/painting and I did not see the order of the parts as he pulled them out)
Whichever would be easiest for you! Thank you in advance. I am currently searching how to re install the plungers/springs back in the cylinder (a friend disassembled it for inspection and cleaning/painting and I did not see the order of the parts as he pulled them out)
05-07-2021, 07:02 PM
#15
05-08-2021, 08:10 PM
#16
I have been following this and another master cylinder rebuild thread. Thanks for the info.
My MC looked a lot like the OP's with one exception. My bore is pitted. I also have the booster that looks like brake fluid has leaked into it. I am in the process of pulling it. I am going the rebuild route through Rock Auto.
My MC looked a lot like the OP's with one exception. My bore is pitted. I also have the booster that looks like brake fluid has leaked into it. I am in the process of pulling it. I am going the rebuild route through Rock Auto.
05-10-2021, 08:12 PM
#17
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sorry for the revive but @Duke94 would be able to either 1) reload the pictures you posted since they are showing up as "Sorry, this image is currently unavailable" (I have no idea why some pics do that on this forum, it seems like after a certain period of time elapses since upload, the forum whites out the pic and puts that message???) or 2) send them over to my build thread page: https://www.corvetteforum.com/forums...ld-thread.html
Whichever would be easiest for you! Thank you in advance. I am currently searching how to re install the plungers/springs back in the cylinder (a friend disassembled it for inspection and cleaning/painting and I did not see the order of the parts as he pulled them out)
Whichever would be easiest for you! Thank you in advance. I am currently searching how to re install the plungers/springs back in the cylinder (a friend disassembled it for inspection and cleaning/painting and I did not see the order of the parts as he pulled them out)