I'm trying to find out the bore size of the piston in the rear brake master cylinder. Can anyone tell me what size it is?
SOURCE: rear brake not holding pressure , pedal goes to the floor
Is your rear rotor warped? if the rotor is warped it will push the pads out causing you to have to pump them to stop.Remember the dot 5 is aeroscopic. if you shake or drop the bottle of fluid, you cannot use it for at least 24 hours. it will continue to create air in itself for that long. so even if you bleed the system correctly it will continue to introduce air into the system.
I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_5bac37c3cb991fdb
SOURCE: i have a 2005 heritage softail classic i need to
I think your rear master cylinder is 5/8" in diameter since it is only a single disc in the rear brake. Dual disc front brakes usually have the larger 3/4" diameter master cylinder. If you take the master cylinder apart, you can either measure the bore or look on the rubber "cup". The size is usually on the cup.
SOURCE: how to unscrew the master cylinder piston from the
Having never messed with part on a Dyna Wide Glide I'm not sure. Is there a lock nut on the rod? If so, loosen that and see if the rod will turn out. If not, something else has to come off so that you can get to whatever the rod is screwed into. I doubt it's screwed into the piston or plunger as this part MUST be free to move with out hinderance of anything connected firmly to it.
Good Luck
Steve
SOURCE: I hit something in the
No problem, just change the old one out with the new one, fill the master cylinder reservior and bleed the brakes. To bleed the brakes, do this in EXACTLY this order. Fill the master cylinder. Press the rear brake pedal and hold it down. Open the bleeder valve on the rear caliper and allow brake fluid and air to bleed out. Close the bleeder valve. Let off on rear brake pedal. Repeat process until you have a full firm pedal. Do not allow the master cylinder to run dry during the bleeding process.
Good Luck
Steve
SOURCE: FILL UP REAR MASTER CYLINDER WITH BRAKE FLUID
If you don't have a leak somewhere, you have air in the system. When "pump up" the brakes, you use the brake fluid to compress the air in the system and the pedal feels good for a while. When the compressed air finally forces the brake fluid back into the master cylinder reservoir, the air is no longer compressed and the pedal feels soft. You need to bleed the brakes. Follow these instruction in exactly this manner. First, check the master cylinder reservoir to make sure it's full. Put the cover back on the reservoir so the brake fluid does not splash out. Depress and hold the rear brake pedal. Open the brake bleeder valve on the rear brake caliper and allow the air and fluid to flow out. Close the bleeder valve. Release the rear brake pedal and check the fluid level in the master cylinder reservior. Repeat as many times as necessary until the brake pedal is firm. Do not allow the reservoir to run dry during this process. By putting a short piece of clear plastic tubing on the brake bleeder valve you can direct the expelled fluid into a catch container and reduce the mess. Do not allow brake fluid to get on the painted surfaces of the bike and use only the type of brake fluid that is specified on top of the master cylinder reservoir or in the owner's manual. On your bike that would be DOT 5. Do not mix with any other type of fluid.
501 views
Usually answered in minutes!
The brake master cylinder is fine! I need to know the bore size as my Dyna Lowrider has been triked. And I'm trying to work out the brakes to run two discs on the back of my trike. This being the case, I need to find out the bore size. I don't really want to take apart my master cylinder to size it up, as you can not get a rebuild kit for the Dyna master cylinder. Just thought, maybe someone might know the exact size. Many thanks....
Why do you need the size? If the master cylinder is bad, just go to the dealer and buy a rebuild kit. If you can't find the size, disassemble the master cylinder and measure the bore with dial calipers or ruler.
×